MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

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 MGA - Glass and Broken Glass...

When I drive my MGA 1500 roadster up to 58 MPH the wheels and tires drift over the road as though it is glass. I am running Pirelli P1500 which are in good condition. The resonance is smooth, the tires straight, and the whirring of car through air is wistful. As soon as I hit 59 MPH (or close to 60, as it were), things feel as though the smooth glass has shatterd and broken, with a vibration in the wheel back a forth in short fitful motions, a chattering noise which interrupts the music of this old English machine down the road. (I admit I do not have the felts installed on the steering shaft, if this matters). The wheels still seem to be running straight down the road, but this fit of temper cannot be stilled again until I throttle up to around 64 MPH, at which time some sympathetic vibration takes over again and I once again experience the sensation of driving over a sheet of glass...smooth and serene. So, any thoughts on what's going on with the poetry of this odd machine?? Is it the steering rack? Is it the wire wheels which need tuning?

Steve
Stephen Lofaro

Hi Steve,
I had the same problem between 50-55 m.p.h. You could check that the wheels have been balanced correctly however even new wire wheels do not usually stay true for long and that is usually the problem. I converted my hubs to bolt on wheels and fitted minilites, problem solved and handling improved as the rims were not flexing on the spokes.

Ian.
I Hazeldine

Also check the shock oil on your front shocks.

Dennis, Arizona
rtoys

I have been investigating the balancing of MGA style wire wheels in the UK. Most tyre shops say they can balance them no problem. The reality is that it is very difficult to properly centralise the MGA wheel hub with its chamfered shoulder on balancing machines. I had my wheels balanced a few weeks ago, but I am very disappointed with the result and my wheels remain much as described in the opening post, although my vibration is 65-70mph.

Bob West claims to have solved the problem. He has accurately mounted an MGA/Healey splined shaft on his balancing machine. Apparently most Healey and MGA owners in Northern England take their wheels to him to get the job done properly. He reports that many wheels that have been balanced by tyres shops are shown to be way out when he puts them on his machine.

Steve
Steve Gyles

These folks are real good.

http://www.hendrixwirewheel.com/

Regards,
Christopher
Christopher Wilson

If you can, find a garage that still has one of the old Stewart Warner on the car balancers. The wheel gets balanced as well as anything rotating with it like hubs, brake drums, etc.
J Heisenfeldt

Probably a wheel balance problem, but what tire pressures are you running? There is a tendency to put too high tire pressures on the MGA, especially in North America where most modern vehicles run 32 - 36 psi. Try 24 front and 26 rear. Steering may be a bit heavier at low speeds, but the comfort is greatly improved.
Peter.
P. Tilbury

That's an interesting observation Peter. I have been running 27 all round for as long as I can remember. Should I have lower at the front? If so, what is the reason?

As an aside, I use a 14 inch steering wheel, so it's already very heavy at low speed (parking etc) - I am currently on quartizone injections in the right shoulder because of wrenched tendons (my diagnosis), partly due I suspect to the heavy steering and the cold weather on my body during this cold winter! I guess it's the price I am paying for driving topless all winter - car, not me!

Incidently, my Haynes MGA manual specifies 5.60 x 15 tyres for for all MGA models except for Dunlop disc brake cars which should use 5.90 x 15. Why is this?

Lots of questions, I hope some of them are relevant to this thread.

Steve
Steve Gyles

Steve,

The use of the 5.90 tyres for the Twin Cam was just a normal increase for a car with 50% more power.
The Deluxe pushrod car had the 5.90 instead of the normal 5.60 because that was the size that Dunlop had already supplied to MG (or was on firm order) prior to cancellation of the Twin Cam.


Mick
M F Anderson

Mick

If it's a power question, then those of us with the 1800 could consider this as an option?

Steve
Steve Gyles

Steve, put the bigger steering wheel back on and grease your front suspension and oil the rack and column bushes, lol!
Neil McGurk

Steve,

For a quick experiment, switch the front and rear tires to see what happens. My bet is with the majority. I think your tires are out of balance.

Peter
PC Cirillo

Hi Steve,
You will have seen the recommended tyre pressures in the general data of the workshop manual. These are, of course, for crossply tyres so need to be adjusted up somewhat for radials. Note that front and rear vary by 3 psi for each situation.
27 on front will make the car a little skittish in high speed corners, but not a significant difference from 24 psi. However, 34 psi would be a huge over inflation, reducing the tyre flexibility (and hence comfort) and reducing the tyre footprint. Very scary in wet weather!
We have toured thousands of miles in NA with 24/26 psi, and found these settings to work well for us.
Peter.
P. Tilbury

Steve Gyles,

Neil is right; put the big steering wheel back on. I'm running 195 65 tires on my 1800-powered A and it steers easily. (I've also had both shoulders repaired, but that damage was probably from my TR6!)

Ken
k v morton

Ken and others

Nah. Love my smaller wheel, worth the pain! I was converted to the concept of the smaller steering wheel after Barry gannon let me drive his old faithful white car back in 1999. The heavy steering at parking speeds is the only minus point. At normal operating speeds you get a wonderful feel of the car, far better than with the big wheel. Don't knock it until you have tried it.

Anyway, sold the big wheel which was a modern wood rimmed version.

Steve
Steve Gyles

I can recommend a great orthopedic surgeon for your shoulder!

Ken
k v morton

Ken

I already have one who is very good at taking gundge out of a spine disc!!

Where are you Barry Gannon? Support me on small wheels!

Cheers

Steve
Steve Gyles

Steve, not to be overlooked is the drive shaft UJ's.
I had one that had a bearing failure which at first was probably giving only a slight vibration, by the time I got to it the bearing shaft looked like it had been chewed in a vice. Replacing with new stopped all the vibration.

Neil
Neil Purves

Had my wheels balanced at Bob West's. They were way out of balance when James put them on their adapted balancer. I had been assured just over 2 months ago by a local tyre shop that it was no problem balancing MGA wire wheels - and I let them do it.

James explained that most tyre shops place cones on the spindle shaft to hold the wire wheels. In the case of the MGA-design wheel, the contact points on the hubs with the cones are not perfectly round, hence errors are built in. The only way to guarantee perfect balancing is to adapt the balancing machine as shown in the image.

Steve


Steve Gyles

Fitted the wheels back on this morning and did a test run. Totally amazing. The car has never been so vibration free up to 90mph. It's been pretty good in the distant past when the wheels were balanced while on the car - no one seems to have one of those machines now, but they have never been as good as now.

I thoroughly recommend any wire-wheel MGA owner who can drive to Bob West to have them done on his machine. Outstanding.

Steve
Steve Gyles

This got a lively response...ty all. I think I should start by rotating my tires and checking pressures and see how the vibration goes. I will also begin checking for a good wire wheel balancing shop in the southern California area. I had a tech check my car and I need new steering rack boots. I am considering installing a new rack as they have recently become available for MGA. Please see my post regarding rack and pinion as I have some things to sort through and looking for experienced feeback.
Best,
Steve L.
Stephen Lofaro

Steve, I am not sure if Barry is off again in his campervan but I will support you - I have a 14" Moto-Lita. I love it - easier to get into the car, no problem with steering - great for motorkhanas!



Mike Ellsmore (1)

Mike

I think he has been out in the bush quite a bit. He also seems to be having IT problems from time to time. I like the Australian Reister grill badge. It was good of them to make them in our car colours, even down to the trim - Barry sent me one.

Steve
Steve Gyles

Steve, thats a great wire wheel adapter in your photo! And quite logical when you think about it. Anybody in Melbourne, Australia got one of these? My TF has the (MGA) wire wheels.

Cheers,
Matthew.
Matthew Magilton

This thread was discussed between 09/03/2009 and 22/03/2009

MG MGA index

This thread is from the archive. The Live MG MGA BBS is active now.