My 06 D/A is ready for its first rear diff fluid change. I run AMSOIL syn oil, so I will use the severe gear 75w90 syn diff fluid. Will I need to use rvt silicone, buy a new gasget or can I reuse the exhisting gasget if there is one ? Thanks for any help.

:grd: I went with the GM "grape juice". Using heavier weight (75 X 140) I tow a a 10,000 lb fifth wheel (GM has advised those that tow heavy and often that they may install 75W-140 full synthetic oil to help combat heat and friction. Helps ensure long life and proper operation under extreme use). Use permatex RTV blue or red.



2005 Chevy Silverado CC LB 3500 SRW - LLY Duramax, Bed Rug bed liner, Bilstein shocks, Isspro gauges, Luverrne SS running boards, Allison deep pan, PML diff. cover, Silverline 4" CAT back exhaust, Dunlop Rover RVXT LT265/75R16, Handy fifth wheel tail gate

you don't need to pull the cover off the diff to change the fluid, it has a square drain plug in the bottom--a 3/8" ratchet extension fits perfect. Your fill plug does have a gasket but if you're careful when you take it out you can reuse it..easiest differential fluid change I ever did!!

Thanks for the help. Sounds like an easy change