Just need to know if my 1996 Blazer 4x4 requires rear end addiative? There is no tag on it and I assume noting needs to be done. I do know that the rear end is 8 1/2. Hope someone has some input on this. Thanks!

No additives required.
Always a good idea to change it if high mileage.
Rear ends do collect moisture over time.
Locking and non-locking calls for 80-90 WT - API GL5 gear lube.

For serere service or heavy towing you can use 75-140 Synthetic
But if you cange it over from reg to symthetic it will need flushed out before change over.
MT