The Shoeman

I have a longer post about my car here here

So, I took my car on a cross country trip at speeds of roughly 95 mph for quite some time (legal limit was 80 mph but the general traffic flow was 95 mph or faster) so the car was in the low position while driving. I have my car's suspension set a bit lower for it's 'normal' ride height through Star DAS, so at highway speeds, it's even lower.

I came home and noticed excessive wear on the front tires. These were brand new less than 2 months ago and I had an alignment done before I went on the trip.

I'm now thinking the weight of what was in the car coupled with the low ride height might have messed things up a bit the alignment. But, with the air suspension, if I put a lot of weight into the rear, the car would level out and fill the affected air struts. Without any issue.

I'm thinking....WRONG!

The front and the rear couldn't have the same parts wear out that would cause this type of wear???

Did I just get crappy tires? Does the low ride height coupled with the extra weight for my trip cause the wear to be significant on all 4 tires on my 4Matic?

Any help or thoughts would be great.

wallyp

That looks to me like much more wear, and much more localized wear, than would be expected from a camber issue. It looks to me more like significant toe-out wear.

I would get two 10' pieces of EMT (1/2" metal electrical conduit) and some bungee cords. Drive the car slowly forward on a level surface and let it stop without touching the brakes. Bungee a tube on the outside of each front wheel, with most of the tube going forward. Measure the distance between the rear ends of the tubes and the distance between the forward ends of the tubes. The forward ends of the tubes should be at least a little closer together than the rear ends - If not, then the wheels are toed out, where they should be toed in.

If the wheels are toed out, they will be dragged sideways on the inner edges of the tires, with results similar to those shown in the photo.

The Shoeman

Thanks for the quick reply. I will see what I find out this weekend.

I'm thinking the tire that I have shown in the first post, is a tire that failed due to the stresses I put on it. But, why would the rear tires have toe issues? They're just going along for the ride, aren't they?

All tires were new and the car had an alignment done. What would cause all 4 tires to have this wear that looks like misaligned toe?

Here are pictures of the front tires.

tusabes

Take it to mercedes for alignment

whoever aligned it didn't know what the heck they were doing

ItalianJoe1

The suspension could be worn, as the bushings age, the dynamic alignment (when driving) changes a lot, and the wheels will toe-out under load that you won't see stationary on the rack. That's one reason benz requires using a toe-presser bar to set front toe, to simulate some of that. On an older car with weak guide arm bushings, the toe settings can move out quite a bit and cause that wear.

The Shoeman

So as a follow up with what I found. Multiple issues.....

The front tires were worn because even though I had replaced the inner tie rods and the tie rod ends during a steering rack swap, I found one of the inner tie rods prematurely had some in/out play. This wrecked the front tires.

The rear tires were worn/destroyed because at some point during the trip the upper control arm's rubber bushing essentially fell apart. This threw the camber WAY OFF! And with the added weight of our traveling gear, the lower ride height the car is typically at and the even lower ride height while traveling at highway speeds, stressed the tires beyond their point of reliability.

I replaced rear upper control arms and new inner tie rod and got new tires (Michelin Premier A/S). Alignment will be happening tomorrow at my wife's new employer...at an Audi dealership (next to the Mercedes dealership...same owner)

Everything should be all set and driving straight by tomorrow night.