Underlook

Hi All,

2010 GLK350 with about 110kmiles (175k km).

Works well but has a driveline shudder as light to moderate power is applied. No issue when heavier power applied.

Had flex discs and Center bearing replaced with no significant improvement.

When explained to local independent shop they said may need transmission fluid change combined with a procedure to do tight turns to try to work the clutch discs in the transfer case, to try to clean them up or scuff them or something.

Has anyone heard of this? Wondering if I should try the transmission fluid change or park the car until I can have the transmission removed and fixed. Seems like a silly problem for such an impressive machine with a great engine and transmission.


Any thoughts appreciated. Cheers!

PS. Rear diff fluid just changed and front diff change pending. Front driveshaft seems fine.

Odd Piggy

Shudder can be a symptom of worn out transmission fluid. When was the transmission fluid last changed? It should be done at 60k miles.
Personally, I would opt for the fluid change before removing the transmission. The transfer case shares fluid with the transmission on all 204 chassis. The indie shop’s suggestion could be the solution.

habbyguy

The torque converter can also cause a shudder that might fit the OP's description. The fluid change would be my first recommendation (almost always for most transmission issues) and next I'd try a tube of Lubegard ShudderFixx (sic). It's designed to help with torque converter shudder.

If it is actually the rear output shaft clutch / planetary gear, the good news is that repairing it won't be TOO big a deal. You'd have to drop the splash guards (to get to the center support bearing) and rear propshaft, but then the rear "slice" of the transfer case can be removed, and the planetary gear assembly removed and repaired. You will have to buy a new "hexabular" bolt (it is a stretch-to-torque bolt that's used to set the preload on the clutch).

Underlook

Thanks for the info guys. Nice to get the 2nd opinion on the transmission fluid change. I will try that first and fingers crossed.

Dealer confirmed car had the only transmission fluid change recommended by Mercedes which I believe was 60k km. So probably overdue.

Thanks again!

Underlook

Just to close loop on this thread, transmission fluid change went well. Used fluid looked good and no significant metal on magnet.

After the change there was immediately no significant improvement in the “shudder” felt in the transmission. However after driving the vehicle intermittently for a few months and doing some tight turns regularly in both directions, happy to report that the issue is totally gone!

Biggest problem may have been not enough use of the vehicle, not enough tight turns and need of a transmission fluid change.

Thanks for the assistance!