RainsFather

i have had quite a bit going on lately and noticed that i was 100 miles over my oil change and decided to take it to an oil change shop. the dealer did the last change and it took almost 2hours because they are so busy ( total b.s. ) and i just moved so my garage is just not the place to do anything right now. i told them not to do their 45 point inspection as the car only has 9k miles on it and honestly i just didnt need them to waste their time. well, when it was done the guy told me that the oil in the rearend needed changed and of coarse i looked at him like he was retarded. then he showed me what it looked like, it was kinda grey and not what i expected. i did not have them change it though as i thought it might be some kind of synthetic oil and that it was normal. Is this normal or should i take it to the dealer and have them figure it out?

Argonaut

I replaced mine at about 9K and it was that color. Its not a bad idea to replace the oil after the gears break in but its really not required (there was a recent thread on this subject and opinions were all over the place). If you are worried, take it to the dealer. If water or contaminent has gotten in there it might be a bigger problem but chances are the dealer is going to tell you its normal.

JimsGT

First off, is this an oil change place? I would never let them do anything on my car. ( I went to Jiffy Lube with my DD Honda and I needed to use a breaker bar to lossen my oil drain plug!) But anyway, at best, yes, good you waived the 45 pt inspection, unless it was the dealer, its a normal thing every time you go in there.

At 9k miles, even if you had gears done, changing gear oil in the rear should not be on anyone's mind, especially those guys! Was there any noise coming from the rear? If not, leave it alone. In addition to the stock oil fill, there is a Ford friction modifier additive that is in the oil. As far as the color, I'm not sure, but in my line of work, grey in the oil means the Babbit surface of the bearings is coming off, not good, BUT I don't know the color of the additive or the stock gear oil. If the color's ok by someone else, then leave it alone. Gear oil is not be changed for a long time ( don't know the exact mileage but I think its in the owner's manual under maintenance)

99BlackPonyGT

well im not sure about your car...but my car had a full fluid tune up...me and my buddy did oil tranny and gear oil... about 500 miles later i took it to the track and i shredded my spider gears on my first pass, so i pulled the diff cover to fix it and my gear oil was grey after 500miles...not sure if thats normal or caused by my **** breaking in the rear end or what, but at 9k miles i wouldnt worry about it...its not reccomended until 60 if i remember right

http://www.moddedmustangs.com/forums...intenance.html

theres a link to a maintenance suggestion chart

60k miles

moosestang

It's normal! I'm fairly sure the gray is from the ford friction modifier.

99BlackPonyGT

my old rp turned grey... it went in purple with its own friction modifier and came out purple/grey...

Simon1

Gear oil is nasty looking and smells even worse.

I just changed mine but I have a drain on my diff. so it was easy.

moosestang

You're right, I just checked a used bottle of FM and it's a greenish color. The gray color maybe from the disks in the clutch packs. It won't hurt to change it at 10,000 miles, but it's not necessary.

Anyway, mine was gray when I had my gears done at only 6,000 miles.

moosestang

The smell is from the friction modifier. If you buy a gear oil that doesn't contain any, it won't smell like rotten eggs. Your rear end will sound like a rock polisher though.

MexGT

+1 being a very stinky oil.