Is this tyre bad enough to make my steering wheel wobble?
Discussion
Car is e36, ive replaced everything. Had it 4 wheel tracked and balanced, new discs, pads, lower arms,lower arm rear bushes, droplinks, the lot. Jacked car up after getting home and discs sound even (30 miles on them).
Car wobbles under braking from 80- 60. Both fronts are feathered down on insides but tyres still have 4mm+ to the markers apart from this.
So, are these tyres bad enough to cause wobble under braking?
I used to have an E36, and that wobbled sometimes too. Then again sometimes it didn't. Tyre fitter claimed it was a common BMW problem and that the proper procedure is to set the tracking with lasers (beyond most independent garages' capabilities). He said if that isn't done they can wobble. It could be rubbish.
Futuramic said:
I used to have an E36, and that wobbled sometimes too. Then again sometimes it didn't. Tyre fitter claimed it was a common BMW problem and that the proper procedure is to set the tracking with lasers (beyond most independent garages' capabilities). He said if that isn't done they can wobble. It could be rubbish.
It is a bit intermittent, had the tracking done by laser last time as well. It's starting to really piss me off, ive chucked a fortune at it.That is almost certainly suspension wear somewhere. The front wheels are going toe-out under brakes and the judder you feel is the oscillation of wheel/wheels going back-and-forth as a bush or component flexes when it shouldn't.
As it happens at higher speed, I would suspect something other than a rubber bush; check and double check all ball-joints and mounting points.
As it happens at higher speed, I would suspect something other than a rubber bush; check and double check all ball-joints and mounting points.
littleredrooster said:
That is almost certainly suspension wear somewhere. The front wheels are going toe-out under brakes and the judder you feel is the oscillation of wheel/wheels going back-and-forth as a bush or component flexes when it shouldn't.
As it happens at higher speed, I would suspect something other than a rubber bush; check and double check all ball-joints and mounting points.
Everything on the car has been replaced short of top mounts and they dont clunk or show play either.As it happens at higher speed, I would suspect something other than a rubber bush; check and double check all ball-joints and mounting points.
Could that tyre wear (which is the only thing left after replacing all bushes) be causing it though? That's the question now.
I'm in the process of scrapping an MR2 for a similar problem. It's had every inspection from a range of experts and everything replaced - still wobbles, intermittently, same as yours. I also threw a fortune at it.
Those tyres aren't great. If it were me I 'd swap them front / rear, jack the rear, axle stands then spin them at decent speed to see if they look warped. This Ian 't entirely hazard free if course, make sure you think the risks through!
It's also worth getting the tyres off. I found one full of rubber marbles one time. They were free to roll around and that can't have been helping.
Those tyres aren't great. If it were me I 'd swap them front / rear, jack the rear, axle stands then spin them at decent speed to see if they look warped. This Ian 't entirely hazard free if course, make sure you think the risks through!
It's also worth getting the tyres off. I found one full of rubber marbles one time. They were free to roll around and that can't have been helping.
Uniformity issue with your front tyres?
One possible reason that it varies in intensity is that a short term flat spot is cancelling some of the permanent force variation in your tyres.
No tyre is perfectly round, some generate high vibrational forces in rotation, when you brake you increase the transfer of these vibrational forces into your chassis (because you compress bushes more and they effectively become stiffer).
Go to a garage with road force balancing equipment. Ask them to check your front tyres for force variation, ask them for the raw data plots of the 1st, 2nd, 3rd harmonics. A bit of advice, you should not park for long before you take the tyres off the car, as even parking for 5 minutes can give unrepresentative results.
One possible reason that it varies in intensity is that a short term flat spot is cancelling some of the permanent force variation in your tyres.
No tyre is perfectly round, some generate high vibrational forces in rotation, when you brake you increase the transfer of these vibrational forces into your chassis (because you compress bushes more and they effectively become stiffer).
Go to a garage with road force balancing equipment. Ask them to check your front tyres for force variation, ask them for the raw data plots of the 1st, 2nd, 3rd harmonics. A bit of advice, you should not park for long before you take the tyres off the car, as even parking for 5 minutes can give unrepresentative results.
You need someone with a Hunter balancer with road force measurement in your area, and the guy needs to know how to use the thing. Ring Hunter in Towcester to find the machine, it is simply the best there is, but requires an intelligent operator to get the full story.
I have to assume that all the tyre wear occurred before you replaced all those parts? Either way with the greatest respect they might just be legal, but on a practical level they are scrap, so replace them during the test on the balancer to get a before and after. if the tyres are ok then try taking the speed off the car from 80 to 60 by other means than the front brakes, using engine braking etc. If the tyres have been proved to be ok, the brake pedal is not being used and the problem is not there, then the front brakes/suspension/wheel bearings are still the issue. You have to be methodical with your diagnosis, be prepared to pay a little, but allow no 'fitters' to diagnose, only credible people. Lastly only buy parts to diagnose when nothing else will do. That's what all my clients get at the Sports Car Shop
Peter.
I have to assume that all the tyre wear occurred before you replaced all those parts? Either way with the greatest respect they might just be legal, but on a practical level they are scrap, so replace them during the test on the balancer to get a before and after. if the tyres are ok then try taking the speed off the car from 80 to 60 by other means than the front brakes, using engine braking etc. If the tyres have been proved to be ok, the brake pedal is not being used and the problem is not there, then the front brakes/suspension/wheel bearings are still the issue. You have to be methodical with your diagnosis, be prepared to pay a little, but allow no 'fitters' to diagnose, only credible people. Lastly only buy parts to diagnose when nothing else will do. That's what all my clients get at the Sports Car Shop
Peter.
Check the toe is set to the correct settings, definitely not unknown for people to get that wrong.
I've had tyres as bad as that with no wheel wobble, so wouldn't expect it to be that.
You don't say whether the odd wear pattern occurred after or before your remedial measures?
Is the camber adjustable? Maybe that is out...
I've had tyres as bad as that with no wheel wobble, so wouldn't expect it to be that.
You don't say whether the odd wear pattern occurred after or before your remedial measures?
Is the camber adjustable? Maybe that is out...
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