I just swaped in my new rear diff in today and i drained the old fluid and filled it with royal purple 75w90. its an oem diff. will that work for me? Ive read if people using 110, 140, and 90. Will i be good with 75w90? and is that royal p stuff any good? i dont want to blow up my rear diff again...

 

Wait you blew a diff. So you put a fluid you aren't sure of into your car on your second diff. Wouldn't you want to be sure what you are putting in before you put it in

With that said royal purple isn't that high of quality stuff. I would put Mobil 1 before rp, and def amsoil before Mobil 1.

 

Well I read about a few people running rp and loving it but the posts were old and I though maybe something changed and wanted to get a better accurate up to date answer. And I'm not so much worried about the brand but more towards the viscocity. Will I be okay with 75w90? I live in Texas where it can get pretty hot.. and on my next fluid change I can do amsoil but should I be good for tge next 10k miles or am I in danger of blowing up my diff?

 

Amsoil Severe Gear 75w-110.

/endthread

 

Whats the difference between 75w-90 and 75w-110. Im replacing my diff fluid soon too and people recomend both types.
Meant to type 110, sorry lol.

 

^huh?

 

I've been using RP 75w-90 for the last 3 years without a problem. Will be switching to Amsoil on the next change though.

 

^this

 

amsoil 75w-110.

 

Don't use 75w-90. It isn't good. You should use 75w-90 instead. That's really good.