Sagging front springs affecting alignment?

[IslandMon]

I just finished replacing both front control arms with late-style MB, new bilstein sport struts, 2 bump pads and new MB strut mounts. Also repainted sway bar and replaced bushings, painted front springs, and replaced both tie rods (center link and damper replaced a few thousand ago).
Brought the car in for an alignment, and dealer could not get front camber dialed into spec due to original front springs sagging. Said it could be brought into spec by pushing up on the car "helping the springs". Before and after report attached

Has anyone replaced their stock original springs with new for this reason? The car drives and feels great, but would consider replacing if there are night/day benefits.

 

[gsxr]

Re: Sagging front springs affecting alignment

I just finished replacing both front control arms with late-style MB, new bilstein sport struts, 2 bump pads and new MB strut mounts. Also repainted sway bar and replaced bushings, painted front springs, and replaced both tie rods (center link and damper replaced a few thousand ago). Brought the car in for an alignment, and dealer could not get front camber dialed into spec due to original front springs sagging. Said it could be brought into spec by pushing up on the car "helping the springs". Before and after report attached.

I don't agree with the dealer's diagnosis. Coil springs don't really "sag" much, if at all, although I've heard this many times over the years. Additionally, if the ride height a bit lower than normal caused that much alignment issue, every person who installed H&R lowering springs (or even AMG E60 lowering springs) would fail alignment. I think something else is wrong, but I don't know what exactly.

Has anyone replaced their stock original springs with new for this reason? The car drives and feels great, but would consider replacing if there are night/day benefits.

DO NOT expect night/day benefits. More likely you'll end up with a lightened wallet. Besides, if you currently have 1-pt or 2-pt front spring pads, you could raise the front end a bit by installing thicker pads for a lot less $$$. What concerns me is the right front caster pretty far out of spec. Ride height (spring length) generally has more effect on camber. Makes me wonder if the right front wheel kissed a curb many years ago?

On a side note, I find it a little odd there is almost a full degree of difference between rear wheel camber measurements. Rear camber is strictly a function of ride height (assuming nothing is bent or damaged); but you'd have to pull the coil springs out and measure the free length to see what's going on.

 

[FU2]

are you 100% sure that they are not broken or cut?

 

[Glen]

Might help diagnosis if you can measure ride height at each corner. This will tell us if the car is sitting normally or not.

 

[gsxr]

Might help diagnosis if you can measure ride height at each corner. This will tell us if the car is sitting normally or not.

Good thinking, Glen. When measuring, have the car on a flat surface, and measure as shown in the pics below. It's easier with stock wheels / center caps. Via the method shown below, most stock 500E's will be 13.75-14.0" up front and 14.25-14.50" in the rear. Full tank of gas vs half tank will change the rear about 0.25-0.50".

 

[IslandMon]

are you 100% sure that they are not broken or cut?

Not broken or cut, just had them out of the car and looked stock. Did not measure each one while they were out, but I could do it pretty quickly now that I have the spring compressor

Good thinking, Glen. When measuring, have the car on a flat surface, and measure as shown in the pics below. It's easier with stock wheels / center caps. Via the method shown below, most stock 500E's will be 13.75-14.0" up front and 14.25-14.50" in the rear. Full tank of gas vs half tank will change the rear about 0.25-0.50".

I will take these measurements at a nice new gas station in next week or so and report back.

Re: right wheel kissing a curb years ago, very well could have over the 130k miles that the car was not in my possession. I'll have to check the last alignment printout to see if it was similarly out of spec then

Thanks!