i have a 2001 gmc yukon slt and i dont know if i should use limited slip additive to the rear diff along with the 75w90 syn oil
Contrary to what you have been told,synthectic rear diff lube is all these positracts need,they are not fully loaded units and don,t require the additive like the corvettes and camaros do.
NO do not use additive for that year model. 75w90 synthetic is all that you need.
diff oil additives usually are for problem diffs unless stated in service requirements. diff additive is added to free up the diff if when turning corners the inner wheel skips so to speak meaning the inner wheel is turning at the same ratio as the outer wheel.
