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MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG TD TF 1500 - Under the floor board securing the seat rails?

It would appear that the PO decided to put some heat shield mat under the carpets. The seat rails are "secured" by the bolts pushed through the rail into the hole in the floor board. They were not long enough now, so there is nothing securing them at all, no nut or anything. The bolt ends are flush with the underside of the board! I have looked at the Abingdon Spares web site and it is not clear to me what should be there. Is it a large washer and a nut? Does anyone have a reference photo of this from below?

Thanks much
Simon

S Griffin

Not sure what these are called, but they insert from the bottom and are held in with tacks. Bolts screw into these and pull track tight to floorboards. George


George Butz

As George notes, there are T-Nuts, under the floor boards that accept bolts from above to secure the rails to the floor boards.
These are generally secured to the wood with FH nails that are bent and then peened over.
Some times the holes for the nails have become enlarged and the nails will not hold.

I tried two things. I first tried wood screws. Some worked some did not.
I then made a ring, that fits over the barrel of the t-nut with threaded holes. I used machine screws into the ring and filed the screws flat so nothing protruded.

Attached is a pix of the original t-nut attached to the bottom of the floor boards.

Jim B.


JA Benjamin

If you fix 1/2" x 1" strips of wood to the floor for the seat rails to rest on you can cut slots in the carpet to fit around these and if you slit the carpet under the seat the carpet can be removed for cleaning or more likely drying out.

Jan T
J Targosz

This is very helpful indeed. Thank you.
S Griffin

AKA nut-serts
S Cole

Simon -

That's why I don't feel that any extra insulation should be used on the floor boards other than the felt padding that comes with the carpet kit (Moss) Foam and aluminum backed insulation will trap moisture. No insulation or padding on the bottom of the floorboards.

Unfortunately I don't believe that reproductions of the original style BSF Tee-Nuts that are shown in Jim B's photo are available. However the ones shown in George Butz's post with modern threads are very similar to the orignals.

I used copper carpet tacks to hold the original TeeNuts in position in my new floorboards.

Here is info on the locations, types and sources of the original bolts and floorboard washers. However, if you must replace the TeeNuts, then use modern fine thread bolts and TeeNuts of the same diameter as the original BSF fasteners.

> Floorboard fasteners:
Search the Archives for Thread Title:
Floorboard/prop shaft supports

Look at the third post (LM Cook) for answers on locations and types of fasteners.

Link to diagram:
http://drive.google.com/file/d/0BxisXBEpc-IWa25XaHc4akNPd28/view?usp=sharing

Error in the diagram and parts list:
8L
8R
Do not use floorboard washer under 8L and 8R. The floorboard are routed 1/4" deep to clear the hex heads. Flat washers or split washers may cause the hex head to sit too high. Investigate.

> Location of holes and fasteners for seat rails: Search the Archives for Thread Title:
TF seat slide position

Lonnie
TF7211
LM Cook

Modern tee nuts or nutserts have 3 or 4 little barbs built in so you won't have little tacks falling out.

That is, if you have lost your original mounting hardware.

like this:
http://www.dkhardware.com/product-22415-tn1024z-tee-nut-for-1-2-standoffs.html?gclid=CIH6p-z1l9ECFfQW0wod-A8Hsg
D mckellar

I have had very poor results with modern t-nuts staying in plywood.
I had several 10-32' (BA2) fall out of the seat bottom after being covered.

I save that with threaded in inserts.

The modern ones do stop the nut from turning, but you must have somebody to hold them as you screw the 5/16-BSF bolt in from the cockpit side or they push out easily.

I seem to remember that a member found the proper t-nuts at either Moss or Abingdon.

I made new ones out of 303 SS, since I wanted to prevent the bolts from rusting in place. I suppose one could use anti-seize.

Jim B.
JA Benjamin

T-Nuts at Home Depot also in Metric. 4 pack
M Grogan

Does anybody have a partnumber for a BSF t-nut?
John van den Boorn

Simon -

The seat rails were secured by 5/16" BSF fine thread round tee nuts inserted from the bottom of the plywood floorboards. I don't believe that BSF tee nuts are available from the usual suppliers.

The tee nuts have three holes for tacks and have three cones that press into the plywood floor. A tack is nailed through each of the three holes and cinched over to prevent the tee nut from falling out out when inserting the 5/16" hex head BSF machine screws to hold the hinged protion of the seat rails.

A flat washer goes between the hex head and the hinged seat rail. Optionally, two short wood screws can secure the rear of each seat rail.

If the holes in your plywood floorboards are enlarged and damaged, then you will need to use bolts, nuts, and washers to secure your seat rails. A better solution is to make new floorboards from 3/8" marine plywood. Use Roy Challberg's plans as a guideline. Make an oversize template, then trim to fit. Pattern route the new floorboards using your template. I listed links to fasteners and tips in my previous post.
http://www.ttalk.info/MG%20Floorboards%20Rev%206.pdf

===

MODERN TEE NUTS FOR FLOORBOARDS

Eight tee nuts are used in the two floorboards.

> Four round 5/16" BSF = S1L, S2L, S1R, S2R (for the seats)
> One round 1/4" BSF = 1R
> Three narrow rectangular 1/4" BSF = 1L, 13L 13R

The original round tee nuts had three holes for tacks that were cinched over. and three cones that pressed into the plywood. The original rectangular tee nuts had two holes for tacks. All were BSF threads.

Modern barb-type tee nuts can work loose and fall out when assembling. "BRAD HOLE" tee nuts can be secured with tacks inserted through holes in the base, and then clinched over to hold.

All modern tee nuts that I have seen are course thread SAE or Metric.

McMaster-Carr has round unplated steel 1/4-20 and 5/16-18 brad hole "Screw-Mount" course-thread tee nuts that have three holes for tacks and have three cones that press into the plywood, similar to the original round tee nuts. The threaded section on the 1/4-20 tee nut may need to be shortened.
http://www.mcmaster.com
1/4-20 = #90611A600
5/16-18 = #90611A610

1/4-20 and 5/16-18 stainless steel brad hole tee nuts without cones are available at Lowes and Home Depot.
http://www.lowes.com/pd/The-Hillman-Group-1-4-in-Stainless-Steel-Standard-SAE-Brad-Hole-Tee-Nut/3025380
http://www.lowes.com/pd/The-Hillman-Group-5-16-in-Stainless-Steel-Standard-SAE-Brad-Hole-Tee-Nut/3025381

Most modern brad hole rectangular tee nuts are not as long and narrow as the original tee nuts.
http://www.menards.com/main/tools-hardware/fasteners-fastener-accessories/nuts/tee-nuts/1-4-20-x-1-4-rectangular-brad-hole-tee-nuts-9-pcs-box/p-1444439873178.htm

Stainless steel 1/4-20 and 5/16-18 flat head Phillips and slotted screws are available from most large hardware stores and suppliers.

Mark each non-BSF hole to avoid damage by inserting BSF screws into them.

Original style floorboard washers are available from:
> From the Frame Up - #WAC0414
> Abingdon Spares - #41 073a

Photo:
Top = Original 5/16 BSF round tee nut for seat rails.
Center = Two rectangular 1/4" BSF tee nuts - driver side, front.
Bottom = One round and one rectangular 1/4" BSF tee nut passenger side, front,

Lonnie
TF7211


LM Cook

If you want to make your own, here is how I did mine.
Top left frame gives dimensions.
Top right are the parts. Note that there are also little pins thst are supposed to lock the nut from turning, in addition to the nails.

Bottom left, Top side, original on left fabricated one on the right.

Bottom Right Bottom side, again original one on the Left.

I silver BRAZED the parts together.
Flange was 303, body was 304 tubing. I did have trouble threading the tubing. Even with a new tap. If I were to make them over I would use 303 rod.


JA Benjamin

It were always my understanding that the TF used wood screws (original from factory) like the other t-types did to hold the seat hardware to floor wood. Same understanding that near all replacement floor wood were/are sold with nut-serts, either the kind with spikes or holes for tacks.

Even MGA Guru thinks nobody really knows for sure on the later MGA's. I really like the spiked kind pictured in the Guru article at bottom. Interesting reading, might be of relevance for TF people. Looks like these inserts started getting used by MG factory sometime during MGA production. Maybe?
http://mgaguru.com/mgtech/frame/fr111b.htm


My question is that though these inserts are with no question bettter than wood screws, is there really any expert or factory proof they were used here by the factory? Or is that just what people figure because thats what they found in their "original" TF with replacement BMC floor wood from 1965?

JA Benjamin, those are nice. Good advice about stainless. It "can" be really hard to cut or drill, etc.
S Cole

S Cole
I purchased my TD in 1966 only 14 years after manufacturer.
Even then the floor boards were so decrepit I believe they had to be original.
They had captive or T-Nuts.
I did not replace the floor boards. I "repaired" them. Only the front 1/3 was bad. I grafted new fronts on.
The plywood is 3/8. I do not believe wood screws would hold a seat anchored only in 3/8 wood.
There is no evidence of any backer wood below the seats.

Jim B.
JA Benjamin

Jim -

Those are beautiful. I admire your creativity and craftsmanship.

Lonnie
TF7211
LM Cook

Thank you Lonnie, also S Cole.
Jim B
JA Benjamin

Original TD floor showing T nuts securing the seat as Jim suggests. Wood screws were definitely NOT original. Cheers
Peter TD 5801


P Hehir

T nuts were also use to secure the sliding cover for the brake master cylinder on the TD. See pic. Cheers
Peter TD 5801


P Hehir

"My question is that though these inserts are with no question better than wood screws, is there really any expert or factory proof they were used here by the factory?" Positively they were used at the front of the seat slide on TDs ant TFs, and I think at least one other near the pedal box or tranny cover on LHD cars. There is no proof that the sun will rise in the morning either...
George
George Butz

Well, now I know what these T nuts look like it would appear that I have found one in a plastic bag that was in the glove box. I need to get the clutch bled on my B today, and since it is currently up on my axle stands I will then get the TD up on the stands and see what else I can find. I do believe that my car has its original floorboard, it will be interesting to see what I find when I can really get to it.

This has turned into a rather fascinating discussion with some incredible insight and solutions put forth. Thankyou all for your contribution. I most certainly have a way forwards now.
S Griffin

George B,

I enjoyed your comments ! Of course,originally all TFs had the T nuts(5/16", BSF) affixing the front of the seat runner 'hinges' to the floorboards.The rear of the runners were held down by purile woodscrews into the floorboard ie. the seats originally did not tilt forward.

Peter H. is correct also in that two(2) (3/16", BSF ?) T nuts affixed the
master cylinder plate cover to the floorboard on rhd vehicles.

Cheers
Rob Grantham
Rob Grantham

There is an advantage of being able to tip the seats up in our climate here. I have been caught in torrential rains a few times and it is great to tip the seat up to let stuff dry out! Just curious what was used on LHD very early TD's with the MC cover plate? George
George Butz


"My question is that though these inserts are with no question better than wood screws, is there really any expert or factory proof they were used here by the factory?" Positively they were used at the front of the seat slide on TDs ant TFs, and I think at least one other near the pedal box or tranny cover on LHD cars. There is no proof that the sun will rise in the morning either...
George

Thing is Geo the MG factory was always "run" by a bunch of bean-counters. I'm sure they thought so anyway. Disputes today on originality for the post war t-types and through the MGA production can usually be settled by factory documents. "Service parts lists" and the like, even for floor woods that were probably made up by an outside vendor, will specify exactly how many and what sort of nut, screw, washer, tee-nut and brass tacks were involved in each floor piece. You know, proof. Have not seen any of that yet. Nothing beats a factory list.

P Hehrir shows some old boards and says they are original. How does he know they are original, and (if indeed orig.) were not modified with tee nuts when wood screws no workie no more? How can the validity of these assertions be determined without some explanation of why he thinks they are original and unmodified?

Rob G says with a sure attitude it was wood screws and tee nuts. Where is this certainty come from?
S Cole

Its simple,I have stripped out seven(7) TFs with the original floorboards and ALL had the T nuts in the same position as described. Some had the wood screws in position at the rear also with others having the screw hole left over.

Cheers
Rob Grantham
TF3719("Aramis"),TF9177("Athos").
Rob Grantham

Some had wood screws? Now were you working at a Brit car accident repair shop when these cars were "new" so you could be so sure the floorsboards were new? Were these 7 cars over the last 20 years, 5 years? I have seen t-types that needed new floors when they were 5 years old. Could the floors you stripped out have been aftermarket replacements? Were the t-nuts identical? Or have you some authoritative restoration reference book you can share the title of that discusses this, or the factory Service Parts List no. or know where to find a copy of the actual SPL for the boards? The main cause of erroneous restorations (not actually to original spec) over the years on these cars seems to stem from either replacement parts that became standardized wrong over the years or based on "original" cars that really were not. No SPL's on TF's?
S Cole

Thanks Rob. I also have seen about the same number of original TD floorboards that were removed from cars & stored in the fifties & sixties when they were being parted out after a prang. The pics I attached are of an original floor. I also know of at least two cars here that still have their original floors, both with T nuts. Absolutely no doubt about the T nuts being original. I also have purchased a set of 4 x 5/16" BSF T nuts from either Abingdon or FTFU a few years ago, I can't remember which. Again these were sold as original components. Hopefully that now settles that.. Cheers
Peter TD 5801
P Hehir

There are two possible postulates. The T-nuts are factory.
The T-Nuts are replacements.

Let's assume, for a moment, that the floor boards that Rob has seen had screws replaced with T-nuts. Also that both Peters and mine and many more in the US were replaced.

Our cars are separated by 10000 miles.
How did exactly the same BSF -5/16 T-Nuts get affixed in exactly the same way with bent and clipped nails.
In those days, when authenthicity was not paramount a US user would use UNC T-Nuts.

Occams Razor requires one to choose the simpler explanation. They came from the factory that way.

Jim B
JA Benjamin

Page 40 of the Drivers Handbook (TD) and Operation Manual (TF) both show an illustration for universal joint lubrication which just happens to capture an image of one of the T nuts for the left seat.

Matthew.
M Magilton


Let me explain how it really was. I was there.
There was only just one replacement floor maker back then, selling to US, Europe, AUS etc. to British Motors. Back then more people knew about the real world advantages of having BSF threads in a car like the MG. Practically a genuine self locking thread form. It was a sales gimmick to get people to buy. The "better than original" "new and improved" self locking BSF nutsert pre-installed in the improved rot resistant new plywood--to hold your seat where it should be. People loved the idea-- what with rumors flying about people crashing their new TF's simply because those wood screws were no good and coming loose, causing mayhem on the roads, and those crashes were from cheapskates who didn't want to spend a few bucks. Economy of scale and all, and "British" threads of course sounded right. BSF all around. No mystery, just how they made them all for the whole world around. Only mystery was why they kept crashing all those newish TF's like P Herir saw all the time with the new replacements with BSF nutserts? Same story on the bent and clipped tacks, It is just how all the replacements were done up. Simple. Since there were very few do-it-yourselfers back then when for car stuff, and besides you could just go buy new ones for the price of a couple of gin cocktails at the local bar. Everybody just bought the floor kits from their friendly parts counter man they were getting to know real good at their nearest British motors. My uncle Lovell worked the parts counter on weekends at BMC in Chicago (stock exchange boys liked those TF's). So a fella would go pick up a tune up kit and wires for his first tune up on the 6 month old TF and guess what? A special deal on replacement floors complete with all the "fancy" BSF hardware installed or included. "Good customer discount" and all, he liked to make any customer feel like one of the family to get him to buy more stuff. "Wouldn't want YOU to crash your car! He would say "they wont last long," and "those screws will be working loose any time now." When a tightwad would come in and not want to buy the floor kits he would say something like "guess your life insurance is all paid up this month." He got some people to buy new floors every year with "don't you notice the fresh pine scent has faded?" During the summer I would earn extra cash with Lovell. He would tell parts counter customers about how I was one of the youngest Engineering full professor's at McCormick at Northwestern. Actually I was the youngest, not one of the youngest full professors. It was fun spending time with Lovell getting people to buy stuff they didn't need. He would tell them how I was designing "nukular rockets" for the Army or something and how about I go out and take a look at their car and see if I can spot any maintenance items they needed? We sold a lot of steering and suspension components with my "inspections" because they really needed them replaced. Not sure what people were driving over to wear stuff out so fast, but they were. Not to mention all the gold seal engines when people would plead with Lovell to let them take me for a ride to see if I can hear that engine noise. I usually could.
'
S Cole

Pretty convincing Matthew. Thanks mate. About the only other thing I could add is that there are none so deaf... Cheers
Peter TD 5801
P Hehir

Sheet 33 of 35, MG-TD Specifications Book dated 1951 (this is a copy of an original book, so the Russians didn't hack it...): FS.105-6 Set Screw, Hex.Head. 3/4"x5/16" BSF No. OFF- 4, Seat slides to Floor. Sheet No. 24/3 PW105.Z516 5/16"x5/8" x.072" Plain Washer No. Off 4, Seat runner bolts. Somewhere else there is a spec for a bunch of 5/16ths T-nuts listed as used in many places (some round, some T-shaped). Of course this raised the question- if 4 were used, then you couldn't tip the seat base up, so why were they hinged?? George
George Butz

George, wouldn't four just indicate one at the front of each of the four seat runners? Bud
Bud Krueger

Since there were very few do-it-yourselfers back then when for car stuff, and besides you could just go buy new ones for the price of a couple of gin cocktails at the local bar.


WRONG!

In those post depression days everyone was a "Shade Tree" mechanic.

I was there also.

Jim B.
JA Benjamin

Bud, I was thinking of just one seat for some reason! George
George Butz

Well, Interesting to read so much discussion about a topic. I seldom come to the BBS now as there is usually enough people responding with the correct information.

However my factory assembly sheets do not show the 4 seat runner Tee nuts as they describe the floors both LHD and RHD as "supplied by Bodies Branch".

The build sheets do describe the other Tee Nuts in the floors. I copy as listed.

93280 Oblong Tee Nut 1/4" BSF 3 floorboard, 4 rear platform battens.

105518 Round Tee Nut 2BA 2 floorboard inspection plate RHD.

FS.105-6 Set Screw Hex head 3/4" x 5/16" BSF 4 off seat slides floor.
I have not listed the washers as these are self explanatory.
(NB no nuts are listed for these bolts so we must assume the nuts are in the ply from bodies Branch.)

The inspection cover plate screws are,
236D/1 no2 BA x 5/16" RD HD screw 2 off.

I have completed 30 TF restorations and 10 TDs, since 1969, almost all had their original floor boards and all had Tee Nuts. ( "Tee Nut" being the factory term used)

If the factory used Tee nuts to secure the steel cover plate that has no support requirement and also used Oblong Tee Nuts to hold the diff inspection ply section that also is not supporting anything like the weight of seats and people on seat slides, it would be senseless and not good practice for the factory to secure the front of the seat slides with only wood screws.

The MGA also used Tee Nuts to hold down the seat slides 8 in total. We have restored a number of MGA's also.

I think 40 T types is a good enough sampling of vehicles to confirm TD/TF had 4 "Tee Nuts" at the front holding the seat slides originally. I have been there since 1969.


Rod Brayshaw

Thank you Rod. I have an original pair of floor boards on loan (see pics above) & am yet to determine the size of the MC cover Tee Nuts. I do have a box of brass 2BA screws & a 2BA tap which I'll now use to confirm the size you've posted. I fully expect to find that they are indeed 2BA. I totally agree with your comment that "it would be senseless and not good practice for the factory to secure the front of the seat slides with only wood screws." The Brits had a habit of over-engineering everything so the suggestion that securing the seats with just a couple of wood screws made no sense to me at all. Cheers
Peter (Hehir) TD 5801
P Hehir

The above info. just confirms what we knew to be the original fixing
method for the seat slides,5/16" BSF set screws into Tee Nuts. There were/are two(2) per seat.

I have been rebuilding/restoring TFs for only 41 years whereas Rod B has been at it for 48 years !!

Happy and informative New Year 2017.

Cheers
Rob Grantham
TF3719("Aramis"),T9177("Athos").
Rob Grantham

Pic shows one of the two MC cover Tee Nuts in an original floorboard with a 2 BA screw partially inserted thus confirming Rod's advice. This answers one of my questions on the flooring detail & is another example of Abingdon's mixed use of both BSF & BA threads in the T types. Also thanks to Simon for initiating this thread. Cheers
Peter TD 5801


P Hehir

Peter,

I just love it!

Cheers
Rob Grantham
Rob Grantham

Seemed like an innocent enough question! Stunned by the depth of discussion. Thanks everyone and Happy New Year!
S Griffin


I never thought much about how the seat runners were secured in TF's and TD's. Sounds like T-nuts. The TC seat bottoms fit so precisely between the tub and the differential cover that each seat runner was secured entirely by three wood screws through the front part of the runner hinge (into the wood floor). 12 screws total both seat bottoms/4 runners. Nothing else. Remove the seat back and you can flip the seat bases up/forward. Installed, the seat back does not allow the seat bottoms to lift. Sounds like they are really bolted down in the TD/TF.

Not a single T-nut was originally used anywhere on a TC. The floors were held down with special bolts and captive nuts welded to the chassis.

So, it sounds like MG began using T-nuts in the TD.




D mckellar

It would appear that the PO decided to put some heat shield mat under the carpets. The seat rails are "secured" by the bolts pushed through the rail into the hole in the floor board. They were not long enough now, so there is nothing securing them at all, no nut or anything. The bolt ends are flush with the underside of the board! I have looked at the Abingdon Spares web site and it is not clear to me what should be there. Is it a large washer and a nut? Does anyone have a reference photo of this from below?

Thanks much
Simon

S Griffin

Not sure what these are called, but they insert from the bottom and are held in with tacks. Bolts screw into these and pull track tight to floorboards. George


George Butz

As George notes, there are T-Nuts, under the floor boards that accept bolts from above to secure the rails to the floor boards.
These are generally secured to the wood with FH nails that are bent and then peened over.
Some times the holes for the nails have become enlarged and the nails will not hold.

I tried two things. I first tried wood screws. Some worked some did not.
I then made a ring, that fits over the barrel of the t-nut with threaded holes. I used machine screws into the ring and filed the screws flat so nothing protruded.

Attached is a pix of the original t-nut attached to the bottom of the floor boards.

Jim B.


JA Benjamin

If you fix 1/2" x 1" strips of wood to the floor for the seat rails to rest on you can cut slots in the carpet to fit around these and if you slit the carpet under the seat the carpet can be removed for cleaning or more likely drying out.

Jan T
J Targosz

This is very helpful indeed. Thank you.
S Griffin

AKA nut-serts
S Cole

Simon -

That's why I don't feel that any extra insulation should be used on the floor boards other than the felt padding that comes with the carpet kit (Moss) Foam and aluminum backed insulation will trap moisture. No insulation or padding on the bottom of the floorboards.

Unfortunately I don't believe that reproductions of the original style BSF Tee-Nuts that are shown in Jim B's photo are available. However the ones shown in George Butz's post with modern threads are very similar to the orignals.

I used copper carpet tacks to hold the original TeeNuts in position in my new floorboards.

Here is info on the locations, types and sources of the original bolts and floorboard washers. However, if you must replace the TeeNuts, then use modern fine thread bolts and TeeNuts of the same diameter as the original BSF fasteners.

> Floorboard fasteners:
Search the Archives for Thread Title:
Floorboard/prop shaft supports

Look at the third post (LM Cook) for answers on locations and types of fasteners.

Link to diagram:
http://drive.google.com/file/d/0BxisXBEpc-IWa25XaHc4akNPd28/view?usp=sharing

Error in the diagram and parts list:
8L
8R
Do not use floorboard washer under 8L and 8R. The floorboard are routed 1/4" deep to clear the hex heads. Flat washers or split washers may cause the hex head to sit too high. Investigate.

> Location of holes and fasteners for seat rails: Search the Archives for Thread Title:
TF seat slide position

Lonnie
TF7211
LM Cook

Modern tee nuts or nutserts have 3 or 4 little barbs built in so you won't have little tacks falling out.

That is, if you have lost your original mounting hardware.

like this:
http://www.dkhardware.com/product-22415-tn1024z-tee-nut-for-1-2-standoffs.html?gclid=CIH6p-z1l9ECFfQW0wod-A8Hsg
D mckellar

I have had very poor results with modern t-nuts staying in plywood.
I had several 10-32' (BA2) fall out of the seat bottom after being covered.

I save that with threaded in inserts.

The modern ones do stop the nut from turning, but you must have somebody to hold them as you screw the 5/16-BSF bolt in from the cockpit side or they push out easily.

I seem to remember that a member found the proper t-nuts at either Moss or Abingdon.

I made new ones out of 303 SS, since I wanted to prevent the bolts from rusting in place. I suppose one could use anti-seize.

Jim B.
JA Benjamin

T-Nuts at Home Depot also in Metric. 4 pack
M Grogan

Does anybody have a partnumber for a BSF t-nut?
John van den Boorn

Simon -

The seat rails were secured by 5/16" BSF fine thread round tee nuts inserted from the bottom of the plywood floorboards. I don't believe that BSF tee nuts are available from the usual suppliers.

The tee nuts have three holes for tacks and have three cones that press into the plywood floor. A tack is nailed through each of the three holes and cinched over to prevent the tee nut from falling out out when inserting the 5/16" hex head BSF machine screws to hold the hinged protion of the seat rails.

A flat washer goes between the hex head and the hinged seat rail. Optionally, two short wood screws can secure the rear of each seat rail.

If the holes in your plywood floorboards are enlarged and damaged, then you will need to use bolts, nuts, and washers to secure your seat rails. A better solution is to make new floorboards from 3/8" marine plywood. Use Roy Challberg's plans as a guideline. Make an oversize template, then trim to fit. Pattern route the new floorboards using your template. I listed links to fasteners and tips in my previous post.
http://www.ttalk.info/MG%20Floorboards%20Rev%206.pdf

===

MODERN TEE NUTS FOR FLOORBOARDS

Eight tee nuts are used in the two floorboards.

> Four round 5/16" BSF = S1L, S2L, S1R, S2R (for the seats)
> One round 1/4" BSF = 1R
> Three narrow rectangular 1/4" BSF = 1L, 13L 13R

The original round tee nuts had three holes for tacks that were cinched over. and three cones that pressed into the plywood. The original rectangular tee nuts had two holes for tacks. All were BSF threads.

Modern barb-type tee nuts can work loose and fall out when assembling. "BRAD HOLE" tee nuts can be secured with tacks inserted through holes in the base, and then clinched over to hold.

All modern tee nuts that I have seen are course thread SAE or Metric.

McMaster-Carr has round unplated steel 1/4-20 and 5/16-18 brad hole "Screw-Mount" course-thread tee nuts that have three holes for tacks and have three cones that press into the plywood, similar to the original round tee nuts. The threaded section on the 1/4-20 tee nut may need to be shortened.
http://www.mcmaster.com
1/4-20 = #90611A600
5/16-18 = #90611A610

1/4-20 and 5/16-18 stainless steel brad hole tee nuts without cones are available at Lowes and Home Depot.
http://www.lowes.com/pd/The-Hillman-Group-1-4-in-Stainless-Steel-Standard-SAE-Brad-Hole-Tee-Nut/3025380
http://www.lowes.com/pd/The-Hillman-Group-5-16-in-Stainless-Steel-Standard-SAE-Brad-Hole-Tee-Nut/3025381

Most modern brad hole rectangular tee nuts are not as long and narrow as the original tee nuts.
http://www.menards.com/main/tools-hardware/fasteners-fastener-accessories/nuts/tee-nuts/1-4-20-x-1-4-rectangular-brad-hole-tee-nuts-9-pcs-box/p-1444439873178.htm

Stainless steel 1/4-20 and 5/16-18 flat head Phillips and slotted screws are available from most large hardware stores and suppliers.

Mark each non-BSF hole to avoid damage by inserting BSF screws into them.

Original style floorboard washers are available from:
> From the Frame Up - #WAC0414
> Abingdon Spares - #41 073a

Photo:
Top = Original 5/16 BSF round tee nut for seat rails.
Center = Two rectangular 1/4" BSF tee nuts - driver side, front.
Bottom = One round and one rectangular 1/4" BSF tee nut passenger side, front,

Lonnie
TF7211


LM Cook

If you want to make your own, here is how I did mine.
Top left frame gives dimensions.
Top right are the parts. Note that there are also little pins thst are supposed to lock the nut from turning, in addition to the nails.

Bottom left, Top side, original on left fabricated one on the right.

Bottom Right Bottom side, again original one on the Left.

I silver BRAZED the parts together.
Flange was 303, body was 304 tubing. I did have trouble threading the tubing. Even with a new tap. If I were to make them over I would use 303 rod.


JA Benjamin

It were always my understanding that the TF used wood screws (original from factory) like the other t-types did to hold the seat hardware to floor wood. Same understanding that near all replacement floor wood were/are sold with nut-serts, either the kind with spikes or holes for tacks.

Even MGA Guru thinks nobody really knows for sure on the later MGA's. I really like the spiked kind pictured in the Guru article at bottom. Interesting reading, might be of relevance for TF people. Looks like these inserts started getting used by MG factory sometime during MGA production. Maybe?
http://mgaguru.com/mgtech/frame/fr111b.htm


My question is that though these inserts are with no question bettter than wood screws, is there really any expert or factory proof they were used here by the factory? Or is that just what people figure because thats what they found in their "original" TF with replacement BMC floor wood from 1965?

JA Benjamin, those are nice. Good advice about stainless. It "can" be really hard to cut or drill, etc.
S Cole

S Cole
I purchased my TD in 1966 only 14 years after manufacturer.
Even then the floor boards were so decrepit I believe they had to be original.
They had captive or T-Nuts.
I did not replace the floor boards. I "repaired" them. Only the front 1/3 was bad. I grafted new fronts on.
The plywood is 3/8. I do not believe wood screws would hold a seat anchored only in 3/8 wood.
There is no evidence of any backer wood below the seats.

Jim B.
JA Benjamin

Jim -

Those are beautiful. I admire your creativity and craftsmanship.

Lonnie
TF7211
LM Cook

Thank you Lonnie, also S Cole.
Jim B
JA Benjamin

Original TD floor showing T nuts securing the seat as Jim suggests. Wood screws were definitely NOT original. Cheers
Peter TD 5801


P Hehir

T nuts were also use to secure the sliding cover for the brake master cylinder on the TD. See pic. Cheers
Peter TD 5801


P Hehir

"My question is that though these inserts are with no question better than wood screws, is there really any expert or factory proof they were used here by the factory?" Positively they were used at the front of the seat slide on TDs ant TFs, and I think at least one other near the pedal box or tranny cover on LHD cars. There is no proof that the sun will rise in the morning either...
George
George Butz

Well, now I know what these T nuts look like it would appear that I have found one in a plastic bag that was in the glove box. I need to get the clutch bled on my B today, and since it is currently up on my axle stands I will then get the TD up on the stands and see what else I can find. I do believe that my car has its original floorboard, it will be interesting to see what I find when I can really get to it.

This has turned into a rather fascinating discussion with some incredible insight and solutions put forth. Thankyou all for your contribution. I most certainly have a way forwards now.
S Griffin

George B,

I enjoyed your comments ! Of course,originally all TFs had the T nuts(5/16", BSF) affixing the front of the seat runner 'hinges' to the floorboards.The rear of the runners were held down by purile woodscrews into the floorboard ie. the seats originally did not tilt forward.

Peter H. is correct also in that two(2) (3/16", BSF ?) T nuts affixed the
master cylinder plate cover to the floorboard on rhd vehicles.

Cheers
Rob Grantham
Rob Grantham

There is an advantage of being able to tip the seats up in our climate here. I have been caught in torrential rains a few times and it is great to tip the seat up to let stuff dry out! Just curious what was used on LHD very early TD's with the MC cover plate? George
George Butz


"My question is that though these inserts are with no question better than wood screws, is there really any expert or factory proof they were used here by the factory?" Positively they were used at the front of the seat slide on TDs ant TFs, and I think at least one other near the pedal box or tranny cover on LHD cars. There is no proof that the sun will rise in the morning either...
George

Thing is Geo the MG factory was always "run" by a bunch of bean-counters. I'm sure they thought so anyway. Disputes today on originality for the post war t-types and through the MGA production can usually be settled by factory documents. "Service parts lists" and the like, even for floor woods that were probably made up by an outside vendor, will specify exactly how many and what sort of nut, screw, washer, tee-nut and brass tacks were involved in each floor piece. You know, proof. Have not seen any of that yet. Nothing beats a factory list.

P Hehrir shows some old boards and says they are original. How does he know they are original, and (if indeed orig.) were not modified with tee nuts when wood screws no workie no more? How can the validity of these assertions be determined without some explanation of why he thinks they are original and unmodified?

Rob G says with a sure attitude it was wood screws and tee nuts. Where is this certainty come from?
S Cole

Its simple,I have stripped out seven(7) TFs with the original floorboards and ALL had the T nuts in the same position as described. Some had the wood screws in position at the rear also with others having the screw hole left over.

Cheers
Rob Grantham
TF3719("Aramis"),TF9177("Athos").
Rob Grantham

Some had wood screws? Now were you working at a Brit car accident repair shop when these cars were "new" so you could be so sure the floorsboards were new? Were these 7 cars over the last 20 years, 5 years? I have seen t-types that needed new floors when they were 5 years old. Could the floors you stripped out have been aftermarket replacements? Were the t-nuts identical? Or have you some authoritative restoration reference book you can share the title of that discusses this, or the factory Service Parts List no. or know where to find a copy of the actual SPL for the boards? The main cause of erroneous restorations (not actually to original spec) over the years on these cars seems to stem from either replacement parts that became standardized wrong over the years or based on "original" cars that really were not. No SPL's on TF's?
S Cole

Thanks Rob. I also have seen about the same number of original TD floorboards that were removed from cars & stored in the fifties & sixties when they were being parted out after a prang. The pics I attached are of an original floor. I also know of at least two cars here that still have their original floors, both with T nuts. Absolutely no doubt about the T nuts being original. I also have purchased a set of 4 x 5/16" BSF T nuts from either Abingdon or FTFU a few years ago, I can't remember which. Again these were sold as original components. Hopefully that now settles that.. Cheers
Peter TD 5801
P Hehir

There are two possible postulates. The T-nuts are factory.
The T-Nuts are replacements.

Let's assume, for a moment, that the floor boards that Rob has seen had screws replaced with T-nuts. Also that both Peters and mine and many more in the US were replaced.

Our cars are separated by 10000 miles.
How did exactly the same BSF -5/16 T-Nuts get affixed in exactly the same way with bent and clipped nails.
In those days, when authenthicity was not paramount a US user would use UNC T-Nuts.

Occams Razor requires one to choose the simpler explanation. They came from the factory that way.

Jim B
JA Benjamin

Page 40 of the Drivers Handbook (TD) and Operation Manual (TF) both show an illustration for universal joint lubrication which just happens to capture an image of one of the T nuts for the left seat.

Matthew.
M Magilton


Let me explain how it really was. I was there.
There was only just one replacement floor maker back then, selling to US, Europe, AUS etc. to British Motors. Back then more people knew about the real world advantages of having BSF threads in a car like the MG. Practically a genuine self locking thread form. It was a sales gimmick to get people to buy. The "better than original" "new and improved" self locking BSF nutsert pre-installed in the improved rot resistant new plywood--to hold your seat where it should be. People loved the idea-- what with rumors flying about people crashing their new TF's simply because those wood screws were no good and coming loose, causing mayhem on the roads, and those crashes were from cheapskates who didn't want to spend a few bucks. Economy of scale and all, and "British" threads of course sounded right. BSF all around. No mystery, just how they made them all for the whole world around. Only mystery was why they kept crashing all those newish TF's like P Herir saw all the time with the new replacements with BSF nutserts? Same story on the bent and clipped tacks, It is just how all the replacements were done up. Simple. Since there were very few do-it-yourselfers back then when for car stuff, and besides you could just go buy new ones for the price of a couple of gin cocktails at the local bar. Everybody just bought the floor kits from their friendly parts counter man they were getting to know real good at their nearest British motors. My uncle Lovell worked the parts counter on weekends at BMC in Chicago (stock exchange boys liked those TF's). So a fella would go pick up a tune up kit and wires for his first tune up on the 6 month old TF and guess what? A special deal on replacement floors complete with all the "fancy" BSF hardware installed or included. "Good customer discount" and all, he liked to make any customer feel like one of the family to get him to buy more stuff. "Wouldn't want YOU to crash your car! He would say "they wont last long," and "those screws will be working loose any time now." When a tightwad would come in and not want to buy the floor kits he would say something like "guess your life insurance is all paid up this month." He got some people to buy new floors every year with "don't you notice the fresh pine scent has faded?" During the summer I would earn extra cash with Lovell. He would tell parts counter customers about how I was one of the youngest Engineering full professor's at McCormick at Northwestern. Actually I was the youngest, not one of the youngest full professors. It was fun spending time with Lovell getting people to buy stuff they didn't need. He would tell them how I was designing "nukular rockets" for the Army or something and how about I go out and take a look at their car and see if I can spot any maintenance items they needed? We sold a lot of steering and suspension components with my "inspections" because they really needed them replaced. Not sure what people were driving over to wear stuff out so fast, but they were. Not to mention all the gold seal engines when people would plead with Lovell to let them take me for a ride to see if I can hear that engine noise. I usually could.
'
S Cole

Pretty convincing Matthew. Thanks mate. About the only other thing I could add is that there are none so deaf... Cheers
Peter TD 5801
P Hehir

Sheet 33 of 35, MG-TD Specifications Book dated 1951 (this is a copy of an original book, so the Russians didn't hack it...): FS.105-6 Set Screw, Hex.Head. 3/4"x5/16" BSF No. OFF- 4, Seat slides to Floor. Sheet No. 24/3 PW105.Z516 5/16"x5/8" x.072" Plain Washer No. Off 4, Seat runner bolts. Somewhere else there is a spec for a bunch of 5/16ths T-nuts listed as used in many places (some round, some T-shaped). Of course this raised the question- if 4 were used, then you couldn't tip the seat base up, so why were they hinged?? George
George Butz

George, wouldn't four just indicate one at the front of each of the four seat runners? Bud
Bud Krueger

Since there were very few do-it-yourselfers back then when for car stuff, and besides you could just go buy new ones for the price of a couple of gin cocktails at the local bar.


WRONG!

In those post depression days everyone was a "Shade Tree" mechanic.

I was there also.

Jim B.
JA Benjamin

Bud, I was thinking of just one seat for some reason! George
George Butz

Well, Interesting to read so much discussion about a topic. I seldom come to the BBS now as there is usually enough people responding with the correct information.

However my factory assembly sheets do not show the 4 seat runner Tee nuts as they describe the floors both LHD and RHD as "supplied by Bodies Branch".

The build sheets do describe the other Tee Nuts in the floors. I copy as listed.

93280 Oblong Tee Nut 1/4" BSF 3 floorboard, 4 rear platform battens.

105518 Round Tee Nut 2BA 2 floorboard inspection plate RHD.

FS.105-6 Set Screw Hex head 3/4" x 5/16" BSF 4 off seat slides floor.
I have not listed the washers as these are self explanatory.
(NB no nuts are listed for these bolts so we must assume the nuts are in the ply from bodies Branch.)

The inspection cover plate screws are,
236D/1 no2 BA x 5/16" RD HD screw 2 off.

I have completed 30 TF restorations and 10 TDs, since 1969, almost all had their original floor boards and all had Tee Nuts. ( "Tee Nut" being the factory term used)

If the factory used Tee nuts to secure the steel cover plate that has no support requirement and also used Oblong Tee Nuts to hold the diff inspection ply section that also is not supporting anything like the weight of seats and people on seat slides, it would be senseless and not good practice for the factory to secure the front of the seat slides with only wood screws.

The MGA also used Tee Nuts to hold down the seat slides 8 in total. We have restored a number of MGA's also.

I think 40 T types is a good enough sampling of vehicles to confirm TD/TF had 4 "Tee Nuts" at the front holding the seat slides originally. I have been there since 1969.


Rod Brayshaw

Thank you Rod. I have an original pair of floor boards on loan (see pics above) & am yet to determine the size of the MC cover Tee Nuts. I do have a box of brass 2BA screws & a 2BA tap which I'll now use to confirm the size you've posted. I fully expect to find that they are indeed 2BA. I totally agree with your comment that "it would be senseless and not good practice for the factory to secure the front of the seat slides with only wood screws." The Brits had a habit of over-engineering everything so the suggestion that securing the seats with just a couple of wood screws made no sense to me at all. Cheers
Peter (Hehir) TD 5801
P Hehir

The above info. just confirms what we knew to be the original fixing
method for the seat slides,5/16" BSF set screws into Tee Nuts. There were/are two(2) per seat.

I have been rebuilding/restoring TFs for only 41 years whereas Rod B has been at it for 48 years !!

Happy and informative New Year 2017.

Cheers
Rob Grantham
TF3719("Aramis"),T9177("Athos").
Rob Grantham

Pic shows one of the two MC cover Tee Nuts in an original floorboard with a 2 BA screw partially inserted thus confirming Rod's advice. This answers one of my questions on the flooring detail & is another example of Abingdon's mixed use of both BSF & BA threads in the T types. Also thanks to Simon for initiating this thread. Cheers
Peter TD 5801


P Hehir

Peter,

I just love it!

Cheers
Rob Grantham
Rob Grantham

Seemed like an innocent enough question! Stunned by the depth of discussion. Thanks everyone and Happy New Year!
S Griffin


I never thought much about how the seat runners were secured in TF's and TD's. Sounds like T-nuts. The TC seat bottoms fit so precisely between the tub and the differential cover that each seat runner was secured entirely by three wood screws through the front part of the runner hinge (into the wood floor). 12 screws total both seat bottoms/4 runners. Nothing else. Remove the seat back and you can flip the seat bases up/forward. Installed, the seat back does not allow the seat bottoms to lift. Sounds like they are really bolted down in the TD/TF.

Not a single T-nut was originally used anywhere on a TC. The floors were held down with special bolts and captive nuts welded to the chassis.

So, it sounds like MG began using T-nuts in the TD.




D mckellar

George Butz
Way up above, you show a photo of NEW T nuts. Where do you get those new, today?

Tom
'54 TF
T Norby

Tom, Ebay has lots. "Tee nuts" is a good search term. Some 3 and some 4 prong. Or the kind with the little holes for brass nails, on ebay try "screw on tee nuts"
D mckellar

Frank Cronin (USA) took some very useful photos of the fairly original
TF9052. The car has only done around 5,700 mils in total and is still
owned by the person who bought it from new ! Google 'The Original mgtf midget',then go into the site and look under Gallery,
TF9052.

Under the heading of 'Interior Pictures',Image 304 depicts the
setscrew holding down the front of the seat runner. Could be a 'Sparts' brand .

Also,if you look at the section 'Chassis and Underside',there are images of both the oblong Tee Nuts and round Tee Nuts,images
208,235,169,155 and 153.

Image no.174 in the 'Chassis and Undersid' section, is interesting.
You can just see a pair of woodscrews 'peeping' through the ply which hold down the REAR of the TF seat runner !

Went up to the Garage loft,and dragged down two(2) sets of black and greasy TF original floorboards. Looked for evidence of two(2) holes that were used to hold down the REAR only of each seat runner,and there they were, two(2) woodscrew holes per runner at the rear in the same position as TF9052 i.e. a total four(4) woodscrews per seat. This was evident in both sets of my original floorboards.

As previously stated,each TF seat was/are affixed at the front via 5/16" BSF setscrews and most likely four(4) woodscrews at the REAR.

Cheers
Rob Grantham
TF3719("Arams"),TF9177("Athos").
Rob Grantham

Interesting! So what is the point of having the hinge in the front if the bottom of the tracks are screwed down? Or am I missing something? Tom, I just Googled for pictures, no clue where to get them. The spiked kind are at big box stores also. George
George Butz

Tom -

(Posted previously in thread)

All modern tee nuts that I have seen are course thread SAE or Metric.

> SIMILAR TO ORIGINAL TEE NUTS
McMaster-Carr has round unplated steel 1/4-20 and 5/16-18 brad hole "Screw-Mount" course-thread tee nuts that have three holes for tacks and have three cones that press into the plywood, similar to the original round tee nuts. The threaded section on the 1/4-20 tee nut may need to be shortened.
http://www.mcmaster.com
1/4-20 = #90611A600
5/16-18 = #90611A610

> SIMILAR TO TEE NUT PHOTO BY GEORGE BUTZ
1/4-20 and 5/16-18 stainless steel brad hole tee nuts without cones are available at Lowes and Home Depot.
http://www.lowes.com/pd/The-Hillman-Group-1-4-in-Stainless-Steel-Standard-SAE-Brad-Hole-Tee-Nut/3025380
http://www.lowes.com/pd/The-Hillman-Group-5-16-in-Stainless-Steel-Standard-SAE-Brad-Hole-Tee-Nut/3025381

Lonnie
TF7211
LM Cook

Thanks guys
Would any of you have ONE original tee nut with BSF threads for my TF seats? Does not need to be pretty, just usable threads.
Much appreciated.

Tom
'54 TF
T Norby

Yes Tom;
I can supply an original, or one of my repros.

Jim B.

mgtd51-at-verizon-don-net
JA Benjamin

How in the world did a "thread" (pun intended) on T-Nuts get to 92 posts? :-)
Christopher Couper

Am I wrong thinking that Mr. Cole is just having a little fun with this thread?
J K Barter

Seems that most of the posts have been duplicated Chris. Not sure how or why. Cheers
Peter TD 5801
P Hehir

George B,

Yes,a question I have also pondered. No smart answer as yet.

Tom N.,I noticed my original floorboards have three(3) out of four of the original 5/16"T Nuts still in the front seat runner position,
however it looks like Jim has already responded to your request.

JK Barter,believe me this Thread has certainly been 'a little fun for everyone' !!!

Cheers
Rob Grantham
TF3719("Aramis"),TF9177("Athos").
Rob Grantham

George B.,

Do TD seat runners also have hinges at the front ? If so,the TF hinged seat runner may be the same as the TD ? Some features on the cars
were left in place through expediency although not subsequently used.
For example,the small 'L' type bracket located on the Side Engine Plate for TFs,is not used. It was used on earlier MGs however.

Cheers
Rob Grantham
Rob Grantham

I wonder if other marques in the Morris group used the same runners?

Matthew.
M Magilton

Could the runners have been screwed down in the rear just to keep the seats from moving during shipping?
J K Barter

Sorry if this is repeat. Didn't see it yet.
Looks like a 5/16" BSF T-Nut dead ringer. Maybe not really round? Available here:

http://www.mgbits.com/contents/en-uk/p3824_T-Nut-Round_5_16__BSF.html


D mckellar

D mck.,

A good find with the NTG TF front seat 5/16" BSF T Nuts. With respect to a 'previous query' re the original T Nuts being identical, as you have gleaned the NTG variety differ from the originals in that the bases of the originals were round and in fact 7/8" in diameter ! (lol).

JKB., A possible reason for the rear TF runner screws.

Cheers
Rob Grantham
TF3719("Aramis"),TF9177("Athos"').
Rob Grantham

Rob, yes, hinges at front. It has been a while since I have removed my seats. However, I think the back of the seat bases (TD) and entire TF seats have to be tipped up, then slid backwards and up to remove. If the track was screwed down, how would you remove/install the seat/bottom? Maybe just designed to slide the base/seat forward and remove screws at the rear, then tip up? George
George Butz

B&G sell the same tee nuts as NGT, and no they aren't the same as the originals.
Dave H
Dave Hill

Hi George,

You are right,the only way to tilt the TF whole seat forward,would be to remove the rear woodscrews. I really can't see a reason to do this
unless one wanted to clean/vacuum under the seat !

Cheers
Rob Grantham
Rob Grantham

Yes, Rob, the TD seat runners are hinged at the front through T-nuts (only floorboard connection). Bud
Bud Krueger

Here is the little chap I found in the glove compartment.


S Griffin

George B.,

I have wood screwed down the current TF seats at the rear.

The whole seat is placed in the car, setscrewed(2) into the front 5/16" T nuts, then by moving the seat forward on its runners/slides,one can
put in the four(4) woodscrews at the rear. Done !

Rob Grantham
TF3719("Aramis"),TF9177("Athos").
Rob Grantham

This thread was discussed between 28/12/2016 and 06/01/2017

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