Another whats that noise before I spend $$on a TC thread

1998 sport straight 6 auto.166k miles. just picked it up about 3 weeks ago and have been getting it in order to drive. It hasn't been beat on.It has a lift in it - about 3.5 inches of lift. Looks like its mostly stock other than that.Even still has the stock sized tires on it .
Know my way around jeeps somewhat as I've owned 3 other xjs - this is a new sound/feel to me.
It pulls strong with no issues - acceleration is fine and there are no clunks/grinds/slaps etc while under acceleration.
When decelerating from oh anywhere from maybe 30mph and up there is a noise that sounds like its almost under me - maybe a little back - thats kind of a horrible growl/grind kind of noise - you can feel it a bit . This is only when you let off the throttle . If you are at speed and sort of tap back on the throttle and off again it will make the same noise .
So almost always at deceleration - somewhere under me - acceleration does not cause it.
4wd works fine - makes the noise the same in 2wd and 4wd.
I am leaning towards transfer case issues but not 100% sure

sounds like a stretched t-case chain.....or could be rear D/S as it doesn't seem to have a SYE

does removing the front d/s make a difference ? in 2wd or 4wd ???

It could also be worn pinion or carrier bearings in the rear end. I've had that happen before on deceleration when the rear end was going out.



Try putting it on jack stands and have someone attempt to locate the noise as you accelerate and decelerate the drivetrain.

The u-joints should be your primary suspect.

A stretched T-Case chain would, when in 4x4 Low, make a popping sound and move around the whole T-Case at the same time. In 4x4 High and 2wd, a stretched chain would probably not make any noise, or only make a faint grinding noise.

Worn u-joints often make noise only on acceleration, or only on deceleration, or they make a wowww-wowww-wowww rhythmic noise at highway speeds. Severly worn out u-joints make nasty noises on decleration/coasting, yet are almost silent when driving the axle. U-joints are easy to diagnose and easy to replace.

Start with some diagnostics, remove the rear drive shaft and go for test drive in 4x4 High. If the rear driveline is the root cause of the sounds it should now be nearly silent. A simple inspection will rule in, or rule out, the u-joints and/or the pinion.

At 3.5 inches of lift the Cherokee really should have an SYE.

It sounds like "not" having a sye.

During decel, the chain will get slack in it, just like a motorcycle chain....under load, it is tight, under decel, it is not. On a motorcycle or bike, when moving, the top of the chain loop is tight, and the bottom is slack, but when decelerating, they both go slack.

In the t-case, when moving forward, the bottom of the chain is tight as it is under load...but upon decel, it is not under load, letting it get slack and it can rub the bottom of the case. In 4wd, you also have the risk of the chain slipping teeth if it is stretched bad enough.

Been there done that....not saying it is the problem here, but it is a possibility.

My guess is he needs a SYE more........


Won't you lose t-case fluid with no rear D/S in it ?? Been so long since I had a stock t-case output, don't remember if there's a seal or not to keep fluid in with no D/S.

TRCM said:

Won't you lose t-case fluid with no rear D/S in it ?? Been so long since I had a stock t-case output, don't remember if there's a seal or not to keep fluid in with no D/S.

Click to expand...

Up to 96 yes, but no on 97+.

gotcha.....mine have been 88 & 96

that's why I didn't suggest removing the rear D/S myself earlier.

Also just found out my 96 cherokee sport takes a 98 grand cherokee temp sensor.

Logged into comment on this. Its the drive-line angle of your rear driveshaft. I had the exact same problem/sound. I put a TC drop in and its been gone ever since.