Wheel Alignment - PeachParts Mercedes-Benz Forum

ffgb · #1 07-31-2016, 12:27 AM

I just rebuilt the front end on my 1983 300d. I replaced the front shocks, ball joints, control arm bushings, upper control arms, tie rods, drag link, steering damper, and guide mounts. When I replaced the tie rods and guide mounts, I measured the old ones and adjusted the new ones as close to length to the original ones. I then went to get an alignment. After the alignment, the tech said that very little adjustment was needed and now everything is within spec. He did say the car pulled a little to the right, so he swapped the front tires to see if that corrected it, but it didn't. I don't know why it pulls slightly to the right.
Also, the entire braking system, front and rear is brand new, along with new front bearings. The tire are michelin brand and only have about 5k miles on them.

I don't think the tech adjusted the guide mounts because he didn't know how. I don't know if the guide mounts make that much of a difference when an alignment is performed???

I am in the SF Bay Area, if there are any recommendations on an alignment shop that actually know's how to do a front end alignment on older mercedes and know's how to correctly adjust the guide mounts, please feel free to respond.

Thanks!!!

Stretch · #2 07-31-2016, 01:43 AM

Have a look in the forum's good shop section. There might be something there.

There is no way on earth any car should drag to the right after it has been to an alignment shop. (Well with out a decent explanation from the shop)

Sugar Bear · #3 07-31-2016, 11:39 AM

IIRC the adjustable rod from the guide mount is the caster adjustment and would make a difference in drifting/pulling. I cannot see why a tech would not adjust it, it is simple. Perhaps it was already in spec.

That being said, be very particular in selecting an alignment shop because some settle for within spec while others only settle for right on spec. When the alignment is precisely dialed in the difference is significant and it holds for a long time. My best success has been with a long established frame shop that does alignments; but, it is about 3,000 miles from SF. Look for a frame shop that does alignments in your area that appreciates vintage cars.

my123ca · #4 08-01-2016, 12:02 AM

Quote:

Originally Posted by ffgb

I don't think the tech adjusted the guide mounts because he didn't know how. I don't know if the guide mounts make that much of a difference when an alignment is performed???

Thanks!!!

If you measure the length from rear to front axle, usually the side with the shorter length will pull to that side. Find a shop that can adjust your caster. Just had an alignment last friday. The shop didnt use any computers or lasers. Showed them factory specs. Right side caster was off 15 min. Got that fixed. Drove home, steering was steady but my tires are new so i guess only time will tell. Previous tires didnt last 10000 miles. Tires wore out on the outer side. All new parts underneath.

BWhitmore · #5 08-01-2016, 12:14 AM

There are several very good MBZ repair shops in Burlingame. Give one a call and ask for a recommendation on an alignment shop. Nick's Mercedes in Walnut Creek is also good.

Junkman · #6 08-01-2016, 06:43 PM

I would ask the tech to have another go at it. There is enough adjustment on these cars that compensations can be made so the cars drive straight. Any modern alignment machine will indicate whether there will be a pull.

Also, look in the FSM for details. Changes in caster case camber changes and vice versa. The FSM has approximate amounts. I had one tech chase his tail for hours before giving the car back with a note "car can't be adjusted". He meant "adjusted by him". The next guy got it spot on.

Also, ask for the final alignment specs for your records. Note that the tech can give the heads a bump to make it look like the car is in alignment. Hopefully yours won't but one shop demonstrated how easy it is and said that it was common.

BillGrissom · #7 08-02-2016, 05:54 PM

In my experiences, pulling to one side was caused by a tire, but he swapped yours and no difference.

One fairly easy test you can do is support the front on the frame rails and at idle see if the steering box tries to self-steer. My experience there is with old Chryslers where one can tap the spool valve housing to center it so no self-steering. I expect the M-B boxes have a similar tweak, but never dealt with it.

jbach36 · #8 08-02-2016, 11:29 PM

It might not be the best alignment, but I get an alignment whenever I want, and I can only go to the places who have someone who know how to align a Mercedes.

I bought it maybe 5 years ago and it was a great purchase. I get the car aligned maybe twice a year. It beats paying $50 at a specialty alignment shop each time.

iladelf · #9 08-05-2016, 10:12 AM

Here's something interesting (DIY alignment), which may or may not be helpful in this case, but I'm guessing it could also be good at checking an alignment shop's work.

Mercedes DIY Alignment

ROLLGUY · #10 08-05-2016, 06:21 PM

I don't know why, but it seems that my usual alignment shop only adjusted the toe on the last car I brought in (1982 300TD). I replaced all the bad parts (ball joints, upper and lower bushings) and put the adjustment bolts exactly where they were (marked them). The tech said the camber (adjustment of lower control arm) was right within spec, and the caster was not adjusted, only toe. I asked why, and he said there is never enough adjustment in Mercedes Benz's, and that the difference between right and left ("spread" he called it) was within allowable spec. I don't understand why this shop (and now others that I am finding out about) only adjust the toe and call it good. That is ridiculous! I am looking for another alignment shop. Hopefully I can find one that will adjust all three angles, and not just the one......Rich

ffgb · #11 08-06-2016, 11:26 PM

Everything is in spec which is great, that is what I want, that is what is expected. But if the car still pulls to the right a bit, I know you can still adjust the alignment and then have the car pull to the left, and also do the adjustment then have the car steer straight. Having the alignment within spec means you will get correct tire wear, having the alignment with spec the correct way will give correct tire wear and your car steering straight while driving down the road. I am going to find another place because it seems the tech at this place cannot problem solve other than what the factory says what the specifications are.

Stretch · #12 08-06-2016, 11:39 PM

Quote:

Originally Posted by ffgb

Everything is in spec which is great, that is what I want, that is what is expected. But if the car still pulls to the right a bit, I know you can still adjust the alignment and then have the car pull to the left, and also do the adjustment then have the car steer straight. Having the alignment within spec means you will get correct tire wear, having the alignment with spec the correct way will give correct tire wear and your car steering straight while driving down the road. I am going to find another place because it seems the tech at this place cannot problem solve other than what the factory says what the specifications are.

If the car is pulling one way or the other then I don't care what a computer says - the set up is not "in spec". This sounds suspiciously like user error: the problem with computers is => rubbish in == rubbish out.

ffgb · #13 08-07-2016, 12:44 AM

Yup, I agree

Stretch · #14 08-07-2016, 12:06 PM

I can post up a link to a DIY alignment if you want - but there aren't many takers as it is seriously labour intensive

duxthe1 · #15 08-07-2016, 12:46 PM

These older cars are a dream to adjust, because they are actually adjustable. The newer cars with the camber / caster bolts and their "close enough" approach is pure rubbish.