Thanks to everybody for the info, I think I'll take Jerry's advice and roll with a good conventional. I have never changed my front and rear differentials before so any tips or advice would be cool.
Is Lube Locker any good?
- Thread starter JRUBIC0N
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crackedcornish
TJ Enthusiast
I’d run it. Once it compresses between the diff cover and the diff face it should straighten out and seal.
The shop that did my gear install said to use Lucas 85W-140 heavy duty gear oil. He said since you're supposed to change the fluid at 500 miles and some people never do, that's what works the best for those that forget.
Keep in mind that this is a five year old thread I hijacked to ask about my gasket.
That gear oil is also conventional which is what you want with new gears, during break in at a minimum if not forever. That's what I have ready to do a gear oil change in my stock Rubicon gears. I'm just waiting on warmer weather at this point.
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Vtx531
TJ Addict
Might not work for those in colder climates - I think 85w-140 is too thick at very cold temperatures but probably good advice for Houston
Realized that after I posted... My guy does only axles/differentials/gears. He said he gave free fluid changes to people to see how the gears did while trying several different oils, and the lucas was the best, and had the least amount of issues, even when people never changed fluid after break in.
Its still 85W equivalent in cold weather, and in the range for typical gear oils, its not like running straight 140w.
Rubicon specs 75W-140 in all climates. I highly doubt 85W-140 would be thicker enough to cause issues. I would run the spec but I can't find non synthetic 75W-140 anywhere.
I have a Rubicon and I don't see a drain plug on either end. I'm not the original owner though so someone might have changed the covers in the 15 years I didn't own it.
Its on the side of the main differential housing on the right side. Not the cover. The cover has a fill plug.
I run Castrol 84W140 synthetic without friction modifier in my rear diff in Colorado. It's fine. It's the 140 you care about once warmed up. The Rubicon Dana 44 front can run a lighter 75W90, but it's equally difficult to find that grade without friction modifier and I just run the valvoline stuff in a bag.
I keep one of those bags on hand and refill it for the rear diff. I've never had an oil pump last long with the diff oil for some reason.
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I guess I've only ever seen pictures of aftermarket covers with drain plugs on them.
I was just planning to use the same Lucas 85W-140 I'm using in the rear. One gallon jug should be able to do both ends with a little leftover.
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