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MG MGB Technical - MGB sits higher than a 4x4

I recently bought an unfinished project 1976 MGB GT, the previous owner has fitted all new springs, bushes etc all round. At the moment the car sits ridiculously high.
Measuring through the centre of the wheel to edge of the wheel arch the rear sits 28" high and the front sits 28.75" high. My other B GT which has been lowered 1" from rubber bumper height sits 22.75" high at the back and 24.5" at the front measuring from the same positions.
The extra height is so bad it has stretched both axle straps until they've snapped and on the ramp the axle drops so low I can't possibly fit the exhaust.

Is it possible that the car has been fitted with the wrong springs?

It has not been driven to settle the springs but has the full weight of the engine and gearbox in the car.

Attached is the best picture I have that shows the height of the car

Thanks
Kieren


K Goldup

omg... got to be the wrong/faulty springs
Brian Shaw

On the rear - do the shackles face backwards - i.e to allow the springs to settle when compressed.
richard boobier

That is ridiculous. Difficult to understand how anyone can fit the wrong front springs...............but not impossible!!. Possible that everything on the front suspension was torqued up with the wheels hanging and the friction is holding the front up. Puck a jack under the spring pans and slacken the fulcrum pins etc., then do them up again, see it that at least settles the front a bit, if not take a spring out and measure it's free height , should be about 9.5", give or take. Also check that the coils are sitting fully in the spring pan and properly located around the x member locating boss. The rears are more problematic. I suppose it's possible that the shackles are too long or that the spring hangers have been badly welded in, but more likely over curved or under tempered springs.
Allan Reeling

The front looks a little tall - are they 70 profile tyres ? The rear is quite a bit higher than I would expect and so far as I can see the springs have not yet adapted to the weight of the car. Allan's advice aside,I would like to see the car with its bumpers fitted before the panic sets in. The (rubber)bumpers make a big difference.
Roger
Roger W

Has it got the engine and gearbox in? Don't laugh, I've twice in the past seen people asking the same question when they haven't.

I've also seen in the past that with new rears fitted a couple of Americans have been needed in the boot to compress them enough to get the straps fitted. Springs as over-arched or over hard as that seem to have been quite common there a while ago, and more recently here too. That might be because Abingdon only allowed 150lb i.e. 10st 10lb, maybe some manufacturers felt the need to beef them up a bit for modern occupants.

New rubber straps will almost certainly break under those conditions as they contain no reinforcing i.e. are little more than rubber bands, which is why reputable suppliers should have stopped selling them. Moss in the US has apparently obtained the correct ones, and have a jig to test them, don't know whether MOS Europe have them. I've had to fit parcel strapping round mine.

New springs will be high before any shake-down running, especially fronts in my experience. Whilst I've not had any problem with the rears being too high (on the contrary I've had to extend the shackles to stop bottoming and grounding on the 73 roadster when touring fully loaded (and before you ask the Navigator and I are within the Abingdon allowance ... just)) but a couple of sets of fronts have had a higher free height than spec. Newly fitted to the CB roadster I got 16" between the centre of the hub and the bottom of the trim-strip, even higher than that on the RB V8. The roadster lost 3/4" after a shake-down, the V8 over an inch, a couple of years later they both lost another 1/2"

Having changed rear springs several times on chrome bumper and rubber I've never had the claimed situation where the shackles lock up against the chassis rails. Jack up under the springs until you can get the shackles inserted, then keep jacking and they angle downwards as they should.
PaulH Solihull

Yes the car has the engine and gearbox in and since that picture the rear bumper has been fitted (this was before I measured the heights).

I will have a look at the hangers etc tomorrow, will try jacking it under the axle with some extra weight in the back and slacken off all of the bolts then re tighten them to see if it makes a difference. I'll also try the front.

I'm also unsure of the tyres sizes at this moment in time although that is not the issues looking at the gaps between the wheels and the arches.

Absolute worst case I'll get my self a set of lowering springs for the front and a set of chrome bumper springs for the back as it will need lowering eventually as the standard rubber bumper height is excessive at best.

Thanks
Kieren
K Goldup

Kieren,

If the rear shackles are the in the wrong direction it may be possible to pry bar over with load off or jack car / axle and repostion.

Had this problem with new springs whilst building up a midget and little weight to jack against at the time.

R.
richard boobier

"I'm also unsure of the tyres sizes"

Measuring the ride heights from the centre of the axles to the bottom of the trim strip removes all aspects of wheel and tyre from the equation ... unless you have a mix of Mini and monster truck wheels ...
PaulH Solihull

Well the hangers are pointing the wrong way it would seem but they do not want to swap positions!

I've cracked off all of the bolts, put as much weight in the back of the car as possible (170 litres of various fluids), tried jacking under one side of the axle and I'm trying to lever them.

So far one of them is pointing straight down but I can't get it round that bit more. Any ideas appreciated!
K Goldup

Turns out I needed a human on the rear bumper aswell as all the water!
Rear is much closer to where it should be now the hangers are pointing the right way.

Didn't have much chance to look at the front but the springs have red dots on them (with Porsches you can reference the springs by colour but not sure if its the same with MGs). Also with the suspension at full drop the springs measure at 9 inches (still slightly compressed) so at the moment I think they are the wrong ones.
I'll take them out to measure them when I get a chance.
K Goldup

Glad you sorted it - sometimes its just easier to take it apart and start again putting it back knowing it's correct !

I would check the front after a short run - mine was a bit high at the front to start.

R.
richard boobier

MGB springs have colour splashes as well, but I've not seen a list of what has what. I've had red splashes on what should be BHH1077 i.e. 72-on CB GT and all V8, 9.32" free height, but then they were higher than that off the shelf. You won't know the real ride height until you can settle them over some road humps, the fronts especially.
PaulH Solihull

Be careful if you change your front springs. Speaking from experience, the special short 'lowering' front springs may drop the front to the 'correct' (chrome bumper) height, but you will get bump steer and possibly bottoming out.

The rubber bumper cross-member will never allow you to get the same front ride height as a chrome bumper car without some sacrifice.

Have a read of Paul's site on this subject. I did, and replaced the special lowering springs on my 'chromed' '77 B with the longer chrome bumper ones. The front is now slightly higher than a c/b car, but I was happy to settle for that in exchange for a better ride, with no bump steer.

John Bilham

I'm fully aware of all the lowering issues as I lowered my other B a few years ago so have had all that fun already. I haven't tried it yet (as it will upset the tracking and our tracking ramp is occupied) but I reckon as I have 15" wheels I can turn the t-rod end the wrong way up bring it more in line with the rack reducing bump steer.


Any way back onto the 4x4, the front springs measure up at 10.5" off the car so maybe a nats too big
K Goldup

I'd have said that you can't just turn the track-rod ends the other way up as the pin on those and the hole in the steering arms is tapered. You *may* be able to swap the arms between sides, but unless the three holes are in line that will also have an effect on track-rod angle.
PaulH Solihull

10.5 inches is at least 1 inch too long, so there is part of the problem. At least the correct R/B front springs will get the same front end height as a chrome V8. My V8 conversion is on a R/B shell lowered to C/B height. I swapped the control arms over and have had no problem with bottoming or bump steer.
Allan Reeling

According to published sources 10.2" is the correct free height for the 72 and later CB roadster and the RB GT, part number BHH 1225 for the 73 and later CB roadster and RB GT, the 72 roadster having fewer free coils and a slightly lower loaded height. Whether the manufacturer of these now pays much more than lip-service to the original specs is debatable.
PaulH Solihull

My manual gives 2 different lengths for late model GT's 10.2 and 9.32, the shorter being the later.......................?????????? I give in. Whatever, if your headlights are illuminating the tree tops and the springs and suspension are seating properly, you need shorter springs!!!
Allan Reeling

The Parts Catalogue gives BHH 1077 9.32" free height for V8s and 72 and later CB GTs. For GTs before that it was AHH 5789 for the GT, for RB GTs and 72 and later roadsters it was BHH 1225 10.2". In fact the two (9.32" and 10.2") give very little difference in loaded height as the number of free coils and hardness also differ, the shorter springs give a firmer ride though, having had both on my 73 roadster.
PaulH Solihull

Very interesting Paul, thanks for that.
Allan Reeling

This thread was discussed between 27/12/2012 and 02/01/2013

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