View Full Version : Coastal 75-90 good for differential fluid? [pic]

01-16-2008, 09:20 AM
just wanted to make sure this is ok to use for flushing my differential fluid. I'm in a 2001 A4 30v quattro auto/tip. i understand there are 3 different spots to change the differential fluid:

- before tranny
- after tranny
- rear differential

i was told by a local audi mechanic to get 75/90 and make sure it's Gl-5, which this appears to be. got 6 quarts from advanced auto parts. am i ok to use this?


01-16-2008, 10:46 AM
yeah any GL-5 approved fluid is good, I just did my rear diff with mobil 1 synthetic 75w-90

01-16-2008, 02:50 PM
my post on AW is getting back that this oil is shit. i'm going to return it for mobil 1, which others have said they used without problems. this brand, at least 1 person said it went to shit 15k miles later.

01-16-2008, 03:09 PM
I would skip on the coastal. it's pretty much bargain basement fluid.

75w90 gl4/5 rated gear oil is what you need.

redline 75w90
mobil 1 75w90

are both oils I've run in the rear diff.

01-16-2008, 04:24 PM
Honestly, I would go with OEM to be safe... I got royal poophole and now I am grinding almost every gear 10k miles later... And there are only two places to fill up...

01-16-2008, 05:29 PM
i would go with a better brand if i were you

01-16-2008, 10:01 PM
they say never judge a book by it's cover, but in the case i think that applies for this stuff.

09-04-2008, 05:19 AM
I have used this fluid on Nissans on the past and have it currently in my 99.5 2.8 5 speed (tranny and diff), but I have a hard time shifting into all gears once the fluid warms up and I have audible gear whine that is RPM and gear independent. I will be replacing with a better fluid.