Excess rear camber at stock ride height

[aaronhoy]

1998 740i non-L non-sport. I bought the car at around 200k miles. It has an alarmingly noticeable (just by looking at the car from behind) amount of rear camber which is starting to wear the tires unevenly. Up until now, I had assumed that the springs were shot and the car was riding too low, causing the alignment problem. However I looked up the specs and measured today and it's actually riding slightly higher than the spec. Then I stuck my head under there to have a look at the eccentric bolts that are used to adjust rear camber, and they are sucked in all the way (minimum possible negative camber).

So what gives? It seems like at stock ride height, the stock alignment adjustment would be capable of putting the angle into spec... I don't see any visibly bent arms or anything like that, and the angle is approximately symmetric left and right (so it seems unlikely that something is bent from an accident). Any ideas?

[Alpine 7even]

There's a rear camber adjuster on the lower control arm bolt. Post up pictures.

[aaronhoy]

Thanks, I'm aware of the bolts you speak of. I stuck my head under there to look at them, and they are sucked in all the way (minimum possible negative camber).

Attached are some pics. It's dark out and my camera sucks at low light so it was hard to get any pics that do issue justice, but just in case here they are.

In the first pic, you can see my rear ride height being measured. BMW specs 569 +/- 10 mm from the bottom of the rim to the fender. I measured about 23.25 inches which comes out to about 590mm (so actually out of spec on the high end, I would expect being out of spec on the low end to cause excess negative camber).

In the second pic, you can see the visible negative camber.

In the third pic, the tread wear, but the pic doesn't do it justice. The inner part of the tire is worn more than it looks in this pic.

In the fourth pic, the eccentric bolt. Again, the pic doesn't really do it justice. The bolt is set to have the bottom part of the suspension pulled all the way inwards towards the diff as far as it will go, so rotating this will only make the camber even more negative. I know in the pic it looks like it's rotated down all the way (so about half way through it's range), but when you see it in real life, it's clear that it's all the way to the left (this is a pic of the right side rear wheel from behind).

[energizer821]

i have the same thing on mine too! it looks just like that and mine at stock height. but mines a sport with sport suspension....

[Alpine 7even]

Looks to me like you are in need of a rear lower ball joint replacement and possibly upper rear control arms.

Ball joints
http://www.oembimmerparts.com/product_p/33326767748MYE38.htm?gclid=CO6eid2Ho7QCFSXZQgod7nQ AWw
control arm
http://www.oembimmerparts.com/product_p/33326770059-060E38.htm?gclid=CISc1ZCIo7QCFSmCQgodNB0ANg
Trailing arm
http://www.oembimmerparts.com/product_p/33326768791e38.htm

[Silver740ILL]

Negative camber improves handling in turns and decreases oversteer in turns. Euro manufacturers have been doing this for years. Tire life is decreased.. But when you have the $$ to purchase these cars new tire life doesn't matter..

[Alpine 7even]

Negative camber improves handling in turns and decreases oversteer in turns. Euro manufacturers have been doing this for years. Tire life is decreased.. But when you have the $$ to purchase these cars new tire life doesn't matter..

Not when neg camber exibits inner wall wear like his is showing. Replace those parts and have an alignment done and you should be good to go.

[aaronhoy]

Negative camber improves handling in turns and decreases oversteer in turns. Euro manufacturers have been doing this for years. Tire life is decreased.. But when you have the $$ to purchase these cars new tire life doesn't matter..

Yeah, I know that negative camber improves handling and all, this is a 7 series after all, and I'm not exactly tracking the thing. I also have an E30 convertible for tooling around and an E36 M3 for the track, so this car is more for long road trips and stuff. Given that, I'd be more interested in improving tire life than squeezing a little extra grip out of the tires.

I'll examine the bushings and ball joints more closely tomorrow when it's light out and I have a chance. Is there any way to get just the ball joints/bushings for the upper control arm and trailing arm? I hate to replace an entire huge chunk of metal just because one small part press-fit into it went bad.

[Alpine 7even]

Unfortunately no. At least not that I've found.

[Silver740ILL]

Not when neg camber exibits inner wall wear like his is showing. Replace those parts and have an alignment done and you should be good to go.

Any negative camber will result in inner edge wear. I'd have someone check the alignment before replacing all those parts. Those tires look low tread wise on the outer edge too. What's the factory spec for rear camber? I'd bet its close to or more than 1.0 degree. Slight rear toe in will compound the inner edge issue.

[Alpine 7even]

Any negative camber will result in inner edge wear. I'd have someone check the alignment before replacing all those parts. Those tires look low tread wise on the outer edge too. What's the factory spec for rear camber? I'd bet its close to or more than 1.0 degree.

Yes I realize that, but look at the wear pattern!! It's way to far inward! I'm mean come on, it's obvious!

[Silver740ILL]

Yes I realize that, but look at the wear pattern!! It's way to far inward! I'm come on, it's obvious!

Yes I see it has inner edge wear. I'm just saying that it may just need an alignment. I disagree that it's as bad as you think.. Sorry.

[Alpine 7even]

Yes I see it has inner edge wear. I'm just saying that it may just need an alignment. I disagree that it's as bad as you think.. Sorry.

An alignment isn't going to do much if the camber bolt is already pulling the wheel in as far as it can go before it starts pushing out again.......lol

But I suppose one must be proven wrong before one can grow. :D

[Silver740ILL]

An alignment isn't going to do much if the camber bolt is already pulling the wheel in as far as it can go before it starts pushing out again.......lol

But I suppose one must be proven wrong before one can grow. :D

You've proven no one wrong.. I'm looking at pics posted on the Internet and suggesting the OP's alignment be checked by a professional.

You on the other hand have diagnosed his rear suspension as needing all these repairs without having seen the car let alone shaking it down...

[Alpine 7even]

You've proven no one wrong.. I'm looking at pics posted on the Internet and suggesting the OP's alignment be checked by a professional.

You on the other hand have diagnosed his rear suspension as needing all these repairs without having seen the car let alone shaking it down...

Well my diagnosis may have something to do with the fact that I have 3 e38s (that have and are being completely Rebuilt), an e30, an e46 and I've had an e36 m3. And i have built a full drift sivia and a track day gen2 mr2. So I've pretty much seen everything. Ehh but what do i know....:D. Also, I never said I had proven anyone wrong, I said "one must be proven wrong". Haha :lol

Anyway this isn't our thread to derail so agree to disagree chief.

[Silver740ILL]

Pissing contest..

I run an automotive repair shop and make a living repairing vehicles myself...

Nice to see you owned a variety of cars and can drift.. Chief.?

[Alpine 7even]

Pissing contest..

I run an automotive repair shop and make a living repairing vehicles myself...

Nice to see you owned a variety of cars and can drift.. Chief.?

Hey I own a BMW specialty performance/repair shop and make my living that way as well. So....What?

EDIT: look I don't really care. I'm just giving advice from my own experience. The op will do what he thinks is best.

[Silver740ILL]

Hey I own a BMW specialty performance/repair shop and make my living that way as well. So....What?

Nice

[Alpine 7even]

Nice

Thanks!

[energizer821]

I have 3 e38s (that have and are being completely Rebuilt), an e30, an e46 and I've had an e36 m3. And i have built a full drift sivia and a track day gen2 mr2.

I'm sooooo jelly. You lucky man

[Alpine 7even]

I'm sooooo jelly. You lucky man

:D

[aaronhoy]

Yesterday while it was still light out I got out there and inspected things. The ball joint part of the control arm (part #17 below) was noticeably loose on both sides. Also the ball joint boot for part #13 was pretty messed up on the one side.

http://www.realoem.com/bmw/diagrams/o/v/2.png

While those ball joints were clearly in need of replacement, I wasn't totally convinced that the amount of negative camber I was seeing could be caused by that amount of play alone, and since I'm going to have to get the car aligned anyway and I hate doing that (lots of bad alignment experiences, see other posts), I just went ahead and got new arms (both 17 and 13), new ball joints and integral links (2 and 4). And some front end bushings. It still really annoys me that you have to replace the entire arms. Once my new parts arrive and I put them on, I think I'll press the old bushings out of the old arms and measure them and see if I can't find a generic bushing-only part number that fits.

Also, I could not find anywhere that the inner, lower bushings could be bought independently (the ones in the left hand side of part #8 that bolts 11 and 9 go through) and not a lot of places seem to even sell the entire replacement #8 part with bushings (not to mention it would be way more expensive). Do those bushings just tend not to go bad as soon as the others?

[Alpine 7even]

Glad to see you we're able to figure out the issue! Part #8 I had the same issue with. So I ordered polyurethane bushing from strong-flex over in London. I would look into that!

[aaronhoy]

Glad to see you we're able to figure out the issue! Part #8 I had the same issue with. So I ordered polyurethane bushing from strong-flex over in London. I would look into that!

Wait, I assume you don't mean that you replaced your ball joints with polyurethane bushings (you just replaced the inner ones that were originally rubber, right)?
Edit: wait, sorry, I see. You are talking about part #8. I didn't check the diagram before replying :p. I was thinking of #13 and #17.

Anyway, I did consider something like that, and I've also read about guys buying the stuff to mix their own polyurethane and similar bushing materials (2 part epoxy style stuff) to make custom ones of an exact shape, which would be good if there didn't happen to be any aftermarket bushings available for this application. I'm a little hesitant to go polyurethane on this car though. I replaced some of my E36 M3's bushings with polyurethane and it did make things noticeably noisier. That was fine for the M3, but this thing is more of a highway luxury cruiser, so I kinda wanna keep the noise to a minimum.

[GSXRliterbikz]

Its pretty rare for those to go bad. I have some extra swing arms (part 8) laying around if you find they need to be replaced.
But likely its just the ball joint and arms that need changing.

[aaronhoy]

Ok, good to know since I didn't get replacements. I guess when my new parts arrive and I get everything taken off I should be able to wiggle that #8 part around more freely and find out for sure what the condition of those is. I have been toying with the idea of getting some junkyard ones that have mount tabs for a rear swaybar (I do not have one right now :( ). And in that case, since I would have the extra set to play with while the other ones are still on the car, I would definitely look into other bushing options.