Thump! low speed
 

I have a '90 300E 4mat with an ugly, new problem:

at very low speed ONLY, and ONLY if the wheel is turned left or right, there is is a loud thumping shudder, emanating from the centerline of the car. It feels as though the whole car is resisting/shuddering that motion...

To be clear, it's only at the sort of speed you get at parking, (very slow), and only if my wheels are turned at all. Straight back or forward, no problem. As soon as normal driving speed is assumed, no shudder...but I do mean shudder....

I guess I just have to keep driving above 10km/hr, and not park!

Seriously, it's not good. I only feel it if I turn the wheel either direction and either accelerate fwd or revrs...WEIRD!

Please HELP!

Me again...I should add it is a few "pumps", not just one..as soon as any speed is achieved...no more.

Do you hear the ABS motor pump? It could possibly be the start of a malfuntion in the ABS system. A sensor starting to go bad.

Mine does the same.

It's the bushings or the balljoints -or both that are worn out.

Freestyler

Thanks guys...

I think I might have a new clue, this morning the 4Matic dash warning is lit up...

Any thoughts?

So: bad news: the system warning light won't go off but good news: the 'seizures' have stopped.

Ok...I've done lots of searching around this (great) site and have found several not so subtle hints that the '90 era 4matic system is rather suspect...

My guess is that I have a problem that many others on this forum have reported, that the Transfer case has packed it in, but I'm only guessing....There's no obvious signs of leaking, but I would like to check the level of fluid just to be sure...anybody know how?

In the event that the system is kaput, can one continue to drive it as a 2wd vehicle? I have NO appetite to blow 5 large on a repair, especially if the car can operate fine as is...but I worry that I could be damaging something else that will result in a real problem down the road.

I know how to take the 4matic offline (test mode?)...should I or should'nt I?

Any wisdom appreciated>:confused: