Hey everyone, hope somebody knows the answer to this one. I have a 1995
Jeep Grand Cherokee Limited with a 5.2L V8, full-time 4wd. It has an
automatic with the NP249 transfer case. When I drive it, especially at
70mph or more for a mile or so, the Jeep starts making a thumping sound
in the driveline and something is trying to bind up because I can hear
the tires faintly screeching on the asphalt. The first time it
happened, I thought I had a flat. It was that kind of sensation. I can
pull to a stop, then take right back off and things are fine until my
speed comes up, then all over again. I can hear it affecting my
driveline, sounds like somebody pecking on my driveshaft with a small
hammer. Here is what I have replaced so far:

Rear driveshaft U-joints
Front driveshaft from end to end
Front axles
Front spider gears

None of these have helped which has led me to believe it is the
transmission or transfer case. Anybody have any ideas?

Thanks,
Derrick

 

Sounds like a classic VC problem in the np249.


"Hillbillyd" <derrickharderson@hotmail.com> wrote in message
news:1155708851.654443.264300@74g2000cwt.googlegro ups.com...
> Hey everyone, hope somebody knows the answer to this one. I have a 1995
> Jeep Grand Cherokee Limited with a 5.2L V8, full-time 4wd. It has an
> automatic with the NP249 transfer case. When I drive it, especially at
> 70mph or more for a mile or so, the Jeep starts making a thumping sound
> in the driveline and something is trying to bind up because I can hear
> the tires faintly screeching on the asphalt. The first time it
> happened, I thought I had a flat. It was that kind of sensation. I can
> pull to a stop, then take right back off and things are fine until my
> speed comes up, then all over again. I can hear it affecting my
> driveline, sounds like somebody pecking on my driveshaft with a small
> hammer. Here is what I have replaced so far:
>
> Rear driveshaft U-joints
> Front driveshaft from end to end
> Front axles
> Front spider gears
>
> None of these have helped which has led me to believe it is the
> transmission or transfer case. Anybody have any ideas?
>
> Thanks,
> Derrick
>

 

Sounds like a classic VC problem in the np249.


"Hillbillyd" <derrickharderson@hotmail.com> wrote in message
news:1155708851.654443.264300@74g2000cwt.googlegro ups.com...
> Hey everyone, hope somebody knows the answer to this one. I have a 1995
> Jeep Grand Cherokee Limited with a 5.2L V8, full-time 4wd. It has an
> automatic with the NP249 transfer case. When I drive it, especially at
> 70mph or more for a mile or so, the Jeep starts making a thumping sound
> in the driveline and something is trying to bind up because I can hear
> the tires faintly screeching on the asphalt. The first time it
> happened, I thought I had a flat. It was that kind of sensation. I can
> pull to a stop, then take right back off and things are fine until my
> speed comes up, then all over again. I can hear it affecting my
> driveline, sounds like somebody pecking on my driveshaft with a small
> hammer. Here is what I have replaced so far:
>
> Rear driveshaft U-joints
> Front driveshaft from end to end
> Front axles
> Front spider gears
>
> None of these have helped which has led me to believe it is the
> transmission or transfer case. Anybody have any ideas?
>
> Thanks,
> Derrick
>

 

Sounds like a classic VC problem in the np249.


"Hillbillyd" <derrickharderson@hotmail.com> wrote in message
news:1155708851.654443.264300@74g2000cwt.googlegro ups.com...
> Hey everyone, hope somebody knows the answer to this one. I have a 1995
> Jeep Grand Cherokee Limited with a 5.2L V8, full-time 4wd. It has an
> automatic with the NP249 transfer case. When I drive it, especially at
> 70mph or more for a mile or so, the Jeep starts making a thumping sound
> in the driveline and something is trying to bind up because I can hear
> the tires faintly screeching on the asphalt. The first time it
> happened, I thought I had a flat. It was that kind of sensation. I can
> pull to a stop, then take right back off and things are fine until my
> speed comes up, then all over again. I can hear it affecting my
> driveline, sounds like somebody pecking on my driveshaft with a small
> hammer. Here is what I have replaced so far:
>
> Rear driveshaft U-joints
> Front driveshaft from end to end
> Front axles
> Front spider gears
>
> None of these have helped which has led me to believe it is the
> transmission or transfer case. Anybody have any ideas?
>
> Thanks,
> Derrick
>

 

Sounds like a classic VC problem in the np249.


"Hillbillyd" <derrickharderson@hotmail.com> wrote in message
news:1155708851.654443.264300@74g2000cwt.googlegro ups.com...
> Hey everyone, hope somebody knows the answer to this one. I have a 1995
> Jeep Grand Cherokee Limited with a 5.2L V8, full-time 4wd. It has an
> automatic with the NP249 transfer case. When I drive it, especially at
> 70mph or more for a mile or so, the Jeep starts making a thumping sound
> in the driveline and something is trying to bind up because I can hear
> the tires faintly screeching on the asphalt. The first time it
> happened, I thought I had a flat. It was that kind of sensation. I can
> pull to a stop, then take right back off and things are fine until my
> speed comes up, then all over again. I can hear it affecting my
> driveline, sounds like somebody pecking on my driveshaft with a small
> hammer. Here is what I have replaced so far:
>
> Rear driveshaft U-joints
> Front driveshaft from end to end
> Front axles
> Front spider gears
>
> None of these have helped which has led me to believe it is the
> transmission or transfer case. Anybody have any ideas?
>
> Thanks,
> Derrick
>

 

Hey, not sure exactly, but try this little test. Drive it around at normal
speed and let things warm up...then do this test.

Exit the roadway and make a tight turn at slow speed
(best described as if you were pulling into a Mickey Dee's drive-thru
sharp turns), this will make your front axles and rear axles turn at
different rates; if it feels like the front is dragging across the pavement
with a binding sensation, then its the VC. The VC splits the power between
the front and rear drivetrains in the TC.

Do a google search on NP249 Viscous Coupler.

This is a known problem with the NP249....there are options as to replace it
(VC) or swap in another model transfer case.

Hope this helps you figure it it out....I just went thru a similar
situation....

T

 

Hey, not sure exactly, but try this little test. Drive it around at normal
speed and let things warm up...then do this test.

Exit the roadway and make a tight turn at slow speed
(best described as if you were pulling into a Mickey Dee's drive-thru
sharp turns), this will make your front axles and rear axles turn at
different rates; if it feels like the front is dragging across the pavement
with a binding sensation, then its the VC. The VC splits the power between
the front and rear drivetrains in the TC.

Do a google search on NP249 Viscous Coupler.

This is a known problem with the NP249....there are options as to replace it
(VC) or swap in another model transfer case.

Hope this helps you figure it it out....I just went thru a similar
situation....

T

 

Hey, not sure exactly, but try this little test. Drive it around at normal
speed and let things warm up...then do this test.

Exit the roadway and make a tight turn at slow speed
(best described as if you were pulling into a Mickey Dee's drive-thru
sharp turns), this will make your front axles and rear axles turn at
different rates; if it feels like the front is dragging across the pavement
with a binding sensation, then its the VC. The VC splits the power between
the front and rear drivetrains in the TC.

Do a google search on NP249 Viscous Coupler.

This is a known problem with the NP249....there are options as to replace it
(VC) or swap in another model transfer case.

Hope this helps you figure it it out....I just went thru a similar
situation....

T

 

Hey, not sure exactly, but try this little test. Drive it around at normal
speed and let things warm up...then do this test.

Exit the roadway and make a tight turn at slow speed
(best described as if you were pulling into a Mickey Dee's drive-thru
sharp turns), this will make your front axles and rear axles turn at
different rates; if it feels like the front is dragging across the pavement
with a binding sensation, then its the VC. The VC splits the power between
the front and rear drivetrains in the TC.

Do a google search on NP249 Viscous Coupler.

This is a known problem with the NP249....there are options as to replace it
(VC) or swap in another model transfer case.

Hope this helps you figure it it out....I just went thru a similar
situation....

T