i need to replace my rear diff fluid. i want to go with the royalpurple stuff. summit has 3 kinds not sure what weight to use. 75W90,75W140, 85W140.

what do you guys use?

 

never mind i found an older post that said what to use. royal purple says not use use an additive? should i follow their recommendation.

edit: nvm again. found that too.

 

haha what rear do you have they may be different

 

3.55 but i think u are asking if its the 8.25 or 9 something. to that i dont know but in the older post one took 2.2q and the other 2.4

 

so i attempted to change the diff fluid today. and i made the mistake of buying a POS, good for nothing, Chinese made, worthless, useless, rip off siphon to get the fluid out. after about 1hr of siphoning i figured i had most of the fluid out, turns out i only got a little over 1qt out. and filled it with the new stuff. if walmart dosent have a better one then i will leave the 50/50 mix. good idea? who knows. but sure is fun to break them tires loose.

 

you guys think i can leave my 50/50 mix or pull all the crap out and do it again. i got a better pump now aka syringe.

 

y didn't u just remove the diff cover? thats what i would prolly do.
did u actually notice a difference in driving quality? if so i might think about doin this, doubt it has ever been done on my truck

 

well i first thought that taking the cover off would be to messy. i was wrong, it would have been a lot easier. i shoulda just done that. i was never able to break my tires loose unelss it was wet. now i hit the gas at like 10mph and they squeal like pure sin.

 

yea i dont think it uses a gasket i think it is some black caulk looking stuff that seals it.
ive got the 9.25 rear end thats prolly what urs is.
is ur diff cover oval shape or is it kinda diamond shaped. if oval its the 8 if diamond its the 9

 

rtv sealant. and yea its the 9.