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-   -   Transmission Issue...Maybe (http://www.jeepgarage.org/f181/transmission-issue-maybe-44429.html)

No One 07-08-2012 12:09 PM

Transmission Issue...Maybe
 
This post is from another Jeep forum, any of you gurus have an idea how this would happen on a WK with QDII? I have never heard of this particular problem.

Quote:

Turning right onto freeway ...loud clunk and it died --engine runs and revs increase but will not go. Same in R and P. Grinding noise too. Would only go in low range which got me to a dealer. Anyone know how it could work in Lo and not in normal drive? It sounded like something broke but how would it work in Lo for about 15 miles? I'm stumped

Frango100 07-08-2012 12:18 PM

Re: Transmission Issue...Maybe
 
Not familiar with the WK, but the Low range is that first gear, or is he talking about Low range on the T-case?

No One 07-08-2012 01:26 PM

Re: Transmission Issue...Maybe
 
T-Case

Scottina06 07-08-2012 02:00 PM

Re: Transmission Issue...Maybe
 
sounds like a sprag is broken...probably forward. Time for a new tranny or rebuild

Frango100 07-08-2012 02:24 PM

Re: Transmission Issue...Maybe
 
Normally with the T-case in 4-Hi, the torque goes to the rear wheels. Only when a certain speed difference in between front and aft propeller shaft is detected, part of the torque is directed to the front propeller shaft.
In Lo range, the front propeller shaft is directly driven together with the aft propeller shaft. So when the jeep doesn't drive in 4-Hi, there could be something broken in the T-case, but also in the aft differential. When then 4-Lo is selected, torque goes to the front wheels and the jeep can be driven.
So doesn't seem to have to do with the tranny.

dr.lee.baugh 07-08-2012 02:32 PM

Re: Transmission Issue...Maybe
 
Quote:

Originally Posted by Frango100 (Post 653559)
Normally with the T-case in 4-Hi, the torque goes to the rear wheels. Only when a certain speed difference in between front and aft propeller shaft is detected, part of the torque is directed to the front propeller shaft.
In Lo range, the front propeller shaft is directly driven together with the aft propeller shaft. So when the jeep doesn't drive in 4-Hi, there could be something broken in the T-case, but also in the aft differential. When then 4-Lo is selected, torque goes to the front wheels and the jeep can be driven.
So doesn't seem to have to do with the tranny.

I'm not sure this is completely true. I believe in 4-Hi the drivetrain is rear wheel biased, but something like 48% of the torque is still directed to the front, Under slip this percentage front to back can vary, but under normal driving it is still outputting torque to the front. At least that's the way it is with the NV245 case.

I would tend to agree wih Scott, and be looking at the transmission itself as a probable cause...I suppose it could be something internal in the transfer case, but I'm not sure what in its inner-workings would allow 4-lo to function while 4-hi does not.

4.whoa 07-09-2012 06:58 AM

Re: Transmission Issue...Maybe
 
On the reg GC the t/c does not put a specific amount to the front or rear at all times i had my front shaft out and was going to leave it out because the ujoint wasn't perfect,but it WOULD NOT GO ! with the trans in park,i could push it around the garage, and in gear it just spun the front t/c output.
I agree with the 4-lo locking it (t/c) up. I bet something in a diff let go

dr.lee.baugh 07-09-2012 08:42 AM

Re: Transmission Issue...Maybe
 
Quote:

Originally Posted by 4.whoa (Post 653853)
On the reg GC the t/c does not put a specific amount to the front or rear at all times i had my front shaft out and was going to leave it out because the ujoint wasn't perfect,but it WOULD NOT GO ! with the trans in park,i could push it around the garage, and in gear it just spun the front t/c output.
I agree with the 4-lo locking it (t/c) up. I bet something in a diff let go

According to the FSM it does:


"The NV245 transfer case provides Full-Time Active Four-Wheel Drive for optimum traction in a wide range of conditions and is used in Quadra-TracII and Quadra-DriveII systems. The transfer case center differential distributes torque 48 percent to the front axle and 52 percent to the rear axle along with an electronically controlled clutch pack that is coupled to the center differential for torque biasing. The NV245 electronics provide an active system because it can anticipate and prevent slip. The transfer case can redistribute 100 percent of torque to the front or rear axle, depending on need. For added traction when traversing steep grades, rough terrain or extremely slippery/poor traction surfaces at low speeds, the transfer case can be switched into 4WD Low, which multiplies engine torque 2.72 times and locks the clutch pack for maximum traction at all times. The Neutral mode allows the vehicle to be flat towed behind another vehicle."

I would imagine removing your front drive shaft prevents the computer from receiving appropriate readings from various sensors, and that is what prevented your rig from moving...

Like I said I don't know much about the inner-workings of the tranfer case, and it could be the cause, but do know it is sending power to both the front and read during normal operation.


TaosBob 07-09-2012 07:31 PM

Re: Transmission Issue...Maybe
 
I am the one with the above problem.
I actually have Quadra Trac II, not Quadra Drive II if that makes any difference.
The clunk was very loud and seemed to come from the front. I could not move in D or R and there was a spinning sound, as if something had become disconnected. I tried Lo range and that worked, D and R. I drove it 15 miles and it shifted properly, or at least the way it does in Lo range.
It is sitting at a dealership 300 miles away so I can not look at it to check anything out.
Any help would be greatly appreciated.

Bob

dr.lee.baugh 07-09-2012 10:20 PM

Re: Transmission Issue...Maybe
 
Both quadra trac and quadra drive use the nv245, I believe.

But, based on what you say, I'd change my vote to transfer case as well...I have no idea what inside there could cause what you desceibe, but it sounds more likely than transmission, IMO.

Be prepared for a big repair bill...cheaper than a transmission rebuild, but still an expensive component.
Depending on the age/condition of the vehicle, you may want to consider putting in a good, low-mileage used case if that turns out to be the cause.

Good luck!

2005JGC 07-09-2012 11:30 PM

Re: Transmission Issue...Maybe
 
You may have broken an axle in the front... the torque split in the transfercase is an open style (not technical terminology mind you), so if ANY path to the pavement is lost it will just spin and not send power to the ground, in 4lo it locks the transfercase so you have a dedicated locked path to the ground in the front and rear. Considering you heard the noise up front and your large lift and known cv issues with big lifts on these, Im guessing its an axle up front.

TaosBob 07-10-2012 09:37 AM

Re: Transmission Issue...Maybe
 
Quote:

Originally Posted by dr.lee.baugh (Post 654303)
Be prepared for a big repair bill...cheaper than a transmission rebuild, but still an expensive component.
Depending on the age/condition of the vehicle, you may want to consider putting in a good, low-mileage used case if that turns out to be the cause.

Thank you. I have an extended warranty so it should be 100% covered.

Mileage is only 39,000 so nothing should be breaking but....


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