Command Trac Question

gunflint · **Posted:** Mon Dec 11, 2006 7:57 am

I've been around 4 wheel drives for quit a while but I'm having a hard time grasping the part time / full time designation on the Liberty. (first Jeep) According to the Jeep web site, with a "Command Trac" set up when I shift into 4x4, 50% of the torque goes to the front and 50% to the rear. To me this means that I'm in full time 4 wheel drive. Yet the light on the dash says "Part Time." It's been said that my cognitive skills have been diminishing over the last few years, but what exactly is "part time" about this system? Thanks.

Taz · **Posted:** Mon Dec 11, 2006 8:31 am

Jeep uses the tag "Part Time" to refer to the use of this mode not the mechanics of the mode. In other words you should only drive in this mode part time, only on wet/slippery surfaces, not on dry surfaces with good traction. The mechanics of this system are like the old full time 4wd, the drive line is locked in 4wd.

gunflint · **Posted:** Mon Dec 11, 2006 8:58 am

I get it. It's more like a warning or caution light than a "This system is on light" Thanks.

Jeepnut · **Posted:** Mon Dec 11, 2006 10:33 am

also with the command trac there is a differential inside the case that allows some slipping until you put it in 4 lo where that diff locks solid like a standard case, I was thinking about using a Dana 300 with a flip kit in my 03, they have a lower gear ratio and a fixed output plus cost to co to lower gears in the case is cheaper than the NP231, has anyone tried this setup

Eddo · **Joined:** Thu Jul 07, 2005 7:01 pm **Posts:** 1214

Jeepnut wrote:

also with the command trac there is a differential inside the case that allows some slipping until you put it in 4 lo where that diff locks solid like a standard case, I was thinking about using a Dana 300 with a flip kit in my 03, they have a lower gear ratio and a fixed output plus cost to co to lower gears in the case is cheaper than the NP231, has anyone tried this setup

Actually, it's the selec-trac (242) that has the differential. The command trac (231) is locked (ie only part-time). Also, the 231 and 242 actually have a slightly lower gear ration than the Dana 300s (2.72:1 vs 2.6:1).

Gordo · **Posted:** Mon Dec 11, 2006 12:07 pm

Yeah, that designation messed me up for a while as well. I could have sworn that part-time 4wd meant that the Jeep was only using it part-time. But then I had to wonder why I didn't have the option for full-time... I finally got it figured out.

gunflint · **Posted:** Mon Dec 11, 2006 12:16 pm

Yeah, it seems like a soccer mom thing. "Only use 4 wheel part time." I'd like to see a dash light that says "hang up the phone" or "you're following to close."

jcphoto20 · **Joined:** Sun Nov 19, 2006 1:36 am **Posts:** 507

when we bought our jeep, the idiot dealer not only missed the almost inch of play in the steering wheel (needed a new steering box when it was brand new!) , but they also instructed us improperly that we should run it in part time 4x4 when on the street. we did so, and only on the hour and a half trip home. im just glad it was raining alot and i read the manual at home.

jbees · **Joined:** Thu Dec 07, 2006 2:45 pm **Posts:** 20

I missed the mark on the part time- full time story to. Picked up my Liberty in Portland, Or and headed home to Ak this month. When I hit the Canadan border there was snow on the road so figured part time was the thing to do. Drove it all day that way but when I stopped that night I took the time to read the book. Glad I did cause I left it in the fulltime 4X4 for the next 3 days. Went through some deep stuff in Hyder, AK and found there's lots of traction difference between the two. Part time digs in alot better in the deep and slippery.

Big D · **Joined:** Mon Jun 05, 2006 10:08 pm **Posts:** 349

It is quite suprising how many dealers are misinforming buyers on the correct use of the various Jeep 4x4 systems.

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