4.88 seems reasonable. Spicer is a good brand. Whatever you do, don’t let anyone talk you into Yukon gears!!!! https://www.jeepgladiatorforum.com/forum/threads/yukon-gear-fail-at-50k-miles.88590/
A couple things I learned from Death Wobble on my JT that was a little different from the Jeeps I’ve driven and worked on over the last 30 years… YMMV
Of course you shouldn’t just throw parts at the Jeep because some guy on the internet shared his opinion. Try this...
Yukon anything concerns me. Their quality control seems to be terrible. Recommend finding a US, Canada or European manufacturers vs. Chinese.
https://www.jeepgladiatorforum.com/forum/threads/yukon-gear-fail-at-50k-miles.88590/
That’s a way to do it but not the only or easiest way. The negative cable from the aux battery attaches to the negative for the main battery with a common ground. Break that connection on both sides by disconnecting the cables and you break the circuit for the vehicle. I did it here after a regear
The aux battery negative is in with the main battery negative. You undo all the connections on the negative cable side and it’s disconnected. There are things that require a complete disconnect of the battery and a relearn after the code is cleared. YMMV. Good luck.
As much as it pains me to say it, Dealer is your best bet under warranty. You’ll probably need to be skeptical - dealers tend to deal with first cause, not root cause. Could be any number of things and paying someone to diagnose could be a costly job. Good luck and let us know what they find.
I will recommend against getting these.
https://www.quadratec.com/p/quadratec/grab-handles-jeep-wrangler-jl
They are well built but the position they attach makes them too close to the windows and they annoyingly hit the windows all the time. Also the rear ones do not work with the soft top...
I’m having a similar problem. Prob Air in system or faulty slave cylinder. https://www.jeepgladiatorforum.com/forum/threads/manual-transmission-club.17084/post-1439995
If these things don’t work it could be internals and require a tear down to diagnose. Good luck.
Driving my sisters stock 22 JTR through Maryland to work amd getting 14.6mpgs right now. My 20 JTR with 37s and 5.13 gears plus 1,000lbs of stuff was getting about 13.7mpgs before my pinion detonated (YUKON GEARS SUCK!!!!)
Just for perspective - I just bought 2 Rubi axles (M210/M220) with factory lockers and 5.38 Spicer gears for $3500 from a forum member and another $300 shipping. I could install these but I’m paying my shop because its too cold.