C200 W202 rear diff oily....

[LittleRestraint]

Hi all.

I did the front discs and pads on my car today, and whilst it was on stands I had a look around underneath. Everything seemed to look pretty good for a 17 year old motor, apart from the rear diff, which had a coating of thick oil, almost like grease in consistency, and gritty (no doubt from picking up crap off the road).


I've owned the car about 10 months but never checked the diff before, so it's probably been like it a while. There's no physical leak, or at least not a bad one, as it's never dripped on the drive etc.

Is it likely to be just a seal that needs doing? If so, how difficult is it? Should I change the diff oil? I'm going to change the flex disc soon so I figured I could change the diff oil while I'm under there if it's recommended....not sure about the seal though, as I'm a bit green.

There's no real whine to speak of, perhaps very faintly, but I understand that's fairly common on these cars. It's certainly not enough to make my ears ***** up, and I'm fairly paranoid about untoward noises

What's everyone's take on this?

Thanks for the help

 

[jasons]

Fairly normal to have an oily diff,my w202 was the same the oils comes from the breather which sits on top of the diff housing as the hypoid oil froths and foams about,they hold 1.1 ltrs of oil before you drain the oil make sure you can undo the filler bung as they can be very tight and brush some petrol around the breather to clean it up a bit,and fill until the oil starts to come out of the filler hole and make sure the car is level.

 

[LittleRestraint]

Fairly normal to have an oily diff,my w202 was the same the oils comes from the breather which sits on top of the diff housing as the hypoid oil froths and foams about,they hold 1.1 ltrs of oil before you drain the oil make sure you can undo the filler bung as they can be very tight and brush some petrol around the breather to clean it up a bit,and fill until the oil starts to come out of the filler hole and make sure the car is level.

Spot on, thanks a lot mate.

 

[4johng]

Hi ,

Apparently a lot of the diffs throw oil out of the breather , my slk 200 the same, when it checked the level it was well down , so it will need the oil dropping and refilling. However the MB oil ( 90) from MB is very ££££. On the slk forum it is well known that replacing the 90 grade oil with a fully synthetic 75 W 90 stops the over heating and therefore the breathing gassing problem . I changed mine 7 months ago and it has been good since. The synthetics have a high temp before gassing .

Regards,
Johng

 

[LittleRestraint]

Thanks mate, going to do the oil today I reckon, god knows when, or if it's been done in the past.