Good point. You really need to check all of your alignment settings to diagnose the problem. Guessing won't get you real far.

Scott

I just rebuilt the front end and had an alignment done, so I am quite confident it is to spec, I was just hoping to add a hair of negative camber with out throwing off the rest of my fresh alignment.

The outer 1" of tread is where the tires are worn. No saw tooth pattern or anything. The wear did occur before my front end rebuild and alignment, but I really thing the wear is from hard cornering rolling the tire.

exactly what happened to me on my sd. I ate through a decent set of tires quickly. I just rebuilt the front and had it aligned. I also think it may be destroying them quickly from hard cornering, which is why im getting 15 inch wheels. 14 inch wheels are obsolete and its time to move on

What is the toe-in spec for the 123 cars in mm or inches (not degrees)? My front tires are wearing on the inside (worse on the RF). I just rotated the tires from front to back and don't want to wear them down prematurely.

Just because you have a wear problem doesn't mean you have an alignment problem. Just because your tires are wearing on the inside doesn't mean you have a toe problem. But since you asked, I am going to guess roughly 1/32 of an inch.

Scott

I just measured the toe-in. I don't have any! It's toe-out-ed by3/8". I couldn't find the spec in the owners manual nor the Haynes. Anybody know what the spec should be?

Don't take this the wrong way but are you sure that you know what you are measuring? Spec is 1/2 degree total toe for front wheels. If your car was toed out 3/8 of an inch there is no way you could drive it in a straight line.

Scott

The W123 front suspension is very finicky to align, every adjustment you make will affect every other measurement, it takes some time to get everything to come together, when I used to do alignments every day we used to hate to see a W123 coming.
That being said, it is impossible to just make a camber or toe adjustment arbritrarily without affecting everything--don't do it. Take the car somewhere it can be done right.
Also, I have seen at least two posts concluding that probably hard cornering was wearing their tires. It would seem obvious the solution would be to drive normally?!!

Scott,

Fair enough question since you don't know me. I've aligned toe-in's on all my cars using the tool I made (pics below) for many years and never had uneven tire wear issues. It's a simple, easy and cheap tool to make and is very accurate and repeatable. It is basically a fixed caliper with 2 push pins on the tip of each arm. A piece of masking tape is put on the rear of the front tires and the caliper pins is pushed through the tape into the rubber. As the pin is removed I circle the pin hole mark with a pen to make it easy to spot later. The car is pushed forward so that the front tires rotate 180 degrees and the the caliper in put on the front of the tire as shown. First put one pin on one mark previously made, then the difference from the other mark to the other pin is the total toe-in. It takes about 2 minutes to get a reading.

I adjusted the toe-in at the Home Depot lot and set it to 1/16" total toe-in. It was a PITA to loosen the outer clamp and the nut as it was pretty rusted in place. I sprayed it with lots of "Free All" and it still took a lot of work. The outer sleeve is slotted so it can be clamped securely but the slots allows more rust to develop. One end has a tappered slot with a nut forcing a bushing.over the taper. I had to turn it back and forth with a pipe wrench 1 degree at a time to break it free. Probably spent an hour laying on the ground and turned it about 1 turn.
http://i31.photobucket.com/albums/c3...083109_008.jpg
http://i31.photobucket.com/albums/c3...083109_006.jpg
http://i31.photobucket.com/albums/c3...083109_007.jpg

Looks like this method should work assuming (1) you have a steering wheel lock in place. If you adjust your tie rod without one, it will throw off all of your measurements. (2) You never jack the car off the ground. If you do, you need to roll it forward and back about 6 feet to settle the suspension and (3) everything on your tool is dead straight.

If all that is true and you've got 1/16 inch total toe you should be good to go.

Scott

I agree.

I couldn't disagree more. Castor adjustments will heavily affect camber and toe. Camber ajustments will heavily affect toe. Toe adjustments will have very little affect on camber or castor. UNLESS you are making major adjustments to any of the items they shouldn't affect the others in reverse. In other words, if everything else is aligned properly, a half a turn of the tie rod isn't going to throw your camber way off. If you turn your tie rod multiple times then maybe it will. However, a slight camber adjustment will throw your toe way off.

Easier said than done. Most alignment shops are staffed by lazy sob's who care more about getting your car out in 30 minutes than taking the time to do it right. I've easily spent 3 or 4 hours aligning my car to get it right. But I make sure my camber is dead on, not even a 1/10 of a degree off.

Scott

interesting tool... most use a simple pvc tube with a set of nail through them... how sure are you that the wood attached to the tool is dead on perfect and locked solid?
oh, there sure is a lot of rust on that poor car. where do you live?

John, please describe the PVC tube/nail and how it's used. The wood is luan plywood epoxied to the aluminum screen door frame strip. The whole thing is very light and stiff relatively, which allows it to hang on the tires like that and give repeatable measurements.
The suspension on this car has other issues which I will have to take care of. The toe in adjustment I made yesterday is to prevent ruining the 2 good tires rotated from the rear to the front. I should have checked the toe-in when I had new tires put on 15,000 miles ago. Being that it was not a daily driver then, I didn't check it and then forgot about it till I started having brake problems a few weeks ago and discovered worn front tires in the process..

a section of pvc, or metal EMT with a nail driven through it. some attach a yard stick to the tube, for measurements. at the alignment shop I worked at, they had a special tool with cast 90° ends on it for this. bottom line is you need perfect repeatable measurable marks on the tires. at the shop, we set the tool up on the front, spun the tires around to make a perfect line along the circumference of the tire, then brought the tool to the rear, and measured the difference. of course, you have to have all the weight on the car when you make the measurements, so using tape on the 123 tires is a good idea. at the shop, we never worked on any MB's... just about everything else though. had an alignment pit. with rotators at the end, drove out onto the rotators, made the marks, bottle jacks picked up the front end at the LCA's and we made all the measurements and adjustments.
with your tool, I'd attach a pair of squares to the wood, or something to VERIFY the wood isn't flexing or moving during your measurements.