Front end replaced..STILL got shimmy/vibration grrrrrr

[Philip1972]

Well today I had the front upper and lower control arms replaced, as well as tie rod ends and drop links.

Still getting the shimmy through the car, so it MUST be the from the rear, surely?

Does anyone have any help/suggestions or ideas? It driving me a bit potty to be honest!

Thanks

 

[Stratman]

If yours is a W208, you have a steering box and damper. The damper is a known weak point but is also easy to replace.

Can you feel it through the steering wheel? Does it change with road speed? The more information you give, the better the chance of a diagnosis.

 

[Philip1972]

Sorry, its a W209, 2003.

Nothing through the steering wheel, just feel it through the seat. Happens at 60+ and does go away at 100. Ideally I would always drive at 100+, but that's not always possible

Its a bit odd, as sometimes its worse than others-I sometimes thinks its worse after 6 or 7 miles, after its all warmed up, but I cant really be 100% sure about that.

I have had a new set of Mercedes genuine wheels that balanced perfectly to "0", and were 100% straight (this was done by a garage that has a very good reputation for wheel balancing problem cars).

I thought it was the control arms because when hot and at 70, braking caused a slight wobble through the wheel but not at other speeds. When it was on the ramp though I hand spun the wheels and they spun very freely with no sticking points. I also assumed that if was the brakes, that in order to cause the shimmy they would be warped enough to feel all the time when braking.

Thanks again

Phil

 

[brucemillar]

Check prop shaft rear flex disc is in good condition.

Sent from my iPhone using MBClub UK

 

[Stratman]

Like brucemillar says, check the propshaft. The engine mounts can also cause a few strange vibration problems.

 

[John Jones Jr]

It's worth a shot rotating the wheels front to rear.

 

[Philip1972]

Thanks for all the help so far.

 

[V8 Supercharger]

My cars been doing this for over a year now and iv almost replaced just bout every bush there is on it . . . . . still doing it. Although i get it between 25-40 mph and then again between 60-80mph. Its definitely from the rear.

The thing i recommend you do rather than getting mechanics to take it on road tests is to test it on a ramp instead. With mine, i put it over a pit, had the rear wheels lifted off and then got it upto 35mph. The whole back end of the car was shaking like a crackhead, and this is without the weight of the car on it.

Eventually i did the same test without the rear wheels on the car, and it pretty much stopped the vibrations. Strange thing is that iv tried 4 different sets of wheels and tyres on it since and on the road it still vibrates to a various degree on all of them. I cant believe 4 different sets of wheels and tyres would all have the same problem, especially when they dont do it on the cars they originally came from.

So far iv spent nearly £3000 on engine mounts, tranny mount, propshaft rear flexi disc, front ball joints, front wishbones, new wheels and new tyres.

My next step is to replace the rear subframe bushes, which is around £800-900 on my car, and if it still does it then im gona cry like a little girl.

But i would suggest you start by getting your car onto a ramp and see if you can figure it from there, it will save you a lot of time and hassle. Do 2 test runs, one with your rear wheels on and one without, see what difference it makes.

 

[V8 Supercharger]

I have had a new set of Mercedes genuine wheels that balanced perfectly to "0", and were 100% straight (this was done by a garage that has a very good reputation for wheel balancing problem cars).

Who did you get this done from, not Wheels In Motion was it?

 

[Philip1972]

Who did you get this done from, not Wheels In Motion was it?

No, it was ABP Motorsport.

Thanks for the replies, its all food for thought.

Did you get the differential mounts changed? Thats my next step, nex Thursday.

 

[V8 Supercharger]

Did you get the differential mounts changed? Thats my next step, nex Thursday.

No i havnt yet, im thinking its something that doesnt like having the weight of wheels on the car, like a hub or a driveshaft maybe. As i said theres no vibrations without the wheels.

My next step is to have the rear subframe removed and just have all the bushes replaced while its out, but that might be a while yet.

Let us know how you get on with the diff mounts?

 

[Troon]

I have a similar problem, documented in other threads. My latest lead is front shock absorbers, which should be arriving in the post today. I'm then getting a trusted local garage to fit them (with the instructions about positioning the clip) and we'll see.

I've read lots of threads where people suggest driveline or suspension items other than the dampers, all of which get replaced with no improvement. If the problem is not related to the power input (i.e. happens on full chat or when coasting), you may have the same thing as me (although maybe at the rear).

Will report back on my results...

 

[Philip1972]

I have a similar problem, documented in other threads. My latest lead is front shock absorbers, which should be arriving in the post today. I'm then getting a trusted local garage to fit them (with the instructions about positioning the clip) and we'll see.

I've read lots of threads where people suggest driveline or suspension items other than the dampers, all of which get replaced with no improvement. If the problem is not related to the power input (i.e. happens on full chat or when coasting), you may have the same thing as me (although maybe at the rear).

Will report back on my results...

It will be interesting to see the results.

I have no wobble or anything through the wheel at all, its all through the seat/floor, hence the rear focus.

Since I had all the front replaced the drive is great, very tought and tight.

Shame about the shimmy!

 

[Philip1972]

I have a similar problem, documented in other threads. My latest lead is front shock absorbers, which should be arriving in the post today. I'm then getting a trusted local garage to fit them (with the instructions about positioning the clip) and we'll see.

I've read lots of threads where people suggest driveline or suspension items other than the dampers, all of which get replaced with no improvement. If the problem is not related to the power input (i.e. happens on full chat or when coasting), you may have the same thing as me (although maybe at the rear).

Will report back on my results...

How did you get on with the new shockabsorbers?

 

[Troon]

No change, although the ride is improved as would be expected. Latest lead is diff angle: see here.