Front differential question
 

Was under the car (1991 300te 4matic) on the weekend to check the front differential fluid level. It appears as though there is only one fill/drain plug, a 14mm screw. Is that correct?
Thanks,
Jamie

Incorrect.

On a 4matic the differential is INSIDE the engine oil pan....its lubed by engine oil. So the fluid is changed every time you do an oil change. As long as the engine oil level is fine, then the diff is fine. :D

That 14mm bolt you found is the engine oil drain plug.

well, thank you for the info. Since I have been using a topsider oil extractor for my changes I have never touched the oil pan plug. You are sure about this? My owners manual specifies gear oil.
J.

The rear differential does use gear oil. 75w90 synthetic is ideal. If you take a good look underneath you can see that the front drive shaft and the two drive axles go into the engine oil pan.

nice.
thank you.

It's been a while since I had my '91 4matic, but I believe that the differential is separate from the engine sump. The RH front axle does go through the sump however.

Unfortunately, I never changed that fluid, dealer did it for me (or charged me for it anyway), so I don't know how it is changed.

The front differential is different to the engine oil on a 4matic. Today I checked the front differential fluid, lots came out - indicates a problem... Anyways, I refilled it to the lip of the plug as per instructions, will test drive tomorrow.

Interesting....I guess I need to look even closer next time. :D :eek: