Need a reminder on front driveshaft

[mjfrank]

If it drives okay still, it sounds like they screwed something up with your front locker and it’s permanently locked. If the FAD is still disconnecting, you won’t notice anything different in 2hi, but your drivers and passenger side axle before the FAD will be turning along with the front drive shaft. Should be able to jack up the drivers front tire and see if it turns along with the driveshaft to confirm.
Mike

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[Stan H]

If it drives okay still, it sounds like they screwed something up with your front locker and it’s permanently locked. If the FAD is still disconnecting, you won’t notice anything different in 2hi, but your drivers and passenger side axle before the FAD will be turning along with the front drive shaft. Should be able to jack up the drivers front tire and see if it turns along with the driveshaft to confirm.
Mike

It is rare but the FAD unit motor could have possibly failed or or the connection is corroded and needs cleaned then dialelectric grease put back and plugged in.

 

[mjfrank]

It is rare but the FAD unit motor could have possibly failed or or the connection is corroded and needs cleaned then dialelectric grease put back and plugged in.

It certainly could be, but he mentioned he already pulled the FAD motor, made sure it was engaged in the collar and the collar was disconnected, so the next possibility is that the locker is locked, stuck, or his gear change guy swapped it for a spool. Not sure if any of that would cause a warning light or not, but lifting one tire at a time and spinning it will help rule things out. If the driveshaft is spinning with the left tire, and the right is still on the ground, and you’re 100% sure the FAD is unlocked, then there may be an issue with the locker. If you can’t turn the left tire at all, both the locker and the FAD are locked. Switch to only the right tire in the air and if spinning it spins the driveshaft, the FAD is locked and the locker is unlocked. If the tire spins with nothing else in the front end turning, the FAD is unlocked and the locker or carrier is likely the issue. Definitely getting whomever changed the gears involved is the right direction.
Mike

 

[Zachanadandy]

I agree with others, something is sticking. Could be the transfer case is sticking in 4hi, could be the locker, could be the fad. Jack up the drivers tire and spin it. If it won't spin at all then you have multiple things stuck as it would have to be locked with either the FAD stuck or the tcase in 4hi. If it spins and the driveshaft doesn't then the FAD and tcase are fine but the locker is engaged. Good luck.

 

[slodsm]

The driveshaft should turn freely unless you’ve done a FAD delete or have an auto locker.

 

[JTPatriot]

Update time!
I just got done lifting each front tire, leaving opposite tire on the ground. Both sides spin independently. Shifted transfer case into neutral, shaft would spin with both front tires on the ground, as expected. Shifted transfer case back into 2 hi with both front tires on the ground, driveshaft spins freely!
So, I have no idea but it is working as it should, so all is good.

Thanks again for everyone's comments.

 

[Jteakus]

Sliding collar must have been hung a little.
If I were you, I would engage 4X4 several times before you actually need it to verify all is well.
Congrats on your "repair"!

 

[arosen1997]

It is rare but the FAD unit motor could have possibly failed or or the connection is corroded and needs cleaned then dialelectric grease put back and plugged in.

FAD get lubricated by the gear oil from the diff, I wouldn't put a grease in there, grease mixing with oils can have some strange results.

 

[Stan H]

Jus

FAD get lubricated by the gear oil from the diff, I wouldn't put a grease in there, grease mixing with oils can have some strange results.

The wiring harness plug is all I am referencing

 

[Dilly’S Willy]

Sliding collar must have been hung a little.
If I were you, I would engage 4X4 several times before you actually need it to verify all is well.
Congrats on your "repair"!

I met a guy with a JK Rubicon a few month ago, said he loved the Wrangler but had a CEL on and his lockers didn't work with 80k miles on them. Asked if the ever used or even engaged the lockers since he bought it, "Nope" was the reply. Asked if he ever used the 4x4 system, "Nope, well maybe sometimes in the winter." Asked when the last time he changed his diff/t-case fluids, "wait you need to do that?"... some people either shouldn't be allowed to owned things, or they need to start learning how to ask for help with they don't know/understand something. Dunning-Kruger Effect or something like that.

Sometimes you need to use functions even if you don't need them in the moment. A simple cycling of the function ON/OFF and verifying it's working can (and usually does) prevent premature/general failure from lack of use.

I engage my 4LO once a month regardless if I NEED it at the moment. Keeps things lubed, moving, and verifies they still work. I turn ON the ESS system every other week to test the AUX battery (was acting up months ago). I take off aggressively from a start every few weeks to verify my LSD is still locking (Anti-Spin LSD, aka clutch-based LSD).
- Sometimes I drive in bad rain storms to verify my door seals are still pissing like a drunken sailor. Oh wait, they shouldn't be leaking that bad...

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