First post - first problem - lean

[Ben]

Hello

csl seems to have developed a lean at the back end. Dunno if it's a new thing or I just havnt noticed before but the left rear side is sitting a good 40mm higher than the right side. I'm calling service on Monday with warranty but just thought I'd check with you chaps to see if it's a known thing.

Thanks

b.

[outnumbered]

Broken rear springs are not unknown...

[glendog74]

Broken rear spring most probably... :banghead: Cheap fix :thumbs:

[mattCSLnut]

Hello

csl seems to have developed a lean at the back end. Dunno if it's a new thing or I just havnt noticed before but the left rear side is sitting a good 40mm higher than the right side. I'm calling service on Monday with warranty but just thought I'd check with you chaps to see if it's a known thing.

Thanks

b.
Very common with many E46s, not just the CSL. While BMW investigate :whistle: the rear springs being broken :hahaha: ask them to check the RTAB (Rear Trailing Arm Bushes), also very common to be worn out prematurely.

[DazBlackCSL]

I have two spoons that might help!!:hahaha:

[Mark CSL]

If it is down at the rear like the boys said sounds like a spring but i have seen a broken spring and the car sits fine :thumbs:

[Bounce]

I had a broken spring,and you would never have known.

[shimmy]

All this talk of broken springs, Matt will be wondering where he can buy one next.

[AlexGTT]

All this talk of broken springs, Matt will be wondering where he can buy one next.

Group buy anyone? I'm sure we can squeeze the last drop of blood from some poor sod trying to run a business.........:whistle:

[glendog74]

Group buy anyone? I'm sure we can squeeze the last drop of blood from some poor sod trying to run a business.........:whistle:

Now, now, Alex! :gayfight:

[Thorney]

If its something that has developed over time then I'd agree its likely to be a spring (which actually isn't that common on CSL's but rampant on M3's). However it may well have always been like that and now you're just noticing it more, the bodywork on the car is notoriously innacccurate, when we set the cars up we do it on the chassis rail and the shock body to make sure its the car thats level, if the bodywork is out then c'est la vie, its the car you want set up right not the body.

[Ben]

well here's an update with a confusing outcome :

not long after this thread was started (after you kind replies - thanks chaps) I dropped the car off at BMW to investigate the lean, my original estimate of a 40mm difference side to side was, with hindsight, a gross exaggeration, but still the car was leaning, after a crude measurement, 15 - 20mm. Anyway, after a day down at service they called to say the car was perfectly fine and they had calculated that the difference was 5 - 7mm which is within their tolerance of ±10mm. I was skeptical following my previous observations so on my arrival we took it outside, so to speak, to a very flat car park and applied the tape measure. Sure enough I struggled to reproduce measurement exceeding 10mm. Felt a bit of a wally but it wasn't a complete wasted trip as they fixed my dicky handbrake. So I drove it home and put it to bed in the garage.

So this was all over a month ago, being a nice day today I decided to give it a run out, in the car park of our destination I noticed lean again and on measurement back home in the garage this afternoon, I observed a 15mm difference side side with the tape, from floor to top of arch 670mm passenger side, 655mm drivers side. So I dug out the jack and did some investigating. Got it up in the air, and saw no signs of a broken spring, spring pads matched and nothing else unusual. Dropped it back down again.........hey presto, 670mm bang on both sides.

So this must be down to a problem with some dynamic suspension component?? maybe damper wear over time?? inconsistent rebound?
I'll keep an eye on it and see if it settles at its previous level. As a quick fix I'm tempted just to bung in a thicker spring pad, am I right in thinking standard pads on the CSL are 5mm at top and bottom?

Its become a bit of a mini project now, and I'm curious more than anything to find the cause, so any ideas would be welcome.

Ta

b.

[karbonkid]

I would take to a specialist if concerned and forget BMW as I find them mickey mouse and only good for replacing parts under warranty (if you have warranty). Im guessing you have OEM suspension, as with coilovers the height may differ slightly due to the varying spring preloads required to acheive the optimal corner weight setting, unfortunately there often has to be a bit of a compromise on looks to acheive the perfect balance in handling. Not sure what the lean may be about. Where are you located?

[daniel]

which side? your fuel tank is on the drivers side as is steering etc so this will increase the droop on that side. store it low on fuel and see what happens.

[DuncanR]

Ben,
put your wallet on the passenger seat mate, instead of in your hip pocket !:thumbs:

[NZ_M3]

Every single CSL I've measured have had the left rear quarter sitting high - it's normal.

The factory allows a 10mm tolerance between left and right side.

Remember these cars were engineered to be left hand driven, so it is normal for the left hand side to be sitting a couple of mm higher.

What you might be seeing is the swaybar binding and holding one side up more compared to the other. What I would do is check the U bushings on the sway bar mount to make sure one isn't worn out compared to the other and put some graphite grease in it to allow the bar to move.

Also measuring from the ground to the top of the arch isn't the correct way of measuring - tyre pressure difference could also cause it to be out completely. The correct way to measure (and it is how BMW measures) is from the bottom of the rim to the top of the wheel arch)

Stock spec is 610mm +/-10mm for the front and 600mm +/-10mm for the rear.

I've yet to measure a CSL that doesn't have a rear left sitting between 7 to 10mm taller compared to the right rear - NEVER (more if you have a light weight aftermarket muffler - the muffler alone can contribute to about 3mm difference)