RAudi Driver

I'm prepping to change out the fluid on both diffs. I have PTV+ and know that I'll need a LS rated fluid for the rear.

I'm going to go with Motul as it's the oil I use in everything with a motor here at the house. Motul makes a Gear 300 75W-90 for the diff. They also make a Gear 300 75w-90 LS for Limited slip diffs. Since the front only requires like 1/2 liter and the rear appears to require 1.3 liters, I'm wondering if I can put LS in the front also? If not then I'll just pick up 2 bottles of LS for the rear and one non LS for the front. Hate to waste when I don't have to though.

Any input is greatly appreciated.


Oh, also going to change out the transmission fluid while I'm under the car. Yes, Motul again.

Slickdvl

Uh oh ... not to sidetrack too much, how do you know you have PTV? I recently used non LSD in y rear diff ‘12 CTT

RAudi Driver

It stated on the Monroney.

Slickdvl

What?

Spyerx

Ls fluid has an added fluid to make a diff less noisy and generally less effective. It keeps the plates from chattering.
On all my lsd equipped sports cars i use non ls motul even tho the car has lsd. On my 89 i did use motul ls fluid.

I suspect you’ll be fine either way.

RAudi Driver

Interesting, thanks Spyrex

twodollardoug

I used the same gear oil front and rear (not motul).

RAudi Driver

Anyone have a picture of the drain plug washer. I want to do this today but didn't get the washer yet. I have washers from a slew of other German cars in the garage and wondering if one of them is the same?

RAudi Driver

Found it. I don't have one of these.

https://sierramadrecollection.com/Se...14-p30773.html



Found it. I don't have one of these.

https://sierramadrecollection.com/Se...14-p30773.html

Slickdvl

Washer, for what? All my plugs were simply that with some rubber sealer around the threads

RAudi Driver

Really, how would you feel reusing the same plug? I will order a few tonight but would like to do the job and just put the same plugs back in and call it a day. I've got an extremely busy work schedule that just got thrown on me and I'm racing to get a bunch of stuff done and make something of this Memorial Day.

Slickdvl

I guess you could reuse once, but, also you could try getting some sealant and apply it.

RAudi Driver

Cool, I'll let you know how it goes. Raining today so it's a garage day.

gekko997

I do not have the PTV, but when I changed my front and rear diff I just reused the rubber washers. I did order some just in case, but accidentally ordered the washers for the transmission. In my case, the rubber part was in good condition - just cleaned and reinstalled. No issues thus far.

I did use same gear oil for both - amsoil severe gear 75w-90.

twodollardoug

I have ptv and I used the same oil front and rear.