W123 alignment specifications - Page 2 - PeachParts Mercedes-Benz Forum

Stretch · #16 12-10-2015, 11:47 PM

Quote:

Originally Posted by NoSparkNeeded

I had both my cars set up by the dealer. Both wear on the outside front tires.
What setting needs adjusting please? I let the dealer do it at increased cost
for a reason I read here, something about a "spreader"?? whunter posted
something years ago about that. What should I tell the mechanic about outer
front tire wear? Do I need to rebuild the front ends?

If there's any doubt in the condition of the parts you need to check them.

Trying to adjust worn suspension is more often than not a waste of time.

rocket88 · #17 12-11-2015, 09:10 AM

Quote:

Originally Posted by BillGrissom

I would first verify toe-in. With a helper, use a tape measure to measure across the front tires fwd & aft sides. Fwd track should be 1/16 to 1/8" less than aft (without a spreader bar). Even quicker check is to lay a 4" straight edge along the front wheel and sight at the rears. You should sight ~1/2" off the rear on both sides, with the steering centered. FWD is easier because your sightline should fall on the rear tire.

But, whenever I had wear due to excessive toe-in, the inside edge of the tires wore. Toe-out cause wander, so doubt you have that. Your problem may be excessive positive camber, i.e. tires leaning out at the top. Should be very visible.

As I read the published MB W123 toe in: they say 3mm +- 1mm, or about 1/8 in for each wheel, with spreader. Which I do not use. So about 6mm for both together.

I too measure distance between front and rear of tire surface using tread grooves as the measuring point. If MB specs given are for the rim, surface of the tire will be a bit more. Easy to calculate with trig functions.

I don't have the patience, discipline for the string / box method. I used two 8 foot long pieces of 1 by 2 wood , use them as a strait edge... placed, balenced stable on a box placed adjacent to the front door, so they touch each front tire front and rear at height of center, that projects the orientation of each wheel along the body. just below the door

Adjust toe of each wheel so those lines are symetrical along each side. Then adjust each side the same amount to achieve desired toe in.

That is also the time to center the steering wheel if you care to,

Instead using measuring tape for side to side distance at front and rear points on the tire I use a 1 X 2 wood stick marked for distance, cabinet makers call it a story pole, mark front distance first, then place the stick at rear supported on any object of suitable height. Or start at rear and adjust to bring front Always adjust each wheel the same amount to sustain symetry,

each wheels toe the same amount to achieve chosen greater distance at rear. I'm using 3mm for each side, so about 6 mm total.

cfh · #18 12-11-2015, 11:56 AM

Centering the steering (by replacing the drain plug on the bottom of the steering box with a bolt that is a little longer and ground to a point) is a good idea because the turn signal cancel device is operated off the steering column instead of a tab or stop on the steering wheel itself. If, after alignment, the steering column ends up off-center, then the turn signal won't cancel properly.