Wobbly Wheel

Hi Guys,

I've been having fun with my motor recently... not the sort of fun we all want to have.  The miserable sort of fun trying to find the cause of something.  In this case - high speed steering wheel wobble.  Now the obvious and most common problem that causes this is wheel balancing but if you read on you will see I have covered that several times over.

Here is my story so far.

Roughly 2-2.5 months ago one of the rear trailing arm bushes broke through excessive wear.

While that was being fixed the mechanics found both rear shocks to be dead too.  I can't believe I didn't notice this as I'm normally pretty good with things like that but hey ho - on we go.

When I got the car back I found it to be pulling heavily to the right hand side.  I put this down to geometry settings being out due to all the work which had just been performed on the car.

I took the car to horizon motorsport who did a geo upgrade and alignment for me.  They were very very helpful and re-adjusted the car several times after as I didn't feel comfy with the upgraded geo. 

One of the final things they did for me was install some polyurethane bushes on the front trailing arms as I was feeling some looseness with the front end at speed.

After this I first had the wheel wobble.  I had all four wheels balanced and these seemed to ease the problem but not cure it.

My mechanic had noticed on a previous visit that the lower ball joints on the front arms were worn.  He said it wasn't a major issue but could do with being seen to in the near future.  I figured that because I was probably feeling more through the steering due to the new bushes I was probably feeling the play in the arms at high speed.

So I had those changed.

Still got the wheel wobble after this so I had the wheels checked again by a different garage.  This time I was told both rear tyres were due for replacement and one of the fronts.   I was also told the wheels were out of balance again which I found suprising considering I'd only had it done about a month before.  Still.. I had them do it.

Still had the wobble.

Had the garage put the rear wheels on the front and the fronts on the back.  Just in case the front tyres being so old (almost three years) might have been out of shape.  Aside from some strange pulling to the right (the rear tyres had been worn alot on the inside - I put this down to the natural wear pattern of rear tyres on a bimmer) the wobble was gone. 

Yay I thought.  That's the answer.

So I ordered 4 brand new Continentals.

Had them fitted.

Wheel wobble back.  :(

Had the front and rears swapped again after a couple of days.

Wheel wobble still in effect.

Now I had a couple of theories.

One theory being one of my alloys could be out of shape - when the guys were fitting the new tyres they took all the wheels off the car... so if by my previous swapping of wheels I'd managed to get the bad one put to the back - it might have made it back to the front.

I also know that some garages don't always balance the rear wheels.  So if I'd had the wheels swapped and the bad wheel ended up at the back I could have ended up with an unbalanced wheel at the front.

This is the only explanation I can come up with - I haven't got round to taking the car back to anywhere yet.  Hoping to do that the weekend but in the meantime.. does anyone have any other ideas????

BTW the speeds I get the wobble between are 55-80ish...

Any ideas on what this could be would be most most most welcome.

Thanks

Gaz

Pegsta wrote: Hi Guys, I've been having fun with my motor recently... not the sort of fun we all want to have.  The miserable sort of fun trying to find the cause of something.  In this case - high speed steering wheel wobble.  Now the obvious and most common problem that causes this is wheel balancing but if you read on you will see I have covered that several times over. Here is my story so far. Roughly 2-2.5 months ago one of the rear trailing arm bushes broke through excessive wear. While that was being fixed the mechanics found both rear shocks to be dead too.  I can't believe I didn't notice this as I'm normally pretty good with things like that but hey ho - on we go. When I got the car back I found it to be pulling heavily to the right hand side.  I put this down to geometry settings being out due to all the work which had just been performed on the car. I took the car to horizon motorsport who did a geo upgrade and alignment for me.  They were very very helpful and re-adjusted the car several times after as I didn't feel comfy with the upgraded geo.  One of the final things they did for me was install some polyurethane bushes on the front trailing arms as I was feeling some looseness with the front end at speed. After this I first had the wheel wobble.  I had all four wheels balanced and these seemed to ease the problem but not cure it. My mechanic had noticed on a previous visit that the lower ball joints on the front arms were worn.  He said it wasn't a major issue but could do with being seen to in the near future.  I figured that because I was probably feeling more through the steering due to the new bushes I was probably feeling the play in the arms at high speed. So I had those changed. Still got the wheel wobble after this so I had the wheels checked again by a different garage.  This time I was told both rear tyres were due for replacement and one of the fronts.   I was also told the wheels were out of balance again which I found suprising considering I'd only had it done about a month before.  Still.. I had them do it. Still had the wobble. Had the garage put the rear wheels on the front and the fronts on the back.  Just in case the front tyres being so old (almost three years) might have been out of shape.  Aside from some strange pulling to the right (the rear tyres had been worn alot on the inside - I put this down to the natural wear pattern of rear tyres on a bimmer) the wobble was gone.  Yay I thought.  That's the answer. So I ordered 4 brand new Continentals. Had them fitted. Wheel wobble back.  :( Had the front and rears swapped again after a couple of days. Wheel wobble still in effect. Now I had a couple of theories. One theory being one of my alloys could be out of shape - when the guys were fitting the new tyres they took all the wheels off the car... so if by my previous swapping of wheels I'd managed to get the bad one put to the back - it might have made it back to the front. I also know that some garages don't always balance the rear wheels.  So if I'd had the wheels swapped and the bad wheel ended up at the back I could have ended up with an unbalanced wheel at the front. This is the only explanation I can come up with - I haven't got round to taking the car back to anywhere yet.  Hoping to do that the weekend but in the meantime.. does anyone have any other ideas???? BTW the speeds I get the wobble between are 55-80ish... Any ideas on what this could be would be most most most welcome. Thanks Gaz

Hi there Pegsta

Interesting post - one of the things I noticed was that you have had poly lower control arm bushes fitted as well as a lot of suspension work.

Now, applying logic to your problems, it would seem that you have (prior to fitting your Continentals) achieved a wobble free ride with your current suspension set-up when your mechanic swapped your fronts to the back? Correct?

That says to me that it is the wheels/tyres that are now causing your wheel vibrations rather than anything else worn on your car.If it was something on your suspension,  balancing the tyres/wheels would not have removed the wobble unless you had them balanced on the car and by consequence the  erroneous suspension part had been balanced as part of the whole rotating assembly. 

I think the relevance of the poly bushes is that it makes the car very sensitive to slight imbalances in the wheel/tyre combo.

Have a look at this post off E36coupe and see whether you might think it worthwhile trying a balance of your wheels on a Hunter Road Force machine

This is the post 

****************************************************

The importance of a good wheel balance...

Apologies for length, I want you to feel my pain!

Recently I fitted Bilstein Sprintlines all round, along with new wishbones and Powerflex bushes, for good measure I changed the top mounts too.

The car had no wheel balance issue before hand but after I had a quite violent shake / shudder at 65-85mph.

I had them balanced locally and the problem was the same, I watched the guy get them to '0' too.

I knew I needed alignment but I didn't think it would cause a wobble like this. I wanted to hold off until any other possible part of the car requiring 'refreshment' was done.

I then changed the track rods and ends, all four discs and put new pads on. No improvement

Then we toed in the rear wheels a tad and the wobble got better! So I took it for a 'proper' 4 wheel alignment.

The car drove superbly after this and the shudder was better but nowhere near where it should be.

I was getting really disheartned, the car has had nearly all suspension parts changed, I've spent over £1200 and its not right - I was angry!!

Thinking it might be wheel balancing I persuaded my father to give me the wheels off his 330ci for a few hours. This was easier said than done because my 16"s wont fit over his front or rear brakes - we had to take the calipers off the rear, why is nothing ever easy?

It drove exactly the same with his wheels as with mine, shudder wobble shudder!

I am taking the car on a 2500 mile trip to Spain in 2 weeks, the thought of having a wobble all that way was really getting to me. My wallet was open and I was looking for things to buy to put it right

Anyway, reading bimmerforums they were all raving about how the 'only' way to have your wheels balanced was on a a Hunter GSP9700 Road Force machine. ( <http://www.gsp9700.com/pub/features/StraightTrak.cfm> )
Many were having 'shimmy' issues despite multiple 'normal' balacing's that went away when done on this machine.

Searching here I found the link of www.alignmycar.co.uk <http://www.alignmycar.co.uk> which has a list of places with this kit. The nearest one being Bentley Cardiff who quite promptly told me to fck off if I thought they would balance the wheels on a BMW there.

The next nearest was Northampton, a full 180 miles from home. Lucky my GF's parents live there and we had an FTO with a broken gearbox to drop off in Brum...

I've just had them done on this machine, cost of £10 a wheel which is only a bit more than normal. What is special about it is that it has a roller which loads the tyre to simulate it actually driving on the road.

Now I'm nervous as hell driving out of the garage, if the wobble isn't gone I'm gonna cry!

I find a nice dual carrigeway and gingerly accelerate to the wobble speed..
60...fine....65....fine....70...fine...75...fine...80....fin e....85...fine!!!!!!!!!wooohooooooo!!!!!!!

Freaking car is smooth as silk now, no wobble or even a hint of one. I am so bloody happy, I really though I'd never get this fixed

The only thing I can think of is that the PF bushes make the car hyper sensitive because my dad's wheels are mint with brand new rubber and a fresh balancing, they don't wobble on his car but they did mine.

My car 'only' has 90,000 miles and to be honest, everything bar the bushes looked in great nick. I've spent quite a bit changing parts I didn't need to, I have peace of mind now though and the car feels very tight.

Thats a big long post but if hopefully if anyone else is/was/will suffering something similar they will find it useful. I never had much confidence in the usual crappy tyre garages and this goes to prove it. Balacing at those places is fine for run of the mill cars but obviously the tolerances are too great for something stiffened up.

Now I'm off to spend the extra money left over I had found to fix this, on something shiny

**************************************************** &n bsp; 

Does this sound similar to your situation?

Cheers

Pegsta wrote: Cheers Mate!!! that sounds exactly like my situation. I'm in half a mind actually to have the poly bushes replaced by standard ones if I'm going to get this sort of malarky all the time. But I think I'll hunt out one of those wheel balancing machines first.  Cheers again. Gaz

Wherabouts are you roughly in the country?  

Pegsta

Are you sure it is a Hunter GSP9700 Road force one? They are like a miniature rolling road not a conventional tyre balancing machine. The reason I ask is because Hunter also make the more normal types of wheel balancer machine but they don't work as well.

If BMTR have got a GSP9700 Road Force model then please let me know - keep us informed how you get on as well

Cheers

Ok - so I didn't get to BMTR.  I went to my mechanic for him to take a look at the car first as he knows it.

We jacked it up and span the wheels (the rears were spun under power). 

What we found was the front offside alloy was ever so slightly out of shape and the rear offside alloy was out of shape.

We've swapped the rear nearside with the front offside.  I've yet to give it a propper run as I had to get home shortly after that but I'm going to put it through its paces properly on Monday and see what happens.  Felt ok though on the way home.

I'm annoyed now though as www.autoalloyz.co.uk had a brand new set of my alloys with tyres for £225 a month or so back...  I could have had those and then sold my current ones for that much to a second hand alloy dealer.. (already had a quote from one for them).

Oh well.....

Cheers

Gaz

Theory goes (and I'm a great fan of theory) that I shouldn't notice too much if any wobble having the dodgy wheels at the back.  They'll certainly do until I am able to get my hands on a decent pair of replacements.

Well it'll be getting it's first proper run tomorrow on the way to work so I'll know more tomorrow evening.

Cheers

Gaz