What's the best lube for G2 gears? Rear is limited slip.
 

2011 JKU Dana 44 limited slip rear, Dana 30 front, 4.56 G2 gears

There's really no "best" per se. You just need to make sure either what you use has an additive in it, which most synthetics these days will, or to use an additive for the LSD.

Ok, thanks. Reason I was asking is because my rear axle seals and both pinion seals blew out within two years of the gear swap. The shop that did the job replaced the seals under warranty, but offered no clue as to what might have caused the seals to fail. I just want to make sure I’m using the correct oil. I’ve had a really bad experience with this shop, and I have no faith in what they tell me. The front pinion is leaking again after only about three weeks.

I recall that some diff lockers specifically recommend against synthetic fluid. Maybe someone on here can add the details I am missing.

https://cimg1.ibsrv.net/gimg/www.jk-...983661e85.jpeg
Found small pieces of spring in the rear diff
https://cimg3.ibsrv.net/gimg/www.jk-...8d9e9d2ca.jpeg
Any idea if I need to be concerned with this?
Following. Just changed my Dana 30 & 44 gear oil. I used Lucas 75w-90 Synthetic, 2.365 quarts in rear & I had a Qt of 80w-90 (non-synthetic) that I put in the front. I have 4.88 gears and an Eaton locker for the rear.

That looks like the spring that is in the pinion seal. I can't think of any other place a spring like that is in the rear. Given your jeep is an '08, have to think that pinion seal has been changed a couple times in the past. No clue, if that is what it is, how it could have gotten down in there. It's obviously not good at all, but given how flimsy it is compared to ring, pinion, and spyder gears, I'd think you're generally ok.

I had my gears changed 2 years ago by 4 Wheel Parts, I upgraded my driveshafts a year later and when I went to put the rear shaft flange on the pinion nut was all rounded out so I took it back to 4 Wheel Parts because they were the ones that screwed it up and they ended up finishing my rear driveshaft upgrade install. I haven’t touched it since and haven’t had any problems with leakage but I think you are right that that is one of the springs in a seal. Wondering if when they pulled the pinion nut off that they pulled the seal and some of the debris got in there. Haven’t had any problems wheeling it so hoping that this is some debris from them.

are your vents plugged?