99 grand cherokee 4x4 disengaged

kumijia · 01-27-2012, 03:24 PM

Is there a way to disengage the four wheel drive on a 99 grand Cherokee? My full time 4x4 doesn't work, i have to put it in low and i can only too like 20 miles an hour. I saw somewhere that Subaru had a fuse that would disengage the awd, does jeep have this same type of fuse? I searched online, and was only able to find a possibly of the lever just not engaging on the tranny...The full time has never worked in the 8 years i've owned the vehicle. Maybe someone on this forum has the answer..

**Double E** · 01-27-2012, 04:05 PM

More info please. Do we assume you have the Selec-Trac?

What information have you gathered that indicates FT is not working? Does it bind up when turning ...or do the front wheels not engage when on slippery conditions?

When you say disengage, do you mean remove the front DS or deactivate the ability to detect slip?

Are you unable to drive it at all over 20mph ...or can you drive it over 20mph in FT mode but FT does not also activate when it should?

kumijia · 01-27-2012, 08:25 PM

Quote:

Originally Posted by Double E

More info please. Do we assume you have the Selec-Trac?

What information have you gathered that indicates FT is not working? Does it bind up when turning ...or do the front wheels not engage when on slippery conditions?

When you say disengage, do you mean remove the front DS or deactivate the ability to detect slip?

Are you unable to drive it at all over 20mph ...or can you drive it over 20mph in FT mode but FT does not also activate when it should?

I believe it's a slec-trac, but not 100% sure. I'll have to check. I was under the impression it's always in 4x4, or like an awd system. My front wheels never engage. I can spin the rear wheels all i want. It's only 2 wheel drive. If i get stuck, i have to put the tranny in neutral, take the 4x4 shifter and select low and then i have 4x4 but can't go over a 20 mph speed because it revs the engine very high. So i know the 4x4 works, just not when the rear slips. Since i bought the vehicle used, i wonder is someone disabled it for some unknown reason. So i guess to remove the ability to detect slip. The drive the vehicle everyday, and have no other problems. It's just if it snows, i only have 2 wheel drive....

mctwin2kman · 01-28-2012, 03:59 AM

What does you shifter say? Select Track II or QuardaDrive?

kumijia · 01-28-2012, 06:43 AM

Quadra trac II

mctwin2kman · 01-28-2012, 08:41 AM

Sounds like your progressive coupler is shot, like mine. You can either do a swap to a 242 Select Trac one or replace the coupler.

Brian321 · 01-28-2012, 10:43 AM

Quote:

Originally Posted by mctwin2kman

Sounds like your progressive coupler is shot, like mine. You can either do a swap to a 242 Select Trac one or replace the coupler.

Is it hard to replace the coupler myself? I have the same problem with my jeep.

**rm2001wj** · 01-28-2012, 11:15 AM

The QTII (NV247) transfer case is entirely mechanical, and there is no switch to turn on or off.

There is a possibility that it is working but conditions are such that you don't notice it working. QTII will send power to the front differential if only one of the rear wheels slips. The normal rear differential with QTII is an open type which means if one wheel loses traction the other wheel will get only a small torque that probably won't be enough to drive that wheel; so that wheel turns slowly or not at all. The front differential is also an open type. Even when power is sent to the front differential, one wheel can spin if traction is lost at that wheel, and the other wheel will rotate slowly or not at all. What all this means is that if one rear wheel and one front wheel both slip at the same time, you are stuck. If you can't see the rotating and slipping front wheel, you would think the transfer case is not working correctly. Unfortunately, that 4 ALL TIME on the shift bezel doesn't mean 4x4 or 4WD all the time under all conditions.

Another thing is that, depending on the conditions, it may require a significant amount of power going to the front in order to move the vehicle. In that case the engine speed needs to get fairly high. Don't be afraid to push the accelerator pedal down a pretty good bit.

To really see if the QTII is working, find a place where the rear wheels will spin (little or no traction), but both front wheels will have good traction. It works if the front wheels will move you.

A final comment concerns servicing the transfer case with the correct lubricant. If you haven't been using the NV247 lubricant from the Jeep dealership, then switching to that lube might help. If the progressive coupler is indeed shot, the correct lubricant won't help at all.

kumijia · 01-28-2012, 06:35 PM

i can have my rear wheels on grass and my front a macadam, and spin the *** of the rear tires, the front will never engage. What is the coupler that may need to be replaced? Is there a diagram, or a how to?

Brian321 · 01-28-2012, 07:07 PM

Quote:

Originally Posted by kumijia

i can have my rear wheels on grass and my front a macadam, and spin the *** of the rear tires, the front will never engage. What is the coupler that may need to be replaced? Is there a diagram, or a how to?

I have the same problem, I can have all four on flat pavement and just roast the back tires.

**rm2001wj** · 01-28-2012, 07:10 PM

That confirms that the TC is not working properly. I don't have any experience with this, but I'm pretty sure that replacing the progressive coupler involves removing the TC and tearing it apart.

If some lubricant other than the Mopar NV247 lube has been used in the TC, it might be worthwhile draining out that lubricant and replacing it with the special Mopar lube. That just might bring it back to life. You would need to drive maybe a couple hundred miles to get any change if there is actually going to be one.

Your use of the word "macadam" is interesting and not something I remember anyone using except in literary writings. I like it.

kumijia · 01-28-2012, 09:11 PM

Quote:

Originally Posted by rm2001wj

That confirms that the TC is not working properly. I don't have any experience with this, but I'm pretty sure that replacing the progressive coupler involves removing the TC and tearing it apart.

If some lubricant other than the Mopar NV247 lube has been used in the TC, it might be worthwhile draining out that lubricant and replacing it with the special Mopar lube. That just might bring it back to life. You would need to drive maybe a couple hundred miles to get any change if there is actually going to be one.

Your use of the word "macadam" is interesting and not something I remember anyone using except in literary writings. I like it.

LOL thank you, when i was a kid, my dad and i were at in the sticks in the middle of no where looking for MacAdam road. When we couldn't find it, we asked a local farmer where the road was.....He said MacAdam? You're on it...all the other roads around here are dirt....HAHAHAHA Being in different parts of Northeast PA, you hear all kind of slang terms, and i find myself using them more often then not.

This Mopar lube, what exactly is that, i run ATF that is made for Chrysler...is that what we are talking about, or something totally different? Also by TC i assume that is the Torque converter?

**rm2001wj** · 01-28-2012, 10:38 PM

Quote:

Originally Posted by kumijia

...................

This Mopar lube, what exactly is that, i run ATF that is made for Chrysler...is that what we are talking about, or something totally different? Also by TC i assume that is the Torque converter?

Sorry about confusion, I started using TC instead of transfer case because it's easier. The Mopar NV247 transfer case lube is similar to but significantly different from the ATF+4 used in the transmissions. In 99 ATF+4 was put into the QTII transfer cases at the factory, but soon problems occurred and a new lubricant developed to eliminate the problems. The QTII transfer case is known as the NV247, and the lube was labelled as NV247 lubricant. Mopar is the Chrysler brand of parts and fluids. A trip to a Chrysler/Dodge/Jeep dealership is necessary to get the NV247 lube; the various auto parts stores don't sell it.

kumijia · 01-28-2012, 11:31 PM

Well it seems like changing the fluid, may correct the problem, or at least can't hurt to try. I've never done anything to the TC, and i doubt previous owners did either. The vehicle was leased, and does have one or two recall stickers under the hood, but i doubt it was for that. Another question to help me figure things out...this coupler that was mentioned before, If that is bad would my 4*4 work when i select it to low, also would it make noise anytime when driving?

I was talking to a coworker of mine and he had the front drive shaft go out on his 03 liberty a couple months ago. His mechanic said one U joint is replaceable, the other (farthest one up front) wasn't, it's pressed in to the case. Now i know the liberty is different then the GC but is this essentially the "coupler?" His also made noise, and eventually stopped shifting out of second gear. Now, his mechanic i don't really trust...LOL but maybe it'll give me an idea of what i have going on. My jeep doesn't make any noise when driving, you don't even know something is wrong, until the rear tires slip.

**darule336** · 01-28-2012, 11:56 PM

I am sort of going through the same thing with my 4x4 system also have the QTII 247 transfer case. My main issue with mine was the binding on tight turns. Changed my fluid, which is supposed to be changed like every 20k miles. Owned my wj for the last 50k and never changed the fluid. Figured it was worth a shot, got rid of 95% of the binding. I think my Tc is engaging the front now, just not very quickly.

I would pick of the nv247 fluid from the dealership. Little expensive but if it works it a lot less then a swap or a rebuild.