My car is uneven!

[Twixboy]

The rear end on my 2004 had a side to side height variance that I assumed was due to a broken rear spring. After I got new springs/shocks installed and let them settle for 3 weeks, I still have the side to side height variance. I measured from my flat garage floor to the 4 corner jack points and I'm getting 4.25" at both sides of the front, 4.25" at the rear driver's side, and 4-7/8" at the rear passenger's side, for a side to side variance of 5/8" in the rear.

Is there any reason for concern or is 5/8" still within spec?
Is that 5/8" height variance enough to affect handling on an autocross course?
Why would 1 corner sit higher than the other 3 corners? I'm hoping it's not due to a bent frame.

[Incompatible]

There is generally a small variation in corner heights on most cars. If you looked at your springs carefully before install, you probably would have seen a small difference in heights. Assuming that everything was installed correctly, there are two easy options that should improve the rear difference. There are other factors to consider, but to keep it simple....

Make note of the high and low sides and compare to the rear spring heights when removed - swap springs side to side if needed. BMW makes spring pads of 3 different thicknesses IIRC. Measure yours and change pads as needed.

[The HACK]

They're all like that. Every single BMW I've owned since, like ever, has one side of the rear (typically the driver's side) higher than the other.

My E30 318is, Z3 1.9L, 2x E46 323Ci, Z4 3.0i, E60 545i, E92 328i, E90 335D, and MZ4 Coupe all have slight variances where the driver's side is higher anywhere between 1/4" to 1/2", with the MZ4 Coupe being the least for some reason.

[Vanne]

Hack, is that cos compensated when driver is installed, the car should then be level-ish?

[Twixboy]

Originally Posted by Vanne

Hack, is that cos compensated when driver is installed, the car should then be level-ish?

But it's my passenger side that's higher

Something always looked "off", but I didn't realize it was that much higher until I actually measured it.

[Twixboy]

Originally Posted by The HACK

They're all like that. Every single BMW I've owned since, like ever, has one side of the rear (typically the driver's side) higher than the other.

My E30 318is, Z3 1.9L, 2x E46 323Ci, Z4 3.0i, E60 545i, E92 328i, E90 335D, and MZ4 Coupe all have slight variances where the driver's side is higher anywhere between 1/4" to 1/2", with the MZ4 Coupe being the least for some reason.

If I replace the existing rear driver's side 5mm spring pad with a 15mm spring pad that will even out the rears. How would this affect handling, if one side has a 15mm spring pad and the other side has a 5mm spring pad? What I'm wondering is what's more important - the ride height from side to side or that the springs compress evenly. Should I just leave it alone?

[Westersund]

Originally Posted by Twixboy

But it's my passenger side that's higher

Something always looked "off", but I didn't realize it was that much higher until I actually measured it.

Time to get on a diet!

[UntzUntzUntz]

There are a number of DIY's out there:

- Cut the spring.

- Slightly shave the rim's lip so it gets smaller in diameter.

- Change the tire to a thinner profile.

- Visit christianmingle.com and simply choose one that best matches the weight difference and install on the corner that's too high. Install takes about 30-45min depending on how fast you are at duct taping.

The list is neverending. You can find more at go-ratchet.com

[Twixboy]

Originally Posted by UntzUntzUntz

There are a number of DIY's out there:

- Cut the spring.

That didn't work. My rear spring was already broken before I replaced all 4 springs and the side to side height variance was the same.

Originally Posted by UntzUntzUntz

There are a number of DIY's out there:

- Visit christianmingle.com and simply choose one that best matches the weight difference and install on the corner that's too high. Install takes about 30-45min depending on how fast you are at duct taping.

I don't like this idea either because it will add too much weight to an already heavy car.

[dc_wright]

The TIS indicates the tolerance is 10mm for ride height at the rear plus 10mm side to side with the nominal load of 68kg in each of the seats, 28kg in the center of the trunk, and a full tank of gas.

An online version of the TIS is available here. http://translate.google.com/translat...m%2F&sandbox=1

[Twixboy]

Originally Posted by dc_wright

The TIS indicates the tolerance is 10mm for ride height at the rear plus 10mm side to side with the nominal load of 68kg in each of the seats, 28kg in the center of the trunk, and a full tank of gas.

An online version of the TIS is available here. http://translate.google.com/translat...m%2F&sandbox=1

Wow, thanks for the link. So maybe my frame is not straight? I should take it to a body shop to check it for me then.

[inTgr8r]

Originally Posted by Twixboy

If I replace the existing rear driver's side 5mm spring pad with a 15mm spring pad that will even out the rears. How would this affect handling, if one side has a 15mm spring pad and the other side has a 5mm spring pad? What I'm wondering is what's more important - the ride height from side to side or that the springs compress evenly. Should I just leave it alone?

When you corner balance a car with coilovers all four corners are at slightly different heights.
You then do an alignment which sets the car true at these differing heights.



You can do some shimming of the springs, but this will change corner balancing.
In addition to using different spring pads at the rear, you can also shim the front strut up (the diagonal opposite corner to the higher rear).

Unless you put the car on some CB scales you cant tell if the visual height changes correspond to where the corner balancing should shift.
You could be adjusting corner weighting in the wrong direction.
For street, it shouldn't be that big of a deal though.

The main thing is to do an alignment after you have played with height adjustments.

[dc_wright]

Originally Posted by Twixboy

Wow, thanks for the link. So maybe my frame is not straight? I should take it to a body shop to check it for me then.

There's really no such thing as a flat poured concrete floor, so that plays into the way you measured. Before you panic, you need to go back and measure the way the TIS describes from the lower edge of the arch of the fender to the lower lip of the wheel, and you need to do that with the recommended weights in the car.

[Steeler]

Originally Posted by dc_wright

There's really no such thing as a flat poured concrete floor, so that plays into the way you measured. Before you panic, you need to go back and measure the way the TIS describes from the lower edge of the arch of the fender to the lower lip of the wheel, and you need to do that with the recommended weights in the car.

^ this
I would be more inclined to pick a mirrored point on the chassis, say the 2 bolts that attach the rear bracing to the underside of the rocker panels and measure there to the ground
Measuring the wheel lip to centreline of the rim and tire is what I use to gauge height differences