Friday, 24 December 2010

196,000 Miles

Handling issues are developing, as always. I have been of the impression that all my handling problems have been related to the front end bushes. But a new noise has drawn my attention to the rear end of the car.

I am getting a very audible 'clunk' from the rear end every time torque is applied. i.e. every time I abruptly (although it is now getting easier to invoke it) de-clutch or engage the clutch or even just apply power the back end clunks.

After discussing it with a friend and reading up on it a bit, I seem to have very classic symptoms of worn rear subframe bushes.

Here is an extract from the very useful E34.net site describing my problems exactly:

Rear clunk noise when you disengage the clutch on an upshift / down shift; especially an upshift. when accelerating; the subframe is pulled away from the chassis via the wheel torque. when you push the clutch in, the subframe unloads and hits the chassis creating the thunk.
The rear of the car feeling like it steers itself. Probably best to do the rear pitman arms first before the subframe bushings if you have a self steering rear. or, at least have them inspected. If the pitman arms are good then this means the bushings are soft. No real way to inspect the bushings visually. however, if you support the subframe, you can easily remove the arm covering the bushing and see how torn it is.

The clunk is VERY apparent and also, the feeling of the rear end of the car self-steering! Yes, exactly! This now over the last few weeks seems to have really deteriorated and it clunks badly all the time.

But for ages I have had the sensation of the rear of the car seeming to steer itself. Many times I have rocked the back of the car wondering if something was wrong at the back. Also, when driving straight, say 50mph, if I wiggle the car left and right, rapidly to make it wobble, once I stop wiggling the steering wheel, the back end of the car seems to squirm around by itself for a second or two longer!
Definitely need to change them bushes!

Will make up a simple extraction tool to pull the old bushes out see how much of a difference it makes. I still need to replace the front rear control arms for quality Lemforder parts and am also going to upgrade the bushes to 750i bushes.

No comments:

Post a comment