I bought it with 30k and I was already planning on doing it soon, the front seal leaking just saved me from having to do the front one lol. Now I just have to do the rear one when I do the brakes this weekend

 

It's a super easy job. Just make sure you have a transfer pump.

 

Dino 75-90W like Dirtman stated. Don't need synthetic. Hand pump from hardware store works. Only takes just a shade less than 2.5qts (for D44) and bit less for D30.
Probably showing my age but - decades ago back in New Zealand, where I grew up, had a car that lost the oil from the diff because the drain came out. We were way out at a resort and we managed to get a pipe plug to replace it. No oil though so (this is hard to believe) we used banana peels for diff lube for the 20 miles back to town but we drove slow. Left the skins in and topped up with oil. Never an issue.

 

Any GL-5 is perfect and will serve it's purpose just fine as already mentioned. I use Valvoline synthetic 75w-140 front and rear. Buy what brand you trust and stick with it.

 

After my recent purchase I had both diffs serviced. He actually popped the covers off, cleaned & inspected the gear sets and filled them with Royal Purple.

 

Good grief. Was that just an idea that sprang to mind when looking around at your resources or are banana peels a cure-all, fix-all remedy down under? Great story.

 

What did that cost?

 

Probably way too much lol

 

Believe it or not, $100 for both, he's a JKU enthusiast, super detailed. He was just going to undercoat the exposed frame areas of mine after the lift and ended up doing the whole thing. He said, "he couldn't help it" & didn't charge me any extra. He did the same when he replaced the upper oil pan gasket, flushed & filled the tranny, he just drained & refilled the t-case though. Everything was cleaned prior to buttoning everything back up. He even took "before" & "after" pics as we went through the process

 

No it was true. Dad told me about it years before so people had bananas around we got the peels. Car ran fine for another year then got rid of it. Of course my JK gets fixed properly nowadays.