help: car pulls to the left or right on uneven surfaces

[digger]

The car pulls quite badly on the wheel both to the left and the right on slightly uneven or bumpy surfaces and is worst under hard braking. The wheel alignment is good been done many times and on smooth roads it tracks true

I have Bilstein HD and eibach prokit (yeah I know) with 25mm IE front adjustable bar and 16mm rear adjustable.

The rack (Z3), steering joints, tierods are all new these helped a bit but problem is still there.

I tend to think that maybe too much rollbar in relation to spring stiffness is not helping but I doubt it’s the root cause.

Which bushes would likely be the culprit? the oldest ones are the top strut mounts of unknown age. others were changed out 60k ago.

[E30_fiend]

If the upper strut bearing has a tight spot it may be the culprit. But i would think your issue is more related to caster. If you have too much caster it will cause a slight shake in the wheel and a very twitchy steering wheel. The hard braking scenario tells me caster as well. When you brake hard, the suspension is under load and sees more caster. If your front control arm bushings are bad, replace them ASAP.


Taylor

[digger]

you mean too much caster from worn CA bushings? there is a slight shake in the wheel but i suspect partly due to rotor warpage

[AndrewBird]

"Darting" like you are describing is generally cause by not enough toe or negative toe. What are your alignment specs?

[jlevie]

When the car was aligned were the rear wheels checked. There's no adjustment there, but worn bushings or damage to the trailing arms can result in misalignment and problems like this.

[E30_fiend]

you mean too much caster from worn CA bushings? there is a slight shake in the wheel but i suspect partly due to rotor warpage

Yes I mean worn CA bushings. Also, the shake you're feeling, is it constant? Or only at certain speeds or only under certain conditions?


Taylor

[digger]

Yes I mean worn CA bushings. Also, the shake you're feeling, is it constant? Or only at certain speeds or only under certain conditions?


Taylor

shake is only under moderate to hard braking.

[digger]

When the car was aligned were the rear wheels checked. There's no adjustment there, but worn bushings or damage to the trailing arms can result in misalignment and problems like this.

i dont know TBH, the rear bushings are a few year newer than the front.

I have pretty much all the bushes F and R on order and will be swapping them in the next couple months. i have the annual rego inspection in a couple weeks so will get things inspected.