B Marques

I see some grayish grease all over front diff and axles does anyone know what that is? Have never seen anything like that before.

ItalianJoe1

Silicone from inside the motor mount support arms. It softens and runs out with age.

B Marques

Okay good. Was worried I was going To have diff issues. Anyone do motor mounts? My 4 matic c class costs an arm and leg just in labor

ItalianJoe1

It's easier on the GL than on a C-class. Labor time is about half. The part that contains the grease is not the mount but the actual metal arm that attaches from the mount to the engine block. It's filled with silicone for noise/vibration reductions, but it won't actually hurt anything when it leaks out, at some point they stopped putting the filler in there, I've seen some without it, some only filled on one side, etc. It's a bluetec only thing I believe.

B Marques

good to hear. I'll pressure clean and leave it alone. Thanks for your help.

Callisto1

You don't specify which vehicle has the leak, but I'll bet it's your GL 350. They put special motor mounts in them to withstand the higher temps of the diesel, but after 5-7 years, they melt anyway and the result is a grey grease near the front diff which is on the drivers side. Presumably the pax side will go soon as well.
I assume the fluid in the motor mounts is meant to dampen vibration. Other more knowledgeable in the forum can opine on the wisdom of doing nothing. I chose to replace both mounts. Not sure the exact cost because I did the oil cooler at the same time. But $2000 +/- would be a ballpark for a dealer service just for the mounts.

And after replacement... I removed the plastic belly pan so more airflow gets to the engine compartment. Wish I'd done that 6 years ago.

drkennyle

I try to find the right forum for GL 450.
Any tips on how to change ambient lighting for door panels and dashboards for GL450 2014... Thanks in advance for the help.
Ken.