help: diff fluid change

[blazerpro79]

hey guys im going to paint my diff cover, and need help changing my differential fluid. i have a few questions...

how do i know when it is full? and what grade you guys suggest for new gear oil? thanks a lot.

 

[85mudblazin]

your going to paint your diff cover??
well if you just want to change the fluid for the hell of it just fill it up till it comes out of the fill hole.
I use 80/90

 

[blazerpro79]

ya i want to take it off to paint it... my truck is more of a street cruiser. ill post pics tomorrow

 

[Hossbaby50]

Just fill the diff till it comes out the fill hole. Should be 3-4 quarts normally. If it gets hot where you are in California then I would run 85W-140 gear oil. It will take the heat better then 80W-90 will.

Harley

 

[blazerpro79]

do i need limited slip diff fluid or anything special? im doing the front and back.

 

[Big Red]

if u have a L/S, then yes, u'll need to add an additive to it. Advance sells it for like $5. I used it all the time till my tranny blew. lol.

 

[blazerpro79]

i know if i have limited slip if:
i jack it up and one wheel spins with the other? or is that posi?

 

[Hossbaby50]

The front won't have a posi unless it is aftermarket so you don't need the additive for that. If the rear has the govlock you should probably add the modifier into the diff. I was always told to use the GM additive from the dealer. I think it was like $8 or something like that.

Harley