Still pulling after front end rebuild & alignment - PeachParts Mercedes-Benz Forum

ytmtnman · #1 03-13-2013, 06:25 PM

1983 300td

Alignment done after I replaced all wear components on the front end with the exception of the idler arm and center link. Not much slop in the steering box (wheels move almost immediately with the steering wheel). No brake drag (new calipers, pads, rotors, bearings with correct end play). Correct tire pressure. Swapped tires to check if the pull followed the tires.
The pull follows the crown of the road. In the right lane it pulls right. In the left (wrong side of road!) it pulls left. In the middle it wanders and pulls in different ways like a drunk.
I am thinking of bringing it back to the mechanic to realign. He seemed trustworthy, but I did not get a readout, and forgot to ask. Before the alignment the pull was present. The Mechanic told me before hand that he may not be able to get it perfect and I said "that's ok". I have always had good luck with alignments after a rebuild.
What should I be looking at?
Thanks.

Doktor Bert · #2 03-13-2013, 07:38 PM

A pull is almost always a bad tire. Swap them right to left. I had a set of tires once that induced a bad wander too. Toe out will cause a straight-line wander.

Most shops can store the printout and he may be able to produce it for the asking....

ytmtnman · #3 03-13-2013, 08:03 PM

Quote:

Originally Posted by Doktor Bert

A pull is almost always a bad tire. Swap them right to left.

Done...still have the problem.

BTW....welcome back. Haven't heard from you in a while.

anghrist · #4 03-13-2013, 09:14 PM

Odd...

... How is the rear end suspension and alignment?

A bad tire on the front would make a noticeable pull to one side of the other, a bad tire on the back would likely cause more of a list or drift to one side.

Is the ratio of pull a progressive effect?
Does it turn like a tractor?

These would indicate really bad camber issues.

Most shops do not have the W123 apparatus which replaces the shock(s) for properly aligning the front end. I'm not sure how necessary this is for a 'good enough' alignment though.

Zulfiqar · #5 03-13-2013, 09:24 PM

turn the wheels to the right - get someone to rock the steering and feel for movement of the ball joints of the drag link, also feel if the idler arm moves up.

Car wanting to follow the road to the extent that you have to countersteer it is a failed ball joint end in one of the 6 pieces.

ytmtnman · #6 03-13-2013, 09:29 PM

Quote:

Originally Posted by anghrist

Odd...

... How is the rear end suspension and alignment?
Is the ratio of pull a progressive effect?
Does it turn like a tractor?

I didn't mention to the mechanic to do the rear end too. I guess I am naive to what adjustment can be done back there. Can you clue me in?
Also, I am unsure of the meaning of the questions about progressive effect and tractor. Can you elaborate?
Thanks.

newtodiesel · #7 03-13-2013, 10:26 PM

Tie rods replaced?
I think a slight veer or wander to right when on rt side of road could be about correct, since the road is not level for rain run-off
Is it an actual "pull"?
Maybe calipers pads dragging?
Alignment can almost be done by eye/hand.
I personally have seen it done on my car with a good mechanic. please post you results and findings.

Stretch · #8 03-14-2013, 05:12 AM

Quote:

Originally Posted by ytmtnman

I didn't mention to the mechanic to do the rear end too. I guess I am naive to what adjustment can be done back there. Can you clue me in?
Also, I am unsure of the meaning of the questions about progressive effect and tractor. Can you elaborate?
Thanks.

There is no adjustment on the rear end of a W123.

(Well you can buy aftermarket eccentric trailing arm bushings - used to be able to get them from fastlane apparently - but this isn't standard kit for the W123)

Stretch · #9 03-14-2013, 05:15 AM

It sounds to me that the castor and camber isn't set correctly. You need some proof.

Having adjusted the suspension + tracking on my W123 I am absolutely certain that I can adjust it to be absolutely spot on. There is no reason why someone could not get it perfect if they knew what they were doing. It is just a question of time spent and effort made. Most commercial organisations are not willing to put in the effort - they call it uneconomical. (In my opinion for many places - not all - this is an excuse for laziness)

ytmtnman · #10 03-14-2013, 11:59 AM

I talked with the mechanic and he said he would rather give me my money back than to have another look at it. He said that it was probably due to a worn steering box, but I disagree. He said his 20 year old machine did not give read outs, and when I asked what spec he aligned to (MB spec or something else) he could not give me a straight answer. I think I'll take my money back and hope for the best at another shop.

Stretch · #11 03-14-2013, 12:11 PM

Good plan - make sure they have experience of doing older MBs and make sure they know what a spreader bar is.

JamesDean · #12 03-14-2013, 12:18 PM

Quote:

Originally Posted by ytmtnman

I talked with the mechanic and he said he would rather give me my money back than to have another look at it. He said that it was probably due to a worn steering box, but I disagree. He said his 20 year old machine did not give read outs, and when I asked what spec he aligned to (MB spec or something else) he could not give me a straight answer. I think I'll take my money back and hope for the best at another shop.

I would suggest going to the dealership.

That's what I had to do with my 124 300D. Just three weeks prior I took it to another shop, who said they could do Mercedes and had actually been doing my 190E (to my dissatisfaction really) and it was horrible.

The dealership was only $150. The other shop was $98. For the extra $50, it was well worth it. I plan on taking my 190E there as soon as I get the brakes all sorted out.

Doktor Bert · #13 03-14-2013, 05:18 PM

Quote:

Originally Posted by ytmtnman

Done...still have the problem.

BTW....welcome back. Haven't heard from you in a while.

Thank you,

New work has brought me much travel...

anghrist · #14 03-14-2013, 05:55 PM

Quote:

Originally Posted by Stretch

There is no adjustment on the rear end of a W123.

You are correct, but that does not mean that everything is ship-shape. I did ask about suspension, meaning, how are the links and bushings back there?

I believe that someone else mentioned the ball joints on the front end as well. Another likely place to look.

anghrist · #15 03-14-2013, 05:58 PM

Quote:

Originally Posted by ytmtnman

I didn't mention to the mechanic to do the rear end too. I guess I am naive to what adjustment can be done back there. Can you clue me in?

No adjustments to be made, just make sure all linkages are tight.

Quote:

Originally Posted by ytmtnman

Also, I am unsure of the meaning of the questions about progressive effect and tractor. Can you elaborate?
Thanks.

Meaning - Do you have to apply pressure (opposite of the turn direction) to the steering wheel to keep the turn-rate constant? Does the car want to steer more into the turn?

Farm tractors tend to have an appreciable amount of positive camber (tops of steering wheels are further apart than the bottom). This makes the tractor easier to turn since they usually only have manual steering and tend to have a great amount of weight on the wheels. It is fine for a tractor which may never go faster than 15mph, but it's downright dangerous for a car which routinely travels over 60mph.