It is time to change the fluid in the front and rear diffs. I know alot of guys swear by Amsoil but I was wondering how the Redline fluids compared? Also what are the capacities of both diffs?

Thanks

 

I was also wondering if anyone knows if you need to add a friction modifier to the Redline or does it have something mixed in it already?

Thanks

 

I believe the stock Dana 70 holds 7 3/4 pints. The Dana 60 holds about the same. The Dana 80 holds a tad over 10 pints. With Redline, you will need to add modifier. I've found the Chrysler stuff works best, but Kendall works good too. I've tried "Trans-X", but I didn't care for it.

 

I"m running Redline 75-140, but I don't have L/S. ;-( Redline does have their own friction modifier, some need it...some don't. I'd go with that or chryslers. The one constant I see about these L/S's is they're all different in their regards to friction modifier needs.

 

Check out the Royal Purple, been using it for years. Excellent results in boats, trucks, cars, jeeps. It's availible from Jegs.

 

i'm using redline mtl in my trans.( nv5600). valvoline dura blend 80/90 in my diffs,and mobil 1 atf in my transfer case.unless you are putting alot of miles on your truck in 4x4 you don't really need to change your front diff oil as often.i changed mine at 50,000miles it looked like new.i will change my front diff. every other time i change the rear. if i used full synthetic in my diffs. i'd use redline

 

Joe Donnely over on the TDR did a rear end lube dyno test 3 years ago. LE won with a 7 hp advantage.

 

Whatever fluid you use, after changeout, it's recommended to find a parking lot and drive the truck in several tight figure of 8 patterns to get the new fluid worked in. If you have limited slip, and experience chatter after this procedure, then I'd get some external friction modifier, and only add a little at a time, until the chatter disappears.

Good luck, and Redline is great stuff.