I've got a 97 cherokee sport with the 4.0 and the NP231 transfer case, and have noticed that on hard acceleration (like from 0 to 15 or 20 at WOT) there is an intermittent knocking which seems to be coming from the lower-center console area, and can be felt in the floor.

It is made several times worse accelerating hard through a turn when a wheel looses traction, or when a wheel looses traction on straight acceleration.

I know that these transfer cases have all sorts of magical differentials and slips which send more power to the front when the rear looses traction, but these issues all happen in 2 wheel drive...

Could it be a transfer case chain thats loose and skipping?

Any input welcome.

Thanks!

 

Check your transmission mount. Mine was shot and caused the entire drivetrain to move around freely causing all sorts of clunking and vibrations

 

No. They are not magical. It's pronounced mechanical. It's probably not your TC if your in 2wd. You sure it's not your engine knocking.. The way your drivin? You know it's a jeep not a civic right?
That said, check your DS to see if it has any movement in it. What about the front end? Bushings, TRE's, bearings, joints. I hope it's not a worn out R/P...

And x2 on mounts. ^^^

 

Yes, I'm sure its not my engine knocking.
I take great care of my jeep and the engine runs like a champ.
And I'm not a seasoned forum hawk here. Please save the lazy acronyms for advanced tech, I don't know what DS or R/T means. For all I know, you made them up to mess with me.

I came with a simple symptom, and am looking for a diagnosis. I'll drive my jeep fast, you guys can drive yours over mountains. I'll leave your ways alone, you let mine be.

 

Its not a front-end noise, it is definitely coming from the transmission/transfer case area.

 

Ok. I'm sorry. Didn't mean to insult. The terms are def not fake! DS is drive shaft and R/P is ring and pinion.
Edit- and don't call me lazy. I'm the only one posting for ya.. So I'm tryin..

 

Didn't mean to sound too terribly irritated. Thanks for the help,
I've checked the u-joints which are all in good shape, and I don't see any sign of scarring or drive shaft interference with anything, but the exhaust in particular.
I'm not sure what else it could be.

When I'm under the car, I can push up on the drive shaft with a force of about one grunt and get the transmission to move around a little. Would that be considered normal? or bad...

I'm hoping its just a transmission mount. So I get to go under and replace every other mount which hasn't been touched for 15 years .

 

Sorry for being rude, bad day, but I should keep that my problem.

 

No worries. That's the way she goes on here... Idk, it was late...

So, you said the TC has some movement, idk if thats normal.. I've heard that the output shaft from TC to rear DS (where the boot is) can get, essentially, dry, and cause a dead spot that will clunk when coming to a complete stop?
Any garage worth their weight should be able to throw it on a lift and tell ya what's up (for free).. It could be the front DS. Thought my TC chain was going cause at first it would only sound like hell when in 4, but then it was clunking and vibrating when in 2. Maybe try removing the front DS? It 8, 13mm bolts (I think 13..) and done.
Idk, I'm outta ideas! Need coffee...

 

I'd say that is a sign of a bad tranny mount. But as suggested above, try removing the front driveshaft and taking it for a drive to see if that helps.

If not, do the tranny mount. And I'd also suggest doing the motor mounts at the same time, because if one or the other is worn out, it puts more stress on the other, causing it to wear faster

 

check the exhaust where it runs over the tranny crossmember, the mounts rust off and the exhaust rubs and hits the crossmember making all sorts of fun sounds

 

x2! I one day heard the weirdest squeak from somewhere. Thought it was new belt slipping. Turns out it was the heat shield from gas tank area rubbing on exhaust... Go figure...

 

Do you ever get any clunking when coming to a stop or putting in reverse?

I had nice audible clunk depending on the stress the driveline was under.

I greased the slip yoke (do a search) and made noticable difference. They need to be greased but I also need to change out my leafs to get to the root of the problem .