Full time 4wd or not?!?

Full-time on your Cherokee means just that, full-time... both axles are engaged all the time when you're in any of the 4x4 settings. Yes, the full-time position is the correct one to use on the roads and its use will not damage the transfer case, that's what it was designed to do.

Jerry

I had assumed it was one of those systems that only engaged when the wheels slipped. Good news that I was wrong

What is different about the full-time setting than the part time then? If they both engage the front axle...

Thanks!

Eric

One way to explain it is that full time four wheel drive engages the front axle, but part time four wheel drive ENGAGES the front axle. Part time locks the front and back axles together, not the best thing for a paved road.

Earle

The part-time (4Hi and 4Lo) settings mechanically lock the front and rear axles together. They turn in lock-step with each other. This is the more aggressive of the two modes, part and full-time, and is used for offroading.

The full-time setting couples the front and rear axles together via a viscous (fluid) coupling, much like how an automatic transmission works. This is a less "aggressive" 4x4 mode that allows for some slippage between the front and rear axles that is required for paved highway use.

Jerry

In Full Time you have engaged the center differential in the transfer case, which helps to eliminate front/ rear axle binding. You can still feel it a little as the steering wheel twitches during sharp turns.

The center diff is _not_ a limited slip in the XJ, so you can still get one wheel spinning with all the available power. That's why the Part Time postion is a better choice for when it is snowy. If it's raining or icy with bare patches, keep it in Full Time. If your wife is clueless, keep it in Full Time.

John Davies Spokane WA USA

Is there a reason the same transfer case isn't used in the TJ? Sounds like a good option to have to me.

I use part time whenever we take the XJ on the trails, and use it when the weather is nasty (i.e. WAY too much snow). I try to avoid putting the TJ in

4wd unless the weather is nasty or I'm crawling over some rock. Even on the trails I'll put it in and out of 4wd when I don't need it.

Eric

99 TJ

• * * Matt Macchiarolo
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Good guess, you are right, it is too long to fit.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's

Matt Macchiarolo wrote:

The Cherokee's full-time system is not an AWD (a reactive 2wd system that engages the other axle when slippage is noted), it's a much simpler purely mechanical full-time 4wd system which is different from AWD. I don't recall my long-gone Cherokee ever pulling when it was in full-time 4wd, perhaps there's a bad u-joint on one of the front axleshafts.

Jerry

-- Jerry Bransford To email, remove 'me' from my email address KC6TAY, PP-ASEL See the Geezer Jeep at

The only time I noticed a difference was during slow, sharp turns on pavement. The difference is that I'm-in-4wd feeling when you turn. I only recognize it because if I'm on the trail and take a sharp turn in the TJ it does the same thing. The wheels... twitch.. for lack of a better way to put it... once every rotation or two. Again, this is only in SHARP turns on pavement.

Full time doesn't lock the inside and outside tires (as much). I've had mine

96 xj in full time 4wd for most of its 140,000 miles so far.. I think the only time it goes in 2wd is when i drove it off the lot, when i take it in for an oil change - those mechanics love to put it in 2wd, and when its in part time 4wd on the sand...

Why the name change, "valued user"?!? Alhtough it IS appropriate.. ;-)

name change??

Nope, and I'm sorry, but I don't even know what that means.

John Davies Spokane WA USA

According to the 2000 Jeep Cherokee brouchure... "Part-Time 4X4 splits power

50/50 between the front and rear axles. Full-Time 4X4 splits the power 48 front/52 rear. This allows the Cherokee to be driven in Full-Time 4X4 in all weather conditions, even dry pavement, without harming the drivetrain."

On tight turns you will notice a little binding in full-time...but 48/52 gives the system enough play to not harm the linkage.

The Select-trac tansfer case is too large to fit into a Jeep Wrangler in it's current form. Word is a new Slect-Trac II (even though the current version is the 3rd version I believe?) will be fitted into 2005 Cherokee/Grand Cherokee/Wagoneer.

-Mark

89YJ

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I'm sorry, I assumed you were Nathan. I thought I saw a post somewhere with "Valued User" (see header below) and Nathan's signature block. My mistake.