Repetitive clunking in 4 wheel drive

98 XJ Cherokee, 4.0, Selec-Trac (or whatever you call the one with part
time and full time)

Recently, leaving a driveway in the near-freezing rain I pulled the 4x4
handle all the way back into the full-time position. I happened to be
accelerating a bit as I did so, and I immediately heard/felt a
repetitive clunk-clunk-clunk that appeared to be coming from the
transfer case/trans area. I immediately backed off the throttle, and
the noise quit. So, again, to experiment I gave it a fair bit of gas
and again got the clunk-clunk-clunk sounds.
Mind you, this is not the expected clump sound/feel that you get when
it engages or disengages properly, but rather is louder and stronger.
The front feels like it is engaged, but anytime there is any load on
it, such as accelerating (even fairly gently) it gives me the
thump-thump-thump.
Of course, not knowing what was going on, I dropped it out of 4 and
took it home in 2 wheel.

I don't know if it could be related, but I just had the head gasket
replaced and had a valve job done at the same time. I've put on about
4,000 miles since then and, I'm becoming increasingly dissatisfied with
the shop's workmanship, as a relatively trouble-free vehicle has
quickly turned into a headache. I may or may not have run the four
wheel drive since then. (cant remember, if I did, it was once on snow.)

Any help is greatly appreciated.

Your clunk-clunk-clunk sounds like a U-joint or transfer case mount, but
with a recent valve job think about the exhaust hitting something under the
car. Does it feel as if something is hitting the floor?

Earle

"Jeff" > wrote in message
oups.com...
> 98 XJ Cherokee, 4.0, Selec-Trac (or whatever you call the one with part
> time and full time)
>
> Recently, leaving a driveway in the near-freezing rain I pulled the 4x4
> handle all the way back into the full-time position. I happened to be
> accelerating a bit as I did so, and I immediately heard/felt a
> repetitive clunk-clunk-clunk that appeared to be coming from the
> transfer case/trans area. I immediately backed off the throttle, and
> the noise quit. So, again, to experiment I gave it a fair bit of gas
> and again got the clunk-clunk-clunk sounds.
> Mind you, this is not the expected clump sound/feel that you get when
> it engages or disengages properly, but rather is louder and stronger.
> The front feels like it is engaged, but anytime there is any load on
> it, such as accelerating (even fairly gently) it gives me the
> thump-thump-thump.
> Of course, not knowing what was going on, I dropped it out of 4 and
> took it home in 2 wheel.
>
> I don't know if it could be related, but I just had the head gasket
> replaced and had a valve job done at the same time. I've put on about
> 4,000 miles since then and, I'm becoming increasingly dissatisfied with
> the shop's workmanship, as a relatively trouble-free vehicle has
> quickly turned into a headache. I may or may not have run the four
> wheel drive since then. (cant remember, if I did, it was once on snow.)
>
> Any help is greatly appreciated.
>

Hmm... something hitting the floor... it kinda does feel like that, and
thats about the right speed of thumping too. I'll check it after work
and get back to you.
Thanks!

On Dec 21, 5:56 pm, "Earle Horton" > wrote:
> Your clunk-clunk-clunk sounds like a U-joint or transfer case mount, but
> with a recent valve job think about the exhaust hitting something under the
> car. Does it feel as if something is hitting the floor?
>
> Earle
>
> "Jeff" > wrote in ooglegroups.com...
>
> > 98 XJ Cherokee, 4.0, Selec-Trac (or whatever you call the one with part
> > time and full time)
>
> > Recently, leaving a driveway in the near-freezing rain I pulled the 4x4
> > handle all the way back into the full-time position. I happened to be
> > accelerating a bit as I did so, and I immediately heard/felt a
> > repetitive clunk-clunk-clunk that appeared to be coming from the
> > transfer case/trans area. I immediately backed off the throttle, and
> > the noise quit. So, again, to experiment I gave it a fair bit of gas
> > and again got the clunk-clunk-clunk sounds.
> > Mind you, this is not the expected clump sound/feel that you get when
> > it engages or disengages properly, but rather is louder and stronger.
> > The front feels like it is engaged, but anytime there is any load on
> > it, such as accelerating (even fairly gently) it gives me the
> > thump-thump-thump.
> > Of course, not knowing what was going on, I dropped it out of 4 and
> > took it home in 2 wheel.
>
> > I don't know if it could be related, but I just had the head gasket
> > replaced and had a valve job done at the same time. I've put on about
> > 4,000 miles since then and, I'm becoming increasingly dissatisfied with
> > the shop's workmanship, as a relatively trouble-free vehicle has
> > quickly turned into a headache. I may or may not have run the four
> > wheel drive since then. (cant remember, if I did, it was once on snow.)
>
> > Any help is greatly appreciated.

"Jeff" > wrote in message
oups.com...
> 98 XJ Cherokee, 4.0, Selec-Trac (or whatever you call the one with part
> time and full time)
>
> Recently, leaving a driveway in the near-freezing rain I pulled the 4x4
> handle all the way back into the full-time position. I happened to be
> accelerating a bit as I did so, and I immediately heard/felt a
> repetitive clunk-clunk-clunk that appeared to be coming from the
> transfer case/trans area. I immediately backed off the throttle, and
> the noise quit. So, again, to experiment I gave it a fair bit of gas
> and again got the clunk-clunk-clunk sounds.
> Mind you, this is not the expected clump sound/feel that you get when
> it engages or disengages properly, but rather is louder and stronger.
> The front feels like it is engaged, but anytime there is any load on
> it, such as accelerating (even fairly gently) it gives me the
> thump-thump-thump.
> Of course, not knowing what was going on, I dropped it out of 4 and
> took it home in 2 wheel.
>
> I don't know if it could be related, but I just had the head gasket
> replaced and had a valve job done at the same time. I've put on about
> 4,000 miles since then and, I'm becoming increasingly dissatisfied with
> the shop's workmanship, as a relatively trouble-free vehicle has
> quickly turned into a headache. I may or may not have run the four
> wheel drive since then. (cant remember, if I did, it was once on snow.)
>
> Any help is greatly appreciated.
>

It is not related.

It sounds like a stretched chain in the tcase. The chain stretches when you
use 4WD on dry pavement. Well, not just dry, but any pavement where the
coefficient of friction is too great for the tires to slip on the ground and
release the stress that the tcase builds up.

If you really have Full Time 4WD, then your problem could be the viscous
coupler in the tcase.

"Jeff Strickland" > wrote in message
...
>
> "Jeff" > wrote in message
> oups.com...
> > 98 XJ Cherokee, 4.0, Selec-Trac (or whatever you call the one with part
> > time and full time)
> >
> > Recently, leaving a driveway in the near-freezing rain I pulled the 4x4
> > handle all the way back into the full-time position. I happened to be
> > accelerating a bit as I did so, and I immediately heard/felt a
> > repetitive clunk-clunk-clunk that appeared to be coming from the
> > transfer case/trans area. I immediately backed off the throttle, and
> > the noise quit. So, again, to experiment I gave it a fair bit of gas
> > and again got the clunk-clunk-clunk sounds.
> > Mind you, this is not the expected clump sound/feel that you get when
> > it engages or disengages properly, but rather is louder and stronger.
> > The front feels like it is engaged, but anytime there is any load on
> > it, such as accelerating (even fairly gently) it gives me the
> > thump-thump-thump.
> > Of course, not knowing what was going on, I dropped it out of 4 and
> > took it home in 2 wheel.
> >
> > I don't know if it could be related, but I just had the head gasket
> > replaced and had a valve job done at the same time. I've put on about
> > 4,000 miles since then and, I'm becoming increasingly dissatisfied with
> > the shop's workmanship, as a relatively trouble-free vehicle has
> > quickly turned into a headache. I may or may not have run the four
> > wheel drive since then. (cant remember, if I did, it was once on snow.)
> >
> > Any help is greatly appreciated.
> >
>
> It is not related.
>
> It sounds like a stretched chain in the tcase. The chain stretches when
you
> use 4WD on dry pavement. Well, not just dry, but any pavement where the
> coefficient of friction is too great for the tires to slip on the ground
and
> release the stress that the tcase builds up.
>
> If you really have Full Time 4WD, then your problem could be the viscous
> coupler in the tcase.
>
Selec-Trac doesn't have a viscous coupler, just an inter-axle differential.
Chain sounds likely too, but I'm still betting on exhaust hitting the body.

Earle

My bet is on a u-joint gone bad.

If the exhaust 'is' hitting, then check the engine mounts out
carefully. If the driver's side one goes on a 4.0, the exhaust will hit
the front driveshaft when under torque.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

Jeff wrote:
>
> 98 XJ Cherokee, 4.0, Selec-Trac (or whatever you call the one with part
> time and full time)
>
> Recently, leaving a driveway in the near-freezing rain I pulled the 4x4
> handle all the way back into the full-time position. I happened to be
> accelerating a bit as I did so, and I immediately heard/felt a
> repetitive clunk-clunk-clunk that appeared to be coming from the
> transfer case/trans area. I immediately backed off the throttle, and
> the noise quit. So, again, to experiment I gave it a fair bit of gas
> and again got the clunk-clunk-clunk sounds.
> Mind you, this is not the expected clump sound/feel that you get when
> it engages or disengages properly, but rather is louder and stronger.
> The front feels like it is engaged, but anytime there is any load on
> it, such as accelerating (even fairly gently) it gives me the
> thump-thump-thump.
> Of course, not knowing what was going on, I dropped it out of 4 and
> took it home in 2 wheel.
>
> I don't know if it could be related, but I just had the head gasket
> replaced and had a valve job done at the same time. I've put on about
> 4,000 miles since then and, I'm becoming increasingly dissatisfied with
> the shop's workmanship, as a relatively trouble-free vehicle has
> quickly turned into a headache. I may or may not have run the four
> wheel drive since then. (cant remember, if I did, it was once on snow.)
>
> Any help is greatly appreciated.

Jeff > wrote:
> Recently, leaving a driveway in the near-freezing rain I pulled the 4x4
> handle all the way back into the full-time position. I happened to be
> accelerating a bit as I did so, and I immediately heard/felt a
> repetitive clunk-clunk-clunk that appeared to be coming from the
> transfer case/trans area.
<snip>

My '98 Cherokee did that when the linkage was out of adjustment and it wasn't
"fully" engaged in 4WD.

The others could still be correct in that it is something more serious (chain,
u-joint, etc.), but I'd always start with the simple stuff and work from
there...

-John