300SDL: both front wheels are worn on the inside
 

I am not an alignment specialist. So what is the reason for the worn rubber on the inside of the wheels of my 126?
Toe is incorrect? or what is it. Is there anything I could do myself to solve or ease the problem?
Martin

Seriously, just have MB perform an alignment/front-end check. Even on an old MB I wouldn't trust anyone else to align the car. Pretty involved when done properly.

If its not been done, probably time for control arms and ball joints. (then alignment)

Excessive toe-out will cause that issue. Too much negative camber will also cause the issue, but is much more unlikely unless the front springs are very soft and the body is several inches lower than stock.

You can check toe with a careful measurement (with a stick ruler) across the tires.

Take one measurement at the very forward edge of the tires. Take the second measurement at the very aft edge of the tires. The two measurements should be within 1/16". If the forward measurement is significantly larger (1/8" or more), the wheels are toed out. You can fix this in a half-assed manner by screwing the tie rod sleeves an equal amount on both sides so the wheels come in at the front.

It's not a perfect solution, but in your situation, it's better than nothing.

Hi Brian, thanks
I'll check toe in. I have done it before on another car. Toe-in is about 1mm difference per rim? I think I measured the rim edges before... at the string.
I had the feeling today the car pull slightly to right side on the highway...

TX mentioned ball joints and CAs. In fact my ball joints are both toast. I need to change them and CAs here in Oman. I started building tools, spring compressor! and tool for pressing in the new ball joints. (I have my MIG welder here) I have the spare parts on my shelf.

Werm,

Do what Brian said, to buy yourself some time (read: wearing out the tires completely). I would think once the front end components are changed, then new tires, then 4 wheel alignment (er....immediately after new tires).

Doesn't have to be an MB dealer, but a reputable shop that knows what they are doing. From my experience, the new alignment systems are pretty automated, but none the less, it's only as good as the person doing the work.

Just my .02

it means you need an alignment. take it to a shop. it's a lot less expensive than buying new tires.

I'm taking my car into the dealer tomorrow afternoon to have an alignment done. I had one done at Firestone recently and either they messed it up or didn't figure out the guide rod mount was bad on the driver's side. If you have a clunking sound when you hit the brakes, it is usually the guide rod mounts. Every time you brake, the wheels move back and I imagine that would wear the tires more.

Netagive Camber, lower control arm bushing?
http://www.peachparts.com/shopforum/diesel-discussion/327922-negative-camber-front-wheels.html

Some have had the Alinement done only to have it get messed up within a Year due to one of the Old Control Arm Bushing failing.

I had a 4 wheel alignment done on the car last Friday at the MB dealer. It turned out to be just under $200. Allen at Park Place in Grapevine, TX performed the alignment. I spoke to him about the car and explained what was happening and what I have replaced before bringing the car in. He performed the alignment and tightened my steering box as well. I am very happy with the results and the quality of service provided. He also said my camber was very negative.

I drove over 700 miles this weekend on a trip and I don't notice any abnormal wear on the front tires. I swapped the drivers side with the rear before going for an alignment.

Firestone can't center the steering wheel on a W126, so don't take one there if you care.

Wear on the inside would be caused by toe out. If toe was the problem.

Yep, I had it backwards.

Thanks.

Brian and Walgamuth

I had measured the toe-in yesterday with a kite string( string from rear wheel to front wheel. I put the wheel straight as much as I could (I couldn't figure out how to lock the steering gear box with the lock screw. I have the screw with cone in front but didn't find where to put it into the box. There was no plug where I could insert the screw).
I measured with a string and I had on both wheels a difference of roughly 2 mm (toe-in measured at rim edges). right side was 2mm difference, left side was 2.5mm difference. My steering wheel is pulling slighly to the right side...maybe the toe-in is not quite equal on both sides.
This means that toe-in is roughly 4.5mm (measured at the rim edge).

Assuming that toe-in set point is probably 1mm per wheel?? I measure double the toe-in.

This is not what I expected (I expected a toe-out situation with worn tires on the inside).

remember: I have worn lower ball joints, one worn guide rod and worn upper control arm ball joints. I'll replace these components as soon as I can.

I think there is hardly anything to do without fixing the worn out suspension members? What do you think?

Here is one question: Would you replace also the lower control arms? I have no evidence that they are worn but who knows?

Martin

Quite a while back, I replaced both ball-joints, all steering-joints, idler etc, and damper. At the same time, I had a 4-wheel laser alignment done at a reputable place, and two new tyres fitted on the front....

Within 6 months and 6K driving both front tyres were toast.:mad:

I did a front-wheel alignment (toe adjustment) myself with the old optical Dunlop gauge,--prob about 50 years old-- now there is no uneven wear on the tyres.

Just goes to show, 4 wheel Laser alignment isnt all its cracked up to be--most depends on the operator of the equipment!