Need a reminder on front driveshaft

[JTPatriot]

I can not remember. Does the front drive shaft freely turn if parked in 2 hi. I thought it did, but I was checking things over after the oil change and my front driveshaft will not turn. Pulled the fad to make sure the collar was in the ring, which it was and it was in the disconnect state. Rocked the jeep back and forth in park, rear driveshaft moves as it should but the front did not. Something going on in the transfer case? This is on a 2020 Gladiator Rubicon.

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[Free2roam]

Well if it's "parked" nothing turns

 

[whysoserious]

I can not remember. Does the front drive shaft freely turn if parked in 2 hi. I thought it did, but I was checking things over after the oil change and my front driveshaft will not turn. Pulled the fad to make sure the collar was in the ring, which it was and it was in the disconnect state. Rocked the jeep back and forth in park, rear driveshaft moves as it should but the front did not. Something going on in the transfer case? This is on a 2020 Gladiator Rubicon.

On a 2021 Jeep Gladiator Mojave, when parked in my garage, in 2wd High, and in park, without the engine running, the garage door closed, at 1925 hours Central time, in Texas, the front driveshaft turns freely.

So, the only conclusion I can come to is one of ours is not working right.

 

[Gvsukids]

So, the only conclusion I can come to is one of ours is not working right.

Better contact Jeepcares.

 

[whysoserious]

Better contact Jeepcares.

Sounds expensive.

 

[Fultor]

If the front and back wheels are touching the ground with the vehicle at zero speed, both axles should not turn. There is though a little rotational play because of backlash in the diferentials.

 

[DylanM]

With the transfer case in 2HI the front diff should be unlocked and the FAD disconnected, so the net effect is the same as having the right front wheel not touching the ground. The front driveshaft should be able to be spun in this situation as it isn't coupled to the rear driveline, nor to both front wheels.

 

[Jteakus]

Front driveshaft should free spin in 2-High with transmission in park.

 

[JeepOfTheseus]

With the transfer case in 2HI the front diff should be unlocked and the FAD disconnected, so the net effect is the same as having the right front wheel not touching the ground. The front driveshaft should be able to be spun in this situation as it isn't coupled to the rear driveline, nor to both front wheels.

It's basically recreating the scenario that open differentials "fail" in. In this case, the driver's side has 100% resistance while the passenger has 0%. This allows the two planet gears to rotate about the fixed driver's sun gear, but something has to give: the passenger sun gear rotates, i.e. the passenger inner shaft rotates (which is possible with the wheels on the ground since the FAD is disconnected).

If the front and back wheels are touching the ground with the vehicle at zero speed, both axles should not turn. There is though a little rotational play because of backlash in the diferentials.

Only if the transfer case was engaged with the front driveshaft (it's not) or if the FAD is connected or removed/doesn't exist (pretty sure 2020 Rubicons came with FAD).

 

[Bully4]

Just looked at my 25 Rubicon. Appears to have a block off plate where FAD mounts. Research online says that some newer vehicles don't have FAD. Mine won't turn unless you jack up a front wheel.

 

[JTPatriot]

I Just got back from driving around and I shifted the transfer case into both 4 hi and 4 lo. Locked and unlocked the differentials. Checked the front driveshaft when I got home, still unable to rotate the front driveshaft. I had my Yukon ring and pinions replaced with Dana Spicer gears a few weeks back. May have to hit the installer up and see if he has any ideas. Everything seems to work, may need to put a camera under the Jeep and see if it is turning while driving in 2 hi. Thanks for everyone's replies with actual responses.

 

[Jteakus]

Did you by chance do a front axle upgrade with a FAD delete?

 

[Stan H]

I Just got back from driving around and I shifted the transfer case into both 4 hi and 4 lo. Locked and unlocked the differentials. Checked the front driveshaft when I got home, still unable to rotate the front driveshaft. I had my Yukon ring and pinions replaced with Dana Spicer gears a few weeks back. May have to hit the installer up and see if he has any ideas. Everything seems to work, may need to put a camera under the Jeep and see if it is turning while driving in 2 hi. Thanks for everyone's replies with actual responses.

Try this if ya want... Have someone you trust ie... wife.. uh okay someone you trust start truck meanwhile you get behind the front passenger wheel listen to the FAD when you have then pull it into 4wd. you should here it run

 

[Stan H]

On a 2021 Jeep Gladiator Mojave, when parked in my garage, in 2wd High, and in park, without the engine running, the garage door closed, at 1925 hours Central time, in Texas, the front driveshaft turns freely.

So, the only conclusion I can come to is one of ours is not working right.

This is the way

 

[Stan H]

On a 2021 Jeep Gladiator Mojave, when parked in my garage, in 2wd High, and in park, without the engine running, the garage door closed, at 1925 hours Central time, in Texas, the front driveshaft turns freely.

So, the only conclusion I can come to is one of ours is not working right.

This is the way

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