Hmm, help?

[Ferret]

Right,

I've just finished changing all the suspension arms over on my E31, as the car was drifting around very badly whenever the brakes were hit, and was totally unpredictable.

I've tightened up the steering box, as there was quite a dead zone in the centre.

However, the right hand side shock tower was covered in oil, I'd put it down to the fact that the engine currently has a major oil leak, but I'm not so sure now.

On the way down to work, at the end of a high speed stretch there's traffic calming measures - read, frequent mild bumps in the road surface. When I hit the brakes hard, slowing down on this section I get absoloutely massive shuddering thumps through the car and the car starts to shift sideways on the road...

Would a shock out cause this, or should I be looking elsewhere? The bits I've not replaced are:

The centre tie rod arm
Shock Absorbers
Drop links

[Black 535i]

Have you done any work on the control arm bushings or ball joints? They would cause the car to rock back and forth under braking for sure. I just rebuilt my whole front end last week and have no issues with any squeaks or looseness at all now. Also check the strut mounts at the front for cracks.

[Ferret]

Have you done any work on the control arm bushings or ball joints? They would cause the car to rock back and forth under braking for sure. I just rebuilt my whole front end last week and have no issues with any squeaks or looseness at all now. Also check the strut mounts at the front for cracks.

The control arms + bushings are brand new
Thrust arms are new with powerflex bushings
Steering tierods are new on both sides

All aligned up by laser tracking

This isnt just like a minor shimmy, this is major bucking/shaking/slamming motion as the car's coming to a stop. Seriously think that one of the shocks may have gone, it's an excuse to throw bilsteins at it anyway I guess...

[Bo525i]

Sounds like a blown shock or a broken spring to me..

[Interceptor]

This isnt just like a minor shimmy, this is major bucking/shaking/slamming motion as the car's coming to a stop. Seriously think that one of the shocks may have gone, it's an excuse to throw bilsteins at it anyway I guess...

I'd bet the front right shock is blown.

[Ferret]

I'd bet the front right shock is blown.

Hmm, I'm pretty sure it is now, I've just been out at lunchtime tinkering, bouncing the front left corner of the car produces a noticable hiss from the front left shock.

Bouncing the front right of the car produces no sounds from the front right shock, and a noticeable hiss from the shock on the other side...

[Black 535i]

All that torquing on the struts could not have helped them. Not much work or cost while getting the shocks out anyways. Good luck.

[Ferret]

All that torquing on the struts could not have helped them. Not much work or cost while getting the shocks out anyways. Good luck.

Yeah, will do.

Just having trouble sourcing the bilstein parts now, for the record front E31 shocks are bilstein part PE3-B009

I hope they come with a new locking collar - bmw will not supply this as a separate part, they'll only supply the complete assembled strut.

[genphreak]

It'd make sense if it had front and rear SLS (not sure of any e31s had this, but M5 and 540i Sport did) should one of the front shocks be leaking, though gas shocks can leak and do this too. Maybe you can get the Sashs shocks if it has the normal gas ones?

[mzarifkar]

you have ruled out brakes? all connections are tight?

[Ferret]

Turned out that the front right shock was totally failed, there was literally -no- resistance to movement on it.

I'll show you a photo of the E31 "strut inserts" shortly - it explains why you just cannot get suspension parts for the front of the E31...