The Project Pad

So I just had my B490Q at Lee's to get some front end work done and the new summer tires on it.

The alignment came out like this:



As you can see, the caster on the passenger side is off, and I'm assuming that's why my steering wheel is about 15% off...

I've talked this over with Lee, and we're thinking a bent component in the suspension. About 2 and half years ago, I put the car into a granite curb while out messing around in the snow (whoops..)

It mangled the control arm for sure but I replaced that and went about driving the car for a while. Now it seems like the issue was never really solved.

My questions is: What is likely to be bent, and how do I measure it? Lee mentioned that in the Bentley there should be a section for chassis measurements but I can't seem to find it...

Candidates:
Spindle
Subframe(?)
strut housing

strut insert and upper bushing has been replaced since the accident.

Thoughts?

For the record, Lee has been very helpful in advising what to look at and even offering a free alignment if I get something figured out...

Couldn't worn control arm bushings do that?

Also possibly having the wrong ball joint installed? If I understand correctly between the late B3 sedan, CQ, and B4 there are two different (front 3-bolt) ball joints that look very similar, but having the wrong one would throw the caster off.

when that control arm was replaced, i put in new bushings...

Ball joint is possible I suppose. I purchased and Lee installed, but I bought for both the left and right at the same time. PNs purchased:

MOOG K90503
MOOG K90504

Depending on how hard your shunt was it's possible your front SF was tweaked.

Shitty thing is it'd probably take a frame shop to determine if it's in spec or not.

it was a pretty good hit... mangled the face of the wheel and shoved the whole assembly back into the wheel liner. Not a proud moment...

The SF is what I'm worried about. Sounds like I may need to start browsing for some parts. I could probably swap out the spindle and strut housing pretty easily but the subframe will take more work...

Maybe I can do a visual inspection soon and go from there.

Well that would stink, but dealing with a bent subframe is a heck of a lot easier than dealing with a bent frame - in the sense that you can just unbolt the subframe and install a new one.

Given the subframe's design, it seems likely if it's bent that the rear part was pushed inward. Kind of like taking a giant circlip and squeezing it a little smaller.

Maybe you can find someone with an extra subframe to measure between two specific points on it, and compare with measurements taken on yours?

If you had gotten the wrong ball joints, you would know it in a hurry. The wheel would be WAY out of center in the arch.

After a hit like that, I would be looking at the subframe. It wouldn't take much of a bend in it to throw the alignment out like that.

One other thing to think about is the subframe bushings. I know mine are getting bad, and my alignment sheet looked very similar.

For reference, here is what mine looks like.

wow, very similar alignment issue there... interesting.

I wouldn't be surprised if it was the SF bushings, I've never touched them and I really doubt the previous owners did...

I do have my CQ SF sitting on the floor of my garage... that should be the same part right?

I noticed they looked very similar too. My caster is off in the other direction though haha.

As for the CQ and B4 subframes being the same, I have to say no. I know the trans mounts on the B3 are different heights, where the B4 they are level. I might have that backwards though.

That alignment was also done with the undersized 034 street demnsity upper strut mounts, so that added to the problem. What mounts did you put in yours?

the b3 90 ball joints are different than the CQ B4 90 ones...did you check to see if you have the same brand and a part number off by one digit for the right side?

895 407 366A vs 893 407 366E

It seems to me that if the ball joints were wrong, both sides would be wrong, no? I definitely ordered a left and a right, two different Moog PNs...

Both upper strut mounts are 034 street density from before I knew of the quality issues... I forget when I bought them but maybe summer of '13?

That would have been during the time the mounts were bad. I got mine around then too. Try throwing a new part of mounts on, and see if that helps.

gotcha, anyone know if they've fixed the issue? Was planning on running Sachs in the rally car... safe bet instead of 034?

They supposedly fixed the issue. I know I won't be taking that chance again. The tires for my 16s are too damn expensive to shred.

Sachs and Boge are the strut top mounts recommended by Mance.

Dave, I've come to realize that sometimes it seems that aftermarket manufacturers sometimes share the same database, which means they get things wrong....ie, B3 90Q = B490Q

In fact it was Lee who figured out that my Sister In law's coupe had a B3 ball joint instead of a CQ... he checked the offset from one ball joint to the other

PRY4SNO wrote:Sachs and Boge are the strut top mounts recommended by Mance.

Sachs bought Boge

Easy way to visually tell if you have the suspect 034 mounts, is that from the side, the rubber isn't conically tapered to fit into the top of the strut tower as the OEM ones