I've had my c6 for 3 months and noticed the left side sits lower than the right. The difference is 5/8" in the rear and 3/8" in the front. Has anyone had this problem or know a possible cause?

 

Where are you measuring from? The shop manual gives detailed info on how the ride height (trim height) should be measured... a special gauge is needed... someone recently posted the related pages from the shop manual here at the forum but I could not find them just now... search around, you may find.

Measuring from the body panels to the tops of the tires or to the ground is technically not an accurate way to measure since the panels themselves are not perfect side to side, etc. The GM trim height gauge, if I remember correctly, measures the relationship of the control arm to the crossmember it is attached to... no body panels nor even the outer steel frame of the car is used for proper measurement / adjustment of the trim height.

Regardless, if you wanted to, it's very easy to adjust the trim height. If you wanted the left side a little higher than it is now, you could crank the left side trim height adjuster bolts by about one turn clockwise then re-measure... and go from there. Just remember to drive the car a bit before re-measuring / re-assessing because these springs have a memory. Chances are you would not need more than one full turn on the left side, probably less... you may actually want to start with just a half turn clockwise come to think of it.

 

i wouldn't say mine is exactly even.

 

because you sit on the left, not the right

 

It's normal for it to be a bit uneven like that. Mine is even in the front, but not the rear. Like Vet said, the body panels aren't a proper reference point. They are not positioned perfectly with respect to the chassis. The proper measurement is the vertical distance from the bottom of the lower ball joint, to the axis that the lower control arm pivots at. I'd have to look up the specs though.

As for adjusting the ride height bolts... well, if you move one you move the other one a bit, via the sway bar. You also add some preload to the bar. You could try messing with it, but you'll never get it even.

 

Trim height front is 46 mm. Trim height rear is 122 mm. Maximum permissible variation is 6.35 mm.

Front trim height is measured from the lowest point of the ball joint to the centerline of the lower control arm forward mounting bolt. You can use a carpenter's level as a measuring jig in place of the J 42854 GM special tool. Just use it to extend a level line from the bottom of the ball joint over to the lower control arm bolt, then take your measurement.

The rear trim height is measured between the same points, and in the same way, as the front trim height. Again use your carpenter's level to extend the line from the bottom of the lower ball joint to the forward lower control arm bolt.

As others have said, measuring body panels to ground isn't a good way to determine trim height. Body panel fit is a lot more variable than you might think. There can easily be a half inch (12.7 mm) variation from one side to the other.

Of course you must do the trim height measurements on dead level ground, best to do it on an alignment rack. If there is a slope, it'll shift the car's weight and throw off your trim height measurements. It doesn't take much of a slope either, check the spot with your carpenter's level before proceeding.

Note that if you have 4 sets of scales that can each handle a quarter of the car's weight, you can set the car on the scales and adjust trim heights to equalize the weights side to side (remember that front to rear the front is supposed to be 1 percent heavier than the rear). This corner weighting will also accurately level out the car, but you might wind up overall higher or lower than if you do it by directly measuring trim heights.

Getting the trim heights set correctly can have a fairly dramatic effect on the way the car handles. My car came from the factory grossly out of trim height (it was too low and uneven side to side). After setting the trim height (with a weight equal to my own weight in the driver's seat) I could immediately feel the difference in the way the car rode and handled. Later, I raised the car a bit more to get better ground clearance, but I was careful to maintain the balance I had achieved by initially setting the trim heights to the factory correct values.

 

f55

 

How did you notice this?

 

Awesome Shopdog!! You're worth your weight in gold! Thanks for the info!

 

If this makes you feel better I have never owed a car that wasn't uneven ... seriously ...

I never noticed this until 2000 when I read a post on a bmw board about it (damn internet makes you realize the craziest things) and at that time I had a 330Ci ... it drove me crazy but then on every car after that I realzied no car is perfect ...

I think it is pretty cool on the vette you could actually adjust the height though it would drive me crazy to measure my car so i won't bother measuring it ...

 

Thanks for the help everone I think i'll try messing with it myself, It sounds straight forward.

 

I'm curious... What's the height adjustment range, higher and lower, from the stock factory setting that can be set?

Brad

 

I am Lefturn's neighbor and he asked me to verify what he was seeing. In his case it was pretty obvious by looking at the tires from the rear and seeing more tire on the right side.

 

Just look at the amount of thread showing on the height adjusters above and below the spring and multiply by 1.33. Typically, you can raise the car about 1.5 inches, or lower it almost an inch without cutting the bumpers (the rear has a more limited range than the front, but you want to adjust front and rear equally to maintain the designed 5 degree rake of the car). Realize that changing the trim height will alter suspension geometry. It is a good practice to have the car aligned after changing the trim height.