Queston on 4WD

KJRenny · **Joined:** Wed Oct 19, 2005 10:52 pm **Posts:** 72

So I was "flexing" on a trailer:

and noticed that in 4 wheel drive(part time) and 4 wheel low, that is as high as I could go on the trailer, the drivers side rear would spin and it wouldnt go any farter, but neither of the fronts were spinning. In theory, as long as the 2 fronts have traction it should have pulled the truck up further, right?

AdamIsAdam · **Posted:** Mon Dec 05, 2005 11:18 pm

Are you sure the RF tire wasn't also slipping?

Are you sure you were totally engaged in 4WD?

KJRenny · **Joined:** Wed Oct 19, 2005 10:52 pm **Posts:** 72

yes and yes

Tokyojoe · **Posted:** Tue Dec 06, 2005 2:19 am

Well, if your KJ was farting, then it is a gas problem and you need to toss some beano into the tank. :lol:

Bri · **Posted:** Tue Dec 06, 2005 9:07 am

If a front tire wasn't spinning, you weren't in 4WD.

There shouldn't be any way you could be 4Lo without moving and not be spinning a front tire. Might need an extra person to walk around and check, that front passenger-side tire should have been spinning on the ground as well.

LibertyCRD · **Posted:** Tue Dec 06, 2005 9:17 am

This happens to me sometimes (I've almost gotten stuck because of it) and the problem is that apparently it takes a long time for the front drive shaft to engage once you select 4-part time. I don't know why...and it shouldn't....but it does. At least on mine.

Tightwadsjeeper · **Posted:** Tue Dec 06, 2005 9:24 am

I don't know what the problem is, but if neither of the front tires was spinning you were NOT in part-time 4WD.

Luis

KJRenny · **Joined:** Wed Oct 19, 2005 10:52 pm **Posts:** 72

Bri wrote:

If a front tire wasn't spinning, you weren't in 4WD.

There shouldn't be any way you could be 4Lo without moving and not be spinning a front tire. Might need an extra person to walk around and check, that front passenger-side tire should have been spinning on the ground as well.

well that would be the easiest answer, but this isnt the first 4x4 i've owned... It was def in 4WD... even if I couldnt figure out the shifter, the idiot light tells me too.

AdamIsAdam · **Posted:** Tue Dec 06, 2005 11:12 am

[quote="KJRenny]It was def in 4WD... even if I couldnt figure out the shifter, the idiot light tells me too.[/quote]

hehehe

It's called an idiot light for a reason. The light just confirms that you put the SHIFTER in to the 4WD position, but nothing indicates whether or not the transfer case actually engaged. glad to say you were not fully locked. I'm "glad" to say it because the alternative is that your tcase is broke. :roll:

jeepers · **Posted:** Tue Dec 06, 2005 11:36 am

well when did you put it in to 4wd? if you put it in 4wd when you found out it was spining you were not in 4wd instintly. it was menchend that it takes a wile for the 4wd to kick in. this is my thoughts on this. the reson it take a short distence to go into 4wd is becasue its a shift on the fly t-case. what i mean is you can put it into 4wd wile you are driving as long as you are 55mph or less(full time 4wd & part time 4wd only!). well if it didn't have lag time it would rip the t-case apart.if you were to put in into 4wd and then drive about 10+ feet it would be fine and you wouldn't have any issue. if iam wrong let me know, when you try this agian witch i know you will :wink:

just put it in 4wd 10+ feet before getting on the trailer and see how it works.

Spowers · **Posted:** Tue Dec 06, 2005 12:57 pm

One thing I have noticed with the 4wd engagement, it really takes a long time. In addition, with the snow on the ground, I have to go to Neutral then to drive to "help" everything engage. I am currently writing this off as "new" break in, but it is a far cry from my Instant-on of the Wrangler.

Any one else seeing this?

BTW nice call on the Bean-O

dog_party · **Posted:** Tue Dec 06, 2005 4:41 pm

If I recall correctly, the manual says something about occasionally having to put the vehicle in reverse, back up a few feet, then back into drive before 4WD will engage if you're stationary...or something like that. Did you back down the ramp and then try it again? Same results? If so, your T-case might BE broken.

Next time, try shifting into 4-PartTime 10 feet from the ramp while doing 54MPH, preload the suspension and then go "yeeeeehawwwwww!"

JediJeeper · **Posted:** Tue Dec 06, 2005 7:23 pm

As with most "part time" transfer cases, when they are engaged in part time there is a differential in between the front and rear outputs. Which means that if one tire is off the ground or spinning, whether it be front or rear, that is where all the power will go and be lost. Placing the T-case into "full time" locks this front to rear diff and that is when you would have the behaviour you expected to see.

-Adam

DavidG · **Posted:** Tue Dec 06, 2005 9:37 pm

JediJeeper
As with most "part time" transfer cases, when they are engaged in part time there is a differential in between the front and rear outputs. Which means that if one tire is off the ground or spinning, whether it be front or rear, that is where all the power will go and be "LOST". Placing the T-case into "full time" locks this front to rear diff and that is when you would have the behaviour you expected to see.

I believe that is backwards. "Part Time," the only mode available in Command Trac, means that you can use it part time, i.e. when there is low traction all around. In that case the front and back are locked together and the low traction allows the front or back tires to slip. "Full Time," available only on Selec Trac, has the differential between the front and back to allow the speed to vary between them. That can be used full time even in high traction scenarios.

KJRenny · **Joined:** Wed Oct 19, 2005 10:52 pm **Posts:** 72

^
he is correct. To answer the question if I backed up, moved 10 feet, put it in neutral and then hit the ramp 2 times? no. I put it in part-time about 5 feet from the ramp while rolling(3-5mph in neutral). SO I guess as stated above, our t-case is a far cry from the wranglers

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

KJRenny wrote:

^
he is correct. To answer the question if I backed up, moved 10 feet, put it in neutral and then hit the ramp 2 times? no. I put it in part-time about 5 feet from the ramp while rolling(3-5mph in neutral). SO I guess as stated above, our t-case is a far cry from the wranglers

The 231 (part time only t-case) is the same as in the wrangler. The 242 (fulltime and par time t-case) is used in ZJs, WJs and XJs. It take a bit to lock or unlock that center diff at times, because you don't physically shift the case into 4 hi. You simple pre-tension a spring attached to a fork that shift it into 4wd. However, it is different with 4-lo I believe. So next time try just poping here into 4-lo and you shouldn't have that problem. If you are climbing a ramp like that 4-lo will make it eaiser on the tranny and give you more control anyways.

AdamIsAdam · **Posted:** Wed Dec 07, 2005 9:51 am

well put.

KJRenny · **Joined:** Wed Oct 19, 2005 10:52 pm **Posts:** 72

nice call

Myke · **Posted:** Thu Dec 08, 2005 1:40 am

LibertyCRD wrote:

This happens to me sometimes (I've almost gotten stuck because of it) and the problem is that apparently it takes a long time for the front drive shaft to engage once you select 4-part time. I don't know why...and it shouldn't....but it does. At least on mine.

This happens to mine also it takes a few minutes to engage it but I found out that if your on semi-stiff terrain just floor tap the gas a few times and it should click it in.

JediJeeper · **Posted:** Thu Dec 08, 2005 12:50 pm

DavidG wrote:

I believe that is backwards. "Part Time," the only mode available in Command Trac, means that you can use it part time, i.e. when there is low traction all around. In that case the front and back are locked together and the low traction allows the front or back tires to slip. "Full Time," available only on Selec Trac, has the differential between the front and back to allow the speed to vary between them. That can be used full time even in high traction scenarios.

Let me find you an exploded view, I am not talking about the literature, I am speaking as to how the compenents inside are working. I am not completely familiar with the "part time" only T-cases that are used in KJs today, in this case I am referring to the 242 that has both part and full ltime. But even in the case of the old quadra-trac part time T-cases that jeep used it was a biased link between the front and rear output, hence you could get a grand cherokee stuck with only one wheel slipping (until you twisted the front/rear lock nob, which activated a pneumatic servo and applied a lock ring very similar to an ARB lock ring over the front to rear diff).

I will get back to you guys.
-Adam

Queston on 4WD

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