722.9 E320 Gearbox Fault

[Alfie6447]

Hi guys, new to this forum, but ive got quite a major problem with my E320 2006.

When in park the gearbox rumbles the whole car, put it into drive and it goes, but put it into reverse and its there again. This rumble has only started since I had the tranny oil and filter changed.

The reason I had it changed was because the box was having trouble shifting gears, it would hold gears, be in drive but not move and just rev up. These problems are still happening.

The car has done 110,000 miles, but the engine is strong and ive read that these boxes are pretty indestructible except for a few things. The rumbling, to me almost sounds like a bearing has gone, its worth mentioning that there is also a whine coming from the box at around 50-60 mph. I know its definitely not wheel bearings as they have been recently changed. Also not tyres as they are new.

Bit at a loss with what I should try or check. I know the tcu has a habit of failing but would that cause the rumbling as well.

Any info is greatly appreciated.
Alfie

 

[kid-jensen]

Unfortunately, in changing the transmission oil, you have already performed the only "cheap" fix, everything from now on will be expensive.

If the car is worth spending money on, it's best to make sure the mechanics know what they are doing and are not just throwing parts at it, or educating the apprentice at your expense.

Look on here for recommendations of indys in your area and get a diagnosis that you can be confident with, then proceed from there...

 

[AndrewOl]

The electronic control unit (TCU) can cause problems with these boxes. Can be repaired with exchange units from MB at not too much eye watering amounts. If the TCU is acting up the gearbox usually goes into limp mode but can be reset by cycling ignition. Starts to happen more often as time goes by. No fault message but codes are stored that can be read with star system. Find a good independent mb service centre with star as before changing anything a proper diagnosis is required. My 2006 GL TCU went after changing the transmission oil and filters.

 

[Stevie777]

A shot in the dark this, might be the rear gearbox mount rubber failed, around £80 and 45 minutes work at any good garage (need a lift).
Symptoms sound similar to ones I had when mine went, same gearbox, common fault.