I read a couple write ups, but want to be 100% sure on what weight gear oil to use for the rear Rubicon axle.

I read to use Royal Purple 75W90 Synthetic Gear Oil.. is this correct..?

How many quarts do I need?

Do I need any special oil for the lockers?

Any help would be great.

 

I run that in mine, i think three quarts? Says in the writeup...

 

Front diff calls for 80w90 2.7 pints, rear calls for 80w90 unless you plan on towing stuff, if you tow you use 75w140 4.75 pints and add 3.4 oz of limited slip additive.

 

No LSD additive for rubicon lockers and or open differentials. + most synthetic gear lubes state they include the addives for LSDs already..

 

Agree^...I used Royal purple -75W90 for my Diff's and I didn't need additives for the LSD using Royal Purple in my Sahara.

 

According to the write up the front takes 1.35 quart and the rear takes 2.375 quarts. I just changed mine again this past weekend. I also use Royal Purple. You don't want to over fill the diffs. It will run out the breather tubes and smell to high heaven for a couple of weeks. Found out the hard way the first time I changed them. No problems this time though.

 

Awesome! Thanks everyone for the info.

 

Mine spewed from the breather in the front axle with the 100% factory fill level in it. Had probably 300 miles on the rig and went for a 3 hour drive

 

So 4 qts total.
Does it matter if I'm running aftermarket diff covers, like the Teraflex covers?
I'd like to change my fluid this weekend too!

 

Don't quote me on this but I think with some aftermarket covers like ARB for instance, you need to add more gear oil.