87 300d Impossible to Align!
 

I've replaced just about everything on my 87 300d turbo sedan, 210k, new rear shocks, most of the rear arms, subframe bushings, sway bushings, coil springs; 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 but it wagged around on the highway badly. 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. 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? Thanks in advance...

Could it be a bent chassis? Accidental or otherwise, your list indicates that you have changed all parts pertinent to alignment and yet you are not even coming close to a ballpark figure, how about a body shop with laster alignment equipment has a good look at your 300D body.

Should have gone to the dealership for an alignment. That is where I would take it now.

They aren't that hard to align compared to other cars, something is either wrong with the alignment tech or the parts you installed. It sounds like it's driving like mine did after I installed tie rods and totally ****ed the alignment up. Any little dip in the road and the car would want to move into another lane. After I took it to a standard alignment shop and got a 50 dollar alignment, all was well again.

What kind of tires did you put on it?

My 115 is picky about tires, my 123s are picky about tires and I'm about to discover how picky my 126 is about tires. My experience is that Mercedes simply don't drive for squat with cheap tires.

Thanks. As for bent chassis, it has only been driven by me since I bought it and that's when it was fine in the front end and the tires were all worn evenly.

The shop is the most trusted alignment shop in town, but they are not familiar with benz - nearest dealer is 200 miles away. I could try a different shop here, at this point what's another $50!

I put top of the line Toyo tires on it, and last winter was running Toyo studdless, both of which I've used on other cars. The studless tires are like driving on pencil erasers and given that both sets drove the same I'm not suspecting the tires.

I'm not talking about a little wander here and there. If I'm going 70 and there is a breeze or slight truck ruts then I have to work full time to stay in my lane. The steering is tight but I don't think it would be the cause. Maybe the steering damper is defective even though it's new? All the parts were from mercedesshop. When it's aligned to the specs in the book it's even worse, so we've been reducing the toe in.

That alignment shop doesn't know what they are doing.

What you describe is a grossly out-of-spec toe-in.

It sounds to me like your best alternative to solve the problem is to go somewhere else. The dealer will be expensive, but should be able to do the job correctly, and on all four wheels.

Have you checked your rear wheel control bushings?

Ken300D

oh yea... see thats the thing..every other alignment shop that does domestics say they can do a Benz. They "compensate" for not having the spreader bar... wrong.. you can't compensate.

plus Mercedes uses a completely different system for aligning.. weird ass mirrors hanging off the wheels. notice the small holes between the lugs...


fess up.. take a weekend off and go to the dealership..

plus they gurantee their work. hell they let me borrow a car for the 2 days that they had my car... pretty fun driving a C class for 2 days

Advice taken. The most expensive way is what I've been doing, which is replacing the car one part at a time.

I'm looking thru all the order confirmations and there are so many bushings that I don't know if I've replaced the control arm bushings, inner or outer. They keep prying on everything and saying it doesn't have excessive movement, but then they said that of the subframe mounts too.

Thats the problem. I used one of the best general tire/alignment shops around and they didn't get my SDL right. The dealer could. You need a spreader bar for starters.

I bet you are in Montana... beautiful country out there, but it SURE is a LONG way between towns... excessive wandering can be caused by a large # of things. caster too low, toe in, steering box worn, tie rods... ya gotta go to a BENZ capable shop to have it really checked out.

I know this may sound stupid. But have you checked the tightness of the front hub bearings. If they are loose they will give you a sloppy front-end. I hope this helps.

As for the shop, they did do a fine job on my 84 300SD, which I know is simpler but does that lend any logic to their abilities?

I haven't checked the front hub bearings but if they were loose wouldn't it show when they reefed on it while it's on the alignment rack? Never hurts to check, though.

Where can I get the official alignment specs to compare with what they're using? I have the sheet that lists what everything is being set to if anyone is interested.

If they dont have the spreader bar and the load compensators I dont think they can properly set it.

Just one bad bushing on one end of a rear link will cause a W124 to wag around like it's drunk. Check for fore-and-aft movement of the rear wheels, indicating a bad link, before you do anything (else) drastic. Notice my signature - I've been through this.