rharr
Well-Known Member
- Joined
- May 6, 2021
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- 20
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- 1,265
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- Location
- Tucson, AZ
- Vehicle(s)
- 21 JTRD 3" RKK lift, (former) 95 XJ 5sp 8" lift
- Thread starter
- #1
Just a FYI for anyone that cares, was at my buddies shop helping with a regear on another friends JTR, we popped the drain and rear dif cover and what a nasty gross stinky dark mess. The oil in rear diff was coffee brown, burnt smelling, with a fair amount of metal fines on the magnets. Buddy said it looked like 80k mile oil.
This JT is just a daily driver, no towing, no abuse, so for the oil to be toast at 8k is very surprising. The good news is Jeep makes it very easy to change the oil in the diff, don't even need to pop the cover, so anyone that cares, it might be worth a hour of your time to dump the factory stuff if you haven't done it yet. That's my weekend project....
Also of note was the amount of metal filing that collected on the locker phase sensor (aka the little switch on the carrier that tells the ECU the locker is locked or unlocked) this phase switch uses a small magnet to identify its position, and if it is caked in metal it's going to screw up the signal, I suspect that is what is happing to all the folks that are having locker/4x4 error codes. It's easy enough to clean if the carrier is out of the axel and the bearing is pulled but more tricky if everything stays assembled.
To keep the filings down, a fluid replacement in the first 3k or less would seem prudent to catch all the stuff stirred up from a break in on a new jeep and maybe going full synthetic (75w-85 (GL-5) 1.5 liters). I am also thinking about getting a second magnetic drain plug and replacing my oil fill plug with it, to further help catch any metal.
This JT is just a daily driver, no towing, no abuse, so for the oil to be toast at 8k is very surprising. The good news is Jeep makes it very easy to change the oil in the diff, don't even need to pop the cover, so anyone that cares, it might be worth a hour of your time to dump the factory stuff if you haven't done it yet. That's my weekend project....
Also of note was the amount of metal filing that collected on the locker phase sensor (aka the little switch on the carrier that tells the ECU the locker is locked or unlocked) this phase switch uses a small magnet to identify its position, and if it is caked in metal it's going to screw up the signal, I suspect that is what is happing to all the folks that are having locker/4x4 error codes. It's easy enough to clean if the carrier is out of the axel and the bearing is pulled but more tricky if everything stays assembled.
To keep the filings down, a fluid replacement in the first 3k or less would seem prudent to catch all the stuff stirred up from a break in on a new jeep and maybe going full synthetic (75w-85 (GL-5) 1.5 liters). I am also thinking about getting a second magnetic drain plug and replacing my oil fill plug with it, to further help catch any metal.
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