mrobinso

JUAN I wasn't referring to you when I referenced that thread. I was simply noting that in that thread there is a discussion of the MB Spec hypoid 85w-90 fluid versus any other aftermarket fluid, as well as the lamentation from a particular E320? owner who put 75w-140 in his differential and ended up with a viscous goo. Wonder whatever happened to his differential, it was never really clear when the thread died.

To anyone interested, I purchased this tool from Performance Tool to suck the fluid from the bottle into the filler hole of the differential. http://www.google.com/products/catal...d=0CGkQ8wIwAg# Save yourself some money and buy online, I paid $15 at Advance Auto Parts.

I also have taken note from reading various threads that I should make sure I can loosen the bolt on the filler hole before I remove the drain plug to ensure I don't end up stuck with an empty differential.

JUAN CASAUS

Sorry about that...I can see how that viscosity could be detrimental to the differential. My car is actually running better with the 75w90 Mobil1 and I did allot of searching and found many people with extensive differential knowledge using this on MB's with no ill effects. In the end I'm just putting in my .02 to save some of us some $ with no drop in quality I guess...

mrobinso

Well... my first attempt at doing a differential fluid flush/replacement failed this weekend. I had all of my tools at the ready, jacked up my car, slid underneath, only to realize that I needed more ground clearance to get anything done! Have any C55 owners changed their own differential fluid? Reaching the filler plug is much more difficult than I anticipated. I have a 18" breaker bar to fit my 14 mm hex socket (which is about 4" long). It was a pretty tight squeeze getting the hex socket into the filler plug, and having done that, I barely had enough space to swing the breaker bar. Instead of wasting time driving to the store to buy better jack stands or ramps on a perfectly nice Sunday afternoon, I decided to postpone this little DIY until I could buy some better jack stands and some thread sealant (for the fill and drain plugs).

Anyone else find that it is a very tight squeeze to remove the filler plug? The exhaust sits directly under the filler plug, rendering a normal socket wrench (90 degree angle) useless. My breaker bar has a hinge fortunately, but I still worry about straining the threads of the filler plug by twisting the plug at an unusual angle.

JUAN CASAUS

I used a 1/2" drive ratchet with a universal joint and a 14mm hex socket. The 4" socket you have is probably too long to get a good shot at it. A breaker bar is overkill it shouldn't be that hard to take off and the slight angle should be absorbed by the universal joint not the threads since it will be straight where it's turning.

mrobinso

Juan, thanks for the input. I went ahead and bought a Torin 2-ton jack and set of Torin jack-stands from www.advanceautoparts.com. FYI, Advance Auto Parts is always having good online rebates. For example, today I bought the jackstands, jack, 4" c-clamp, and 3 packets of brake pad lubricants for $36.00 after using coupon codes. All of that equipment usually would cost $60.84.

To save $25 on orders of $60 or more - coupon code: BIG25
To save $20 on orders of $50 or more - coupon code: A123
You can't combine these, so you have to use one or the other.

Because I have an advance auto parts right down the street I don't have to pay for shipping either as I just pick up my merchandise in-store after work!

Cheers!

JUAN CASAUS

You Should have just bought some ramps and backed your car up on them. Safer and easier...thats what I did and had plenty of room.

lkfoster

With ramps your level within the diff is thrown off. The car needs to be level for the fill to be correct. I don't trust going by recommended quantity of oil, but I know that others do.

mrobinso

I was just planning to use the "fill until you overfill" method, meaning I'll refill the differential through the filler plug until I see the liquid begin to overflow through the filler plug. I read elsewhere that this is an acceptable method. Lkfoster, is this what you are referring to?

lkfoster

That's how I do it, but the car has to be level. If you put the rear end up on ramps you won't be level. I jack the car up at both ends to keep it level.

JUAN CASAUS

I did out on my driveway and the car was almost perfectly level. When you jack it up you're not level either. I filled until overfill as well. Ramps easier and safer.