Front end tire wear - Sprinter 3500 EXT

[kaylorsan]

There is a lot of info on this on other forums, but I didn't find much here.

I was experiencing heavy wear on the outside edges of my front tires. So much so, that I changed then out at 10K miles. Long story short is that the alignment specs provided my MB probably are not the best for my particular setup/application. Via others recommendations, I set my alignment camber at zero degrees , rather than the positive camber that MB recommends (I believe it's 1.0 - 1.5).

I also installed somo springs to help with handling. More info below...

If you are having outside edge wear issues, your alignment may be at fault. Note that I had mine checked 3 times (twice my the MB dealer) and all times it was 'in spec'. Unfortunately, the spec wasn't applicable to my situation.

FWIW, I run all of my tires at 61 psi.

Below is my post to the other forum (sprinter-source.com)

-Kaylor
2012 interstate 3500 EXT Lounge
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Thanks to this board,I believe my front tire wear problems are now fixed. An alignment to zero degrees camber seemed to do the trick. At 10K miles, I had bad enough wear on the outside edges that I bought new tires (Michelin LTX M/S2) to replace the Continental Contis.

I went to a local shop in San Jose, CA (Ross Truck and Equipment Repair 408.292.1464). I took with me a set of camber adjusting bolts from Upscale Automotive. The team at Ross really liked the functionality or the bolts. They said it made the job super-easy.

My pre-alignment figures were 1.5 degrees (drivers side) and 1.25 degrees (passenger). Post alignment was 0. I can't recall what the Toe was, but it was reset. I have since put about 1000 miles on tires (we are on a road trip). I'm getting even, consistent wear across the treads.

I should also note that I installed Sumo springs (front and rear) before my trip. They have made a big difference and I am quite pleased with them. In the past, I put adjustable Konis on the rear as well as a bigger sway bar (both from Upscale). They made a big difference, but the front end was still a bit soft. The front sumos seemed to fix that. The rears seemed to address rear end sag (I have the extended sprinter, 24+ feet). Overall, the ride is much more dampened over bumps, in high winds and taking off-ramps. I was going to go with Koni struts in the front, but couldn't get them installed in time for my trip. The sumos are super easy to put on; especially the front. About 5 minutes per side. The rear installation is easy also, however there is just more stuff in the way to deal with (ie, my generator and lower ground clearance).

Once again, thanks for everyone's input on the alignment specs.

[David M]

Thanks for posting Kaylor. I'll keep this in mind!
David

[russ240]

I have the same experience with the front tire wear with stock alignment. I ordered the front Koni's and the adjustable camber bolts at the same time. My tech found that installing the Koni's alone gave him enough adjustment to take the positive camber out without having to use the adjustable bolts (I believe the mounting holes of the Koni's have some adjustment range while the stock struts did not). My tech's opinion was that the shank diameter of the adjustable bolts looked awfully puny compared to the stout stock bolts and since they were not needed he opted not to install them.

[kaylorsan]

Originally Posted by russ240

My tech's opinion was that the shank diameter of the adjustable bolts looked awfully puny compared to the stout stock bolts and since they were not needed he opted not to install them.

Which bolts did you use? I've seen some 'cam' looking bolts with a modified shaft that went in the lower holes. The ones I installed were really just bolts with an offset washer welded to the head. They went into the upper holes. There is a protruding feature on the suspension arm near where the bolt installs. By rotating the bolt, the attached offset washer will hit against it and provide a bit of controlled adjustability based on the amount of rotation applied.

I did not see the original bolts that were replaced, however I can't imagine they were much larger in diameter than what I installed.

Are you happy with your Koni struts? Do you feel the 0 degree alignment solved your tire wear issue?

[russ240]

We put the stock bolts back in but the ones that we did NOT use were cam looking and came from Upscale (Sprinter Store). I looked at them vs the stock ones at the time and agreed with the tech's opinion that the shank was much smaller, but that was some time ago so I can't recall exactly where they went or how the adjustment was made. If I get under the bus again I'm sure it would jog my memory.

I am very happy with my Koni's. The rears went on first and made the biggest difference in sway control over low speed, side to side oscillation (exiting driveway aprons at an angle for example) but overall the Koni's definitely provide a more stable ride/handling, well worth the money in my opinion.

As far as the tire wear problem, I do believe that getting rid of the positive camber has helped tire wear, but I've only put about 5k on the new tires (Michelin) and the original conti's did start to look shabby until I got to 10k IIRC so it may be too soon for a definitive answer. So far so good at any rate.