Join Date: Jan 2006
Location: Northern California
Thanked 2,606 Times in 2,101 Posts
I run RP only because it was readily available to me at the time and it was full synthetic and came in the viscosity I was after. Been running it for years and I often check the diff cover magnet for debris, and there's none.
That said, someone I know ran Valvoline full synthetic and they never could stop the limited slip from chattering. Was so annoying they swapped it out for conventional fluid and problem went away.
I dont think I've ever read or heard of anyone having differential problems because of the fluid brand they used. Lack of maintenance, abuse, and contamination are generally the cause of such things. So I agree...run whatever brand you want as long as it meets the specs for your application.
'01 2500 Sport 4x4 5spd w/Fastcoolers, Mag-Hytec, EZ, RV275's, 4" w/o muffler, South Bend, Steering brace, aFe, 2 lo kit, Isspro Boost, FP, and EGT on pillar, Westach Trans/Diff temp gauge in dash pod, Raptor 100 w/ 1/2" line, Pac Brake, Rancho 9000, 285's