Matt's 95 Stang

So I just picked up my new(er) 7.5 with 3.73s and a t-lock this weekend and I was wondering what W gear oil I need for it? Being it comes from a 87 Fox I didnt know if there was any diffence in the weight between the years.

Also, has anyone used Valvoline's gear oil? Any good?

Thanks,
Matthew

hpwrestler220

Just throw in some synthetic gear oil. Any should do fine... Since you now have a t-lok/posi rear, i'm pretty sure you'll need some friction modifier. So a 4oz bottle should be all ya need.

Double check it though. I know thats the case for the 8.8 rear ends. I just went through getting all the stuff myself..

I got 75w140 redline synthetic gear oil and a 3.8 bottle of FORD friction modifier from the dealer...

I THINK that the 7.5's use the 75w90 but please check. Don't go by just me. It should say it in the service manual. If i were you, i would message "cliffyk" on here and ask. He is a very knowledable guy and he will tell you what you should do straight from the manual.

RyansQuick6

I run the recommend Motorcraft 75w140 and one bottle of the Ford Friction Modifier, part #C8AZ-19B546-A. It takes about 2 quarts to fill the rear end.

75w140 is for LSD
80w90 is for Open diff

***edit for misinformation***

hpwrestler220

You sure about that?

Ford had a TSB or something like that with the 8.8's in 2001 and switched the gear oil from 75w90 to 75w140 (at least for the 8.8's...) and we don't have an open diff sooooooo.....

RyansQuick6

That's current as of my 2003 Ford Specifications manual

hpwrestler220

Post #9 & 16...

https://mustangforums.com/forum/4-6l...-how-much.html

You are right about the 7.5 rear. 80w90. He will need friction modifier though.

RyansQuick6

Yeah I looked in my book, I completely switched it up, my bad. I edited the post so nobody gets confused