stuffdogg

Hi all, I'm a benz noob and I could use some help,

I got me an 1985 300d. It Ran somewhat smooth with only a minor shimmy past 60mph with stock 14" rims and well used tires. I hated the stock look and needed new rubber so I got some 7x17" aftermarkets. Now I have this earthquake of a shimmy when I get to about 50mph and sometimes 60mph. It is so bad that the car feels like car is going to fall apart! It is strange because somtimes it wont do it and run kind of smooth all the way to 70mph and other times when it starts to shake I can tap the brakes or let off the gas and it will stop the major shaking and let me continue to accelerate.
I thought it was the balancing so I put the stocks back on the front and keept the 17s in the back. The earthquake went away but then I put the 17s that were on the rear onto the front and the 17s that were on the front onto the rear and the earthquake came back. I can stick my head out the window and acctually see the wheel shake from side to side! Because I had no shaking with the 17s on the rear olny, I don't think the problem is with the balance of the wheels.
Now my question: Does it have to do with the size and width of the wheels or is my problem going to be the suspension system or something else?
I don't want to be stuck with those ugly stock rims. Anyone have any ideas?

mleskovar

Did you jack up each front wheel and try to shake them top to bottom and side to side to see if anything is broken or loose? Could be the steering damper can't handle the extra weight of the rims and tires or it is broken, worn, or out of adjustment....don't know how the steering damping is done on your car.

stuffdogg

I did jack it up and shake the wheel around a little and didn't notice anything loose but I will do it again to double check. Stearing damper? Hmm, I have to look into that. Not sure were it is but I did notice today that when it starts to shake if i turn the wheel a little the "shake" seems to deminish untill I turn the wheels straight again. Could it be that the alignment is off but with the smaller wheels (less friction) it dosen't get to the point where it shakes. I think I will go get the alignment checked tomarrow. Thanks!

mleskovar

Classic worn steering damper symptom. Since most driving is done in a straight line the damper gets worn in that position. You said the wheels noticeably shake from side to side....does the steering wheel follow the shakes? If not, then something is loose in the steering components like tie rod links, pitman etc. Once again, I don't know where, or even if there's a steering damper on your car.....maybe someone can chime in here.

stuffdogg

Ok, steering damper (shock) was 80% of my problem. It was totaly worn out. I spent $60.00 on the part and installed it myself In about 15 min! Wheels are balanced well. I use a local guy who has good equipment and I trust 100% and has perfectly balanced my wheels for years. I still have a slight shake that a can feel in the steering wheel at 60mph but nothing like It was before. I think I may have another steering or suspension component worn. Thanks for the help guys and please feel free to continue this discussion with any more suggestions.