Front Differential Oil?

[ferncreekjeep]

'96 LGC, 5.2 V8, Quadtrac
The manual says to use 80/90 gear oil in the front diff. Can I replace with 75/140 synthetic? If so, does it need the additive? On the other hand, the rear calls out 75/140 syn. Does it need an additive?

Thanks

[reekor]

75/140 all around is fine. You only need a friction modifier if your diff has a locker. Unless someone installed one in the front no worries there, the rear may or may not have one factory.

Originally Posted by ferncreekjeep

'96 LGC, 5.2 V8, Quadtrac
The manual says to use 80/90 gear oil in the front diff. Can I replace with 75/140 synthetic? If so, does it need the additive? On the other hand, the rear calls out 75/140 syn. Does it need an additive?

Thanks