Calibrating self leveling question
 

Hey all, I have been searching the forums and can't quite find the answer to my question. Here is the deal. I have an 03 4.6is. In the winter I run an all weather 18" stock BMW wheel (255 X 55) and run the 20" on staggered summer tires (Vredesteins 315 x 35 rears). I noticed some unusual wear on the inside right rear when I put the summer tires back on (I can't believe I missed it when I took them off early winter). I checked the tires I had run all winter and there was no unusual wear on these.

I took the 4.6 in to check alignment. What it showed is that the right rear was out of the recommended specs. Specs show camber ideally should be in the middle of -1.5 and -2.4. Mine was at -2.6 and could not be adjusted any better than -2.5. That is why it is wearing the inside edge of the tire cuz it was out of spec ie too much negative camber.

After talking with a BMW Indy shop and the alignment shop, both recommed having the rear suspension calibrated to bring the right corner up just a little bit. Is this the approach I should follow? My 4.6 has 93K miles on her. Any advice or suggestions appreciated. Thanks

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"QUOTE- I took the 4.6 in to check alignment. What it showed is that the right rear was out of the recommended specs. Specs show camber ideally should be in the middle of -1.5 and -2.4. Mine was at -2.6 and could not be adjusted any better than -2.5. That is why it is wearing the inside edge of the tire cuz it was out of spec ie too much negative camber. QUOTE"


Woops, I just read the alignment test. Camber specs call for -2.2 to -1.5 degrees ideally in the middle of this range. When I took mine in for alignment the before reading was -2.3 and he could only adjust to -2.2 degrees.

What is the ride height on each side? Measure from the ground to the wheel well at the center of the hub.

check the ride height before and after starting the engine.

Nah, most people can't diagnose this correctly. I bet you have worn rear bushings or balljoints. Search youtube. There was a vid of a guy showing how to diagnose this. The suspension basically has to be under tension to see this.

Have them check again, but show them that vid.

I also think that the OP has worn components at the rear suspension.
I had the same wear, and the outcome was that one ball joint and one suspension arm were worn (had play at the joint)
After replacement, the camber was better (from -2.7 to -2.2), but -2.2 was the minimum we could dial at the maximum of the adjustement.

About the VAC Motorsports video, did someone had success testing using their method?
I tried without success. I made a jig to adapt to my floor jack, and tried many times, with more or less leverage on the knuckle, I then tried to place my jig under the spring nipple, tried on both wheels etc.

I was never able to feel any loose at the wheel.
I then released the air from the rear springs, and only then I could feel some play in the susp. arms and bal joints.

So, anyone had success with the VAC method?

I just had that issue my right rear would not go within spec mine was -2.6 thats the limit the alignment guy could get it to and it would not adjusted anymore also so i change both rear control arm and rear ball joint and after everything was perfect spot on.

Thanks all for the responses. I went out in the garage and measured all four wheels from ground to the center bottom of wheel well before start (bs) and after start (as). I had a 3/4 tank of gas and no one in the car. Here are the results
RR bs 31.7/8" RR as 31.7/8" > no change
LR bs 31.9/16" LR as 31.9/16" > no change
RF bs 31.1/2" RF as 31.1/2" > no change
LF bs 31.1/2" LF as 31.1/2" > no change

I am not sure what this tells me but I would say the RR is quite different than the rest of them ie almost 3/8". I will check out the youtube mentioned in this thread. I suspect that both the alignment guy and the Indy shop would have suggested ball joints and bushings so my question still stands.

Has any one ever gone thru calibration of the self leveling? I know that it can be done but wouldn't the shop check ball joints and other suspension stuff before doing this calibration?

Thanks for all the input, I am gonna research as much as I can to try and get it right. From my untrained eye, there does not appear to be a lot of unusual wear on any of the suspension parts. I do a visual check each and every time I change wheels (twice a year) and look for cracks in the CV boots, worn bushings, leaks, worn brake pads, etc. Any thoughts are greatly appreciated. I still want to pursue the idea of calibrating the self leveling because it would be a lot less expensive fix. Thanks again in advance.

Those are not big differences at all. 5/16 diff from left to right without you being in the car. I would not concern myself with it. And yes, you need to have shops check it properly. Most really don't know how to do this. It is a BMW thing only as far as I have seen. You cannot visually check balljoints. And wiggling the wheel in the air does not work either. You need to check again following those instructions from the video.