W211 E500 Transmission Oil Wick in to control unit

[ama singh]

Hi All,

I've been doing a transmission oil change and found oil pouring out of the transmission electrical connector as I unplugged it from the transmission.

Car drives VG with no issues with gear changes, maintenance job - this will be the second fluid change on this car, ~90k miles since last transmission oil change.

I decided to pull up the carpet to get to the control unit and found transmission oil has managed to find its way to the control unit.

I'm in the process of cleaning up all the wires and connectors with electrical cleaning fluid/spray whilst cleaning up the control unit.

Has any one had similar experience and have they opened up the control unit to clean it out? would be grateful for some guidance?

 

[LostKiwi]

Quite common. Use switch cleaner to flush it out (switch cleaner is non conductive, contact cleaner may not be). Do not use WD40 anywhere near any plug seals as it causes them to swell. Allow to dry before reassembling.
Change the seal on the gearbox connector to stop it happening again.

 

[ama singh]

New plug came with the transmission service kit. I've washed the transmission side electrical connectors down with Holts eletrical contact cleaner spray to remove and degrease all of the oil - this end is pretty straight forward.

I'm just trying to cleanup the oil that's dripping out of the transmission control unit and all the wires under the passenger foot well before re-assembly, will leave it to air for a few days before I re-assemble.

Are the transmission controllers programmed/coded to each vehicle or can they be interchanged just in case I have issues after re-assembly?

 

[ama singh]

All back together again and seems to be running VG - looks like i was lucky to catch this before it damaged the transmission control module.

Would encourage others with auto W211's to remove electrical connector plug to transmission and make sure its dry and free from transmission fluid.