Well I just ordered my gears from Wayne at diffsonly. Great guy! Anyway Im going to take it to the shop next week to have them installed. Im currently on 8in lift and 37s and got some 4.88s Yukons/master install kits. WHAT gear oil do I need to run? AND whats all this talk about friction modifiers and where do I get a bottle?

 

You will need 80w-90 oil for the front differential and 75w-140 oil for the rear differential. Friction modifier i got from my dealer for like 6 bucks. For my truck i used quaker state oil full synthetic since switching gears without issues. You are gonna love ur truck even more after regearing i know i do.

 

oh and one more thing you might as well buy double the amount of oil/friction modifier because you will have to change ur oil after a couple hundred miles.

 

Im going to be towing a 28ft pop up/toy hauler. With everything loaded up should be around 6400lbs. HAD to get the gears since being on the 37s...

 

good call on the double oil!

 

Most gear manufacturers recommend the break in with a non-synthetic oil.

 

Kewl!
Your tranny is going to thank you.....