87 300 Impossible to Align! - PeachParts Mercedes-Benz Forum

bozemanbiofuels · #1 10-02-2007, 04:23 AM

This is a 300d but I think the body is the same as the 300e so I'm posting this in both topics:

I've replaced just about everything on my 87 300d turbo, 210k, new rear shocks, most of the rear arms, subframe bushings, sway bushings; in front it has new struts, control arms, tie rods, steering arm and probably a lot more I'm not remembering. I bought the car at 204k with completely worn Michelin's and they were smooth and even as new, so I know the front end was fine then. Before they realized the subframe bushings were shot, they replaced the front end parts which made it worse. After the subframe bushings were replaced it didn't wag around in back but the front still had problems.

The alignment shop has tried about everything and it drives like I'm drunk (but I'm not!). The outside shoulders of the front tires are wearing, and it weaves like the front wheels are fighting against each other. We tried reducing the toe in and that helps but the adjustment fades after 200 miles. While it's up on the alignment rack they can't get the readings to change significantly while stressing the wheels in every way possible.

I feel like we either installed some faulty parts, installed some parts wrong, or have yet to replace bad parts. Any ideas from the experts? Could we have installed sport suspension parts by mistake?

mbdoc · #2 10-02-2007, 08:32 AM

On the W124 cars, the rear links & mounting bushings will allow the REAR to change.

If that happens you will constantly have to move the steering wheel to keep the car going straight.

MOST likely in the rear. Try watching the rear wheels & move the trans position from drive to reverse. IF you see a change in the positioning of the wheel in the opening then either 1 of the links OR a bushing is the problem.

You might try power braking in both D & R a few times to load the drive line.

bozemanbiofuels · #3 10-02-2007, 11:27 AM

Thanks, I'll try that, but what opening are you referring to?

I know there is one set of dog bones in the rear that I didn't replace b/c they looked fine, but I could have been wrong about that.

mbdoc · #4 10-02-2007, 12:04 PM

The wheel opening in the quarter panel. See if the tire gets closer to the front or rear of the opening as you power brake in D & then R.

Watch both sides.

bozemanbiofuels · #5 10-04-2007, 09:29 PM

Possible progress... and to report:
the dealer actually let me talk to the mechanic who aligns these cars. He said my specs (which I have from my local shop) sounded in the ballpark but he seemed reluctant to give me the mercedes specs. He claimed they need to drive the car and adjust them all individually so they don't have a rigid set of specs. Sounded suspicious but I couldn't twist his arm over the phone.

My specs are:
FRONT (we didn't go over the rear end)
Caster L 10.2 degrees, R 11.0
Camber L 0.0 degrees, R 0.2
Toe L 0 inches, R 1/16

After describing how it drives, he said the steering sounded stiff and to losen the set screw on the gear box, which I did and it loosened up a little. It still feels like it's hard to turn, so maybe the steering damper has yet to break in or something, he suggested to check the steering idle arm. By the way, the set screw for the steering box is reverse of american stuff - counter clockwise tightens it. He also said there really isn't anything special about aligning these cars and that basically any shop should be able to do it. That was a surprise and I don't know what to think of that.

The test drive produced more managable car, but it still jumps around in crosswind a little. At least it's better so maybe my whole problem is in the steering. I didn't notice much movement in the rear wheel positioning in the load test. I'll drive it some more and try not to make it handle better just out of sheer will power!

I really appreciate all the help from the forum. I posted the same question over in the diesel engine side at this link if you want to see what they came up with: 87 300d Impossible to Align!

Paul