Pt 4wd

[JViking]

I'm new to 4WD vehicles, and have purchased a Jeep Cherokee '91. I saw in this forum that max speed on Part Time 4WD is 35mph, so my question is when would you typically use PT? Why not use Full Time?

I would've thought that Part Time would be fine on highway driving, let's say during a snow fall, but when max speed is 35mph that's not an option.

I assume there's a need or else why would it be there :-)

[glennco1]

Part time on you selec trac system is mainly meant for off road driving. This is due to the fact that the transfers case locks the front and rear wheels together so they always turn at their respective rates, regardless of traction.

This can be problematic in highway driving due to the high level of traction provided by tar.

My cherokee had command trac, which did not have a full time setting, so I used part time on the tar. I also drove it over 35mph without a problem

[JViking]

Thanks! I found some info on the net regarding this, so I have a better understanding how the 4WD works.

[John Frassanito]

You can also use PT in the rain. The manual states that it is for loose slippery surfaces. I never used mine for 10 years because I don't go off road. Now if I use it I have a tough time getting it out so I just use 4WD instead. Also when you use PT and cut your wheels sharply your front wheel joints will flop back and forth. If I had my choice again I would get Command Track.

[JViking]

Originally Posted by John Frassanito

You can also use PT in the rain.

I found out the hard way that there's no weight above the rear axle the other day when I was about to pass a car in a tunnel, kicked down and suddenly I was just about looking straight into the wall. After that I use 4WD High when driving in the rain. Not sure it helps though, so I now drive a bit more carefully when it's raining.