Your Wrangler doesn't have full-time. No Wranglers ever had a full-time 4x4 ability, all are strictly part-time. Your instrument panel only includes a full-time indicator light because it was shared with the Cherokee which did have a full-time 4x4 system available at extra cost.

 

Full Time: The vehicle is always in 4x4, sort of like an all wheel drive system on a Subaru

Part Time: The vehicle is only in 4x4 when you put it in 4x4

Hope this helps.

 

Full Time: The vehicle is always in 4x4, sort of like an all wheel drive system on a Subaru

Part Time: The vehicle is only in 4x4 when you put it in 4x4

Incorrect. Having a part-time 4x4 system like the Wrangler's Command-Trac means simply that it was designed primarily for offroad use and can't be used full time like when on paved streets. A Full-time 4x4 mode like the Cherokee's and Grand Cherokee's Selectrac system has in addition to part-time 4Hi and 4Lo 4x4 modes means it was designed so it can be used all the time, like on paved streets.

For example... the Selectrac 4x4 system available on Cherokees, Grand Cherokees, and Liberties has selectable part-time and selectable full-time modes. It has a 2wd, Full-time 4Hi, Part-time 4Hi, and Part-time 4Lo. You can select any of them, it's not in any particular mode unless you select it.

Part-time means the front and rear axles are mechanically locked together so no differentiation is allowed between the front and rear axles. This type of 4x4 system is designed for off-road use or extremely low traction situations like when paved roads are completely covered with snow or ice. That it is a part-time mode has no bearing on when you use it. The part-time mode term simply means it can't be used full-time since that would also include street use for which a part-time 4x4 system is not compatible.

A full-time 4x4 system places a differential between the front & rear axles so the front & rear axles can rotate at different speeds which makes it usable on paved high-traction surfaces. This is a selectable mode with the Selectrac 4x4 system used on Cherokees, Grand Cherokees, and Liberties. Other brands of vehicles also have selectable full-time 4x4 modes, not just Jeeps.

An AWD system is a full-time 4x4 system that is typically always in 4x4 with no 2wd mode.

Whether a system is part-time or full-time 4x4 has nothing to do with how often it is used. You may have a full-time 4x4 mode in a Jeep Cherokee and never use it, choosing to stay in 2wd all the time. Or it may only be used for that once a year trip up to the mountains... a full-time system that you select with the lever when it is needed for use on paved roads.

Jeep Grand Cherokee WJ - WJ Four-Wheel Drive Systems

Here is a photo of the Selectrac shifter with its selectable full-time and part-time 4x4 modes.

 

In other words, keep your lever pushed all the way forward into 2HI and make sure that part time light goes off while driving on a solid road. Pull back to 4HI when getting into snotty crap.

 

"Having a part-time 4x4 system like the Wrangler's Command-Trac means simply that it was designed primarily for offroad use and can't be used full time like when on paved streets." - AKA When you put it in 4x4, or Part time.

"A Full-time 4x4 mode like the Cherokee's and Grand Cherokee's Selectrac system has in addition to part-time 4Hi and 4Lo 4x4 modes means it was designed so it can be used all the time, like on paved streets." - AKA like an all wheel drive system like a Subaru.

Thanks for proving my point.

 

Can a Wrangler be shifted into 4WD while on the fly? I would not do it, but I am just curious.

 

You can switch back & forth between 2Hi and 4Hi at any legal/safe speed. It is a shift-on-the-fly system.

 

Your user manual actually wants you to be moving before switching into 4 high... I think it says up to 30...not 100% sure on the speed though.. You need to be at a complete stop to switch into 4 low

 

Ok. Good to know. Thanks.

 

and while were on the topic.. I had a full time Grand cherokee... while in full time 4wd.. it was in 2wd most of the time, until the unit felt less traction and sent power to the front wheels as needed.

 

The Chrysler SelecTrac does not shift torque. It is a very basic sysrem with a fixed split. I have the same system in my 99 Durango.

Not the analogy to a Subaru system is not correct. AWD and Full Time systems are generic automotive terms. Some are very complex in how power is shifted and others sytems sych as the above mentioned Chrysler are not. Subaru does shift torque (and I am sure Subaru has several kinds of systems out there.)

 

My wife's Grand Wagoneer has a full-time/part-time case. NP229 with a viscous coupler for 4-hi, and 4-lo is locked. It also has a 2wd setting.

No Wranglers have had a full-time system, ever, from the factory. 73 to 79 CJ-7's could be gotten with a full-time system, but that's the only SWB CJ that ever had the option that I'm aware of. That was the original Borg-Warner Quadra-Trac.

 

That makes a lot more sense now.

 

^^^ Welcome to the Forum!

 

Incorrect. Part time engages both front and back wheels, but the rear wheels are the drive wheels( the ones moving the jeep)...when the jeep feels slight traction issues it sends power to front wheels as well...when traction is stable- it takes the power away from the front wheels.
In Full time, all wheels are engaged and supply power to all wheels. This info is via MY OWNERSMANUAL!

 

Incorrect. Part time engages both front and back wheels, but the rear wheels are the drive wheels( the ones moving the jeep)...when the jeep feels slight traction issues it sends power to front wheels as well...when traction is stable- it takes the power away from the front wheels.

Absolutely and completely incorrect for any Wrangler. The Wrangler's 231 and 241 tcases power the front and rear wheels and split the power to them equally when in 4Hi or 4Lo. In a Wrangler, both axles are pulling 100% of the time when in 4Hi or 4Lo. There is no sensing anything.

Do some other 4x4 systems do that sensing business to send power to an axle or wheel when others are slipping? Yes, but the Wrangler does not. Its part-time only 231 and 241 transfer cases are very basic and have no ability to do that.

 

so much bad info in this thread, probably best to let it die

 

Thank you!!! ive been trying to figure out why that light is there!

 

welcome