Do I need new strut bearings? Video inside!

[Andrew]

I'm trying to diagnose why my car has poor return to center after rebuilding the front suspension, and the strut bearings are my current suspect.  I have reassembled the strut in the order depicted by my schematic.  The only mistake I made was the orientation of the dust seal washer.  The dust seal washer is now oriented as depicted below.

 

Now on to the lovely video.  I dont understand what is causing the rubber to deflect.  I also don't know if this deflection is due to the car being partially disassembled and loaded in a non-normal fashion.  Maybe if the car was resting under its own weight on the ground on its wheels at normal ride height, this wouldn't happen. I also don't know if this deflection is severe enough to cause my return to center issues.  https://www.youtube.com/watch?v=fWj2-0SLSNQ

[B C]

Nice schematic!

 

Did you loosen the strut nut? 

[jc43089]

There will be some deflection because the bottom of the strut is not directly centered over the ball joint.  This will cause the bottom of the strut to move in an arc which changes the angle relative to the top mount.

 

Are you sure it is not attributed to alignment?  You used offset FCABs right?  Is the change in caster causing the difference in feel?

[Andrew]

Nice schematic!

 

Did you loosen the strut nut? 

Thanks:) I have loosened the strut nut.  It does not seem to impact the deflection I am seeing.  

 

There will be some deflection because the bottom of the strut is not directly centered over the ball joint.  This will cause the bottom of the strut to move in an arc which changes the angle relative to the top mount.

 

Are you sure it is not attributed to alignment?  You used offset FCABs right?  Is the change in caster causing the difference in feel?

I was not originally thinking that it should be at the top mount, I thought it should be pure rotation at the bearing, but I agree that if there are two dissimilar axis of rotation, it has to arc.  I guess my next question is, is my deflection at my bearing due to this arc normal?

My return to center could absolutely be attributed, possibly entirely, to alignment, since i have not had an alignment done (you'd think i'd have that done immediately, but i didn't)  Yes i have offset FCABS, but I thought an increase in caster created a stronger self aligning force, which would tend to increase return to center.  I've read that excessive toe out can cause poor return to center, maybe my FCABS introduced a lot of toe out? As soon as I get it back together i'm getting an alignment.                                                                                                                                                                                                                                                     

[jc43089]

The FCAB holes are to the outside right?  You can check your toe in with a tape measure when the car is on the ground, this is really the only adjustment in the front.  I usually go about an 1/8th - 3/16ths inch toe in at the outside of the tire.

[andyhundley]

I went at looked at a e30 once that had offset CAB's and the guy installed them backwards giving the car tons of positive camber. It gave me a serious chuckle!

[Andrew]

The FCAB holes are to the outside right?  You can check your toe in with a tape measure when the car is on the ground, this is really the only adjustment in the front.  I usually go about an 1/8th - 3/16ths inch toe in at the outside of the tire.

 

So i was impatient and bought new strut mounts, and I was going to throw them in this morning, but they are taller (by 6 mm) than what came out of the car!!!  Did the old ones get shorter with age or are the new ones  the wrong part?

[jc43089]

Old ones probably are deformed.  Old engine mounts do the same thing.  The engine mounts I replaced on my e30 were crushed about a 1/4"

[Andrew]

I think I have driven it enough now to conclude that an alignment was all that I needed.  I am an idiot for not getting it aligned immediately after finishing my front end rebuild.

[jc43089]

Eh, live and learn, The front is easy to align yourself, nothing to adjust besides toe in.  Glad you got it figured out.