Need some extra rear camber adjustment?

[oldskewel]

Common issue on these cars, it seems, to not be able to adjust rear camber within spec (-1.5 to -2.2 degrees).

Camber out of spec, and failed suspension components can lead to extremely fast tire wear on the inside shoulders of the rear tires.

On my 2001 E53 3.0i with spring suspension, the rear ball joints (33-32-6-767-748) were the root cause. Another common one, very easy to replace, and sometimes gets it done without needing to dive all the way in to the ball joints, is the rear upper control arms (33-32-6-770-859 and 33-32-6-770-860).

Some have found the swing arm bushings worn out. There are aftermarket replacements allowing replacement of just the bushings vs. the full swing arm.

I replaced my ball joints and rear upper control arms shortly after getting my x5 a few years ago. Aligned within spec (-1.8 and -1.9 on L+R), apparently easily (did not do it myself).

Years and miles later, I found a need (more of a want ) to do a quick alignment since the steering wheel was off by a few degrees. Car drove fine, as it always has (even with the multiple issues when I first got it).

In doing my homebrew alignment, I found the rear right camber was out of spec, at about -3.5 degrees, along with the beginnings of tire wear on the inner corner.

I found the camber adjustment back there to be already about at its limit. Here is a pic of the bolt end of the eccentric adjustment. The bolt end faces forwards, so this pic is looking back.



This shows why I am unable to dial in the camber adjustment I need, even with new, good suspension components. Basically everything that could be affecting camber back there is new already except the swing arm bushings which do not look to have any problems.

The eccentric bolt head there is supposed to fit within the two ~vertical surfaces (stamped steel, reinforced with welds), so when the eccentric turns, the center of the bolt slides left or right, moving that suspension pivot point. In this case, wanting to reduce camber, making the wheel more upright, I want the center of that bolt to move inwards (to the right in the photo). Partly due to that surface being damaged / gone, partly that the nut-side of the setup has issues as well, and I think partly due to the whole suspension being stressed due to the spring, the center of that bolt does not move inward as needed.

The whiteout mark shows the "before" adjustment location. Made that mark and took this pic before I knew of this issue. Expected I'd be able to dial in the required adjustment.

So with this situation, no adjustment was possible and the camber remained at -3.5 degrees. With all new suspension parts already, I did not know what I'd do to solve this, and searching on here came up only with aftermarket adjustable rear upper control arms as documented solutions. I did not want to go that route, hoping to keep things stock.

This is the limiting problem I've got. If anyone is in a similar situation = known good suspension components back there, stock wheels, springs, etc., not lowered, and you're still getting excessive negative camber and tire wear, you might want to take a close look at the actual eccentric adjustments. The nut-side faces rear and is easily visible just looking under your car. If nothing else, before you take it in for an alignment, you can see if the eccentric is already trying and failing to get things more vertical. That would save you the alignment cost and effort.

[oldskewel]

And here is a pic of a similar situation on the left (port, USA driver's) side.

Not near as bad as what the right side shows, and camber is still within spec on the left, but you can see similar deterioration of the eccentric pushing surface and the gap between the left side of the eccentric and its pushing surface. This makes me think it may be a common issue for people with rear camber issues.

[oldskewel]

The following pics are from the right side, after I did my own adjustment.

The bolt seems to have moved about 2 mm on the front (bolt) side and a little more than that on the rear (nut + washer) side. This reduced camber from -3.5* to -1.4* . I could have got more if I wanted, but just did this quickly and found myself right near the spec limit (-1.5*) so called it good.

The pics show the overall view, the remaining gap on the inboard side, and how much motion was achieved (on the outboard side, looking at the whiteout mark to show the "before" location).







And that last pic shows a close up view of exactly how the eccentric pushing surface was previously damaged. PO went through many sets of tires at about $1500 every 20k miles or less.

[oldskewel]

So how did I do the adjustment?

After noticing this issue and thinking (but really not sure) it might be the root cause of the excessive camber problem, I tried levering things with a pry bar. Maybe I could have tried harder at that, but it got nowhere.

So I went full overkill and (I still don't know how much of this is all actually necessary, but it was very easy and did not take a lot of force to move things):

Compressed the suspension spring. If I had airbags, this would be very easy. But I had to use my little old spring compressors. I jacked the suspension to fully compress the spring, fit the compressors in there (barely fit, and these are very small compressors), and jacked down the suspension, moving most of the supporting force back to the jack stand. So the spring was still in place, but was no longer stressing the whole suspension. This made things much easier to move.

^^^ But I'm not sure how much that step is necessary. It was convenient for me, and I thought it would help so I did it. If you have air bags, deflate them. If you have spring, but no compressors, I'd skip that step - you might need to pull harder on the winch, but I expect things would still move.

Removed the eccentric nut and washer, so I could see how the bolt moved. "After" photo in a following post.

Used a winch / come-along between the left and right shock supports, with C-clamps as interfaces to pull the left and right suspension towards eachother.

With things freed up due to the spring pressure being removed, it moved very easily, with hardly any force needed. I moved it so the rear/nut side of the bolt could be seen up against the end of travel limit (shown in photo in following post), then tightened things. I expect it moved a little while I did this, so that bolt is no longer at the limit shown by the photo.

Removed spring compressors, etc. Torqued that rear nut to 165 Nm, and measured camber at -1.4 degrees .

[80stech]

Haha, "free alignments" for the PO from the tire shop no doubt.

[oldskewel]

Pics of the homebrew adjustment:



Spring compressors in place, suspension jacked but backed off, so it is relatively de-stressed.

-------------



Overall view of the winch / come-along used to gently pull the left and right sides together. Very little force was actually needed here to get things to move. This just allowed me to get it moved securely and easily, working alone, taking it slow and careful.

-------------



Close up of right side attachment. The C-clamp is not tightened. It is just a convenient interface to get the hook on the winch to pull on the lower shock mount.

-------------



Same thing on left side.

-------------



Right side camber adjustment bolt, rear view, where the eccentric washer and 21 mm nut go. When first removing the nut, even at full eccentric-driven adjustment, the bolt was in the middle of the left-right adjustment slot seen there. No pic of that.

This pic is after pulling left and right together, bolt here is as far inward as it can go. I think the bolt-head end of this bolt may have had a little more to go, and when installing the washer + nut, and torquing, I expect the bolt moved a little off the limit there. If needed (i.e., desperate), I probably could have shimmed in that gap, preventing the bolt from moving outward at all when finishing things up.

As it was, I lucked out, and ended up at -1.4*, which is almost exactly what I'd get if I could pick anything I wanted, so of course I called it done and have not touched that nut and bolt since.

[EODguy]

Awesome write up!!
I would have been all "Hulk smash" or tried to make a different oversized offset washer.

Sent from my SM-A730F using Tapatalk

[Fifty150hs]

I had a similar problem on my 2006. Only on one of the swing arms. Some dipshit at an alignment shop backed the eccentric off too far, allowed it to ride over the stamped protrusion and then tightened it which flattened the protrusion. I took it apart and got in there with a air hammer and pushed the protrusions back out so the eccentric would engage properly.

[timmyc]

Great insight, Oldskewel!

So the washer should bind in between the shoulders? Kind of a janky setup. Seems like Fifty150hs' problem could be commonplace. Especially in shops who don't deal with bimmers often.

I'll be checking on mine ASAP!

[oldskewel]

Yes, I think this may be a fairly common issue. It probably just takes one badly done alignment adjustment to screw things up - as @Fifty150hs found as well.

And calling them "shoulders" makes so much sense. I did not know what to call them, but that is clear. I don't know how much gap is supposed to be on either side of those eccentrics, since my shoulders are all messed up .

I think due to the spring having things under so much stress, it should be a pretty easy mistake to make - undo the nut a little too much, so the eccentric bolt head and eccentric washer can rise over the shoulders, try to rotate the bolt to do an adjustment, but the spring tension makes this difficult and the head and/or washer can easily slide over the shoulders or mash them away as it seems happened on my car in a few places. For people in most parts of the country, throw in some rust to weaken things and obscure visibility, and of course it is even more likely to be a problem.

I realized as I was writing all that up and posting the photos that I can actually see a lot more in those photos than I ever knew while figuring things out and doing the fix. So for others, this suggests that a quick visual inspection may or may not fully reveal the problems. Taking your own well-lit close-up photos and inspecting them may be needed.

Seems like so many times (like I was back when first getting this car, and right before I solved this problem here) people have cars that drive just fine, but have un-correctable excessive camber, tire wear, and need to do a ton of work just to get an extra degree or so. I'll guess (did not analyze the geometry, this is just based on how much I moved that bolt and how much camber changed) that you get almost one full degree per millimeter of adjustment there.

If they're wanting to try a fix without doing all that work, this might help. And even if they do all the work and still have a problem, this may be it.

I'll also give a strong endorsement here for doing a DIY string alignment. I did a total of 3x of those throughout this repair process, including a couple of weeks and 50+ miles between the first and last ones. Of course the rear measurements changed and needed adjustment due to this camber adjustment (*). But the front toe alignment needed no adjustment after the first time - confirming repeatability of the measurement procedure. I estimate I got 0.5 mm accuracy or better on the toe measurements, which is about 0.04 degrees or better. Spec is 0.08 to 0.22 degrees of toe in.

The best thing about doing my own alignment was that it actually allowed me to solve this problem. I don't think it would have been possible if I were taking it in for a professional alignment and then trying to figure out what they did as an extra random variable. This episode here was the first time I had touched the rear alignment myself - had previously all been done professionally, and was of course kind of a mystery to me.

(*) - and I also finally put in new Lemfoerder guide links (33-32-6-774-796 ; Lemfoerder 27082 02) when I noticed their boots were cracked while I was adjusting rear toe, and "since I was in there" - but after removing and inspecting more carefully, I can see these original parts with almost 200k miles on them are actually still greased, tight and centered. If it was worth doing, they just needed new boots. Very impressed with the original parts here.