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Whats A Good Diff Fluid?

4K views 24 replies 12 participants last post by  Chiefmorton 
#1 ·
Been thinking about changing my front and rear diff fluid what do you guys recommend?
 
#6 ·
i changed to royal purple when i did my 4.56 gears and DAYMMM it was expensive
 
#7 ·
do you need the limited slip additive with the synthetic gear oil??
 
#12 ·
so you dont need the additive with amsoil or RP?
 
#13 · (Edited)
I won't ever run Royal Purple in the crankcase or tranny. their oil analysis's are always the absolute worst. their diff oil may be okay but their name is tainted in my book forever. head over to bobistheoilguy.com and do some reading, they have a axle oil section i believe.

Mike L once said he wouldn't flush his toilet with Dex VI, that's how a bunch of people feel about RP. If you're gonna pay for an expensive synthetic go Amsoil, M1, Redline, w/e
 
#17 ·
Brian why BG and not amsoil? so you run an limited slip additive with the synthetic eh?
 
#18 ·
But in the auto transfer case I put the autotrac from gm.
You used the wrong fluid. Drain it.

Brian why BG and not amsoil? so you run an limited slip additive with the synthetic eh?

Because I stock 30 gallons if it at my work and I get it very cheap. I don't drink the cool-aid regarding amsoil either, I know where the good shit is Heyyaa

And yes, I run a addative with my synthetic diff fluid.



 
#16 ·
I strongly recommend gear oil.
 
#23 ·
I'm leaning towards Lucas 75/90 which is synthetic, is there any issues in running the synthetic stuff in a 2001? I thought I read somehwere about changing a vent tube or something if switching to synthetic.
 
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