Drivetrain movement?

[Mike1]

97-PRESENT TJ FRONT CLIP

Hi

I have had 2 Jeep 4.0L auto Cherokee's. The first a 1996 and the second a 1998.
Both vehicles have an annoying characteristic when coming to a stop. After stopping and the taking your foot off the brake to accelerate there is a loud "thunk" as if someting is disengaging or re-engaging. The noise seems to be in the area of prop-shaft/transfer case/rear diff.
It could definitely related to "play" in one of these areas?
It also seems to be dependant on the severity of the breaking, after a hard stop the sound is worse. As I mentioned this has been the case with both vehicles different year models so it must be a common problem?
Has anyone had the same experience can anything be done, is anything being damaged by this.

regards Michael (SA) :?:

 

[graewulf]

what was the mileage, out of curiosity?

 

[Bounty__Hunter]

Sounds like a busted transmission mount and/or engine mounts. Check for a torque mount next to the transmission mount, it prevents this type of movement.

 

[Mike1]

Hi Graewulf

The mileage in both instances is around 100 000Miles, most of my driving is on the freeway.

Any suggestions?

Michael

 

[balloo93]

The 96 plus Command trac TC has a sealed slip yoke. This slip yoke is lubed from the fatory. If the lube is getting nasty or dried up it may be what is causing the thump. You can get some Silver anti-sieze, drop the DS and take the yoke out. Clean and lube the output shaft and put the yoke back on.

Beyond that, check the Ujoint at the slip yoke as well.

 

[Bounty__Hunter]

Check the transmission mount, and the front track bar. Track bar should be very tight.

Both would cause that noise. Let us know what you find.

 

[Mike1]

Thanks

Will let everyone know

Michael

 

[hatemaker22]

my 88 xj made the same noise but i found that it was actually comming from the the rear drum brakes, they were for some reason sticking in the "brake" position then about a second after i took my foot off the brakes, they slammed back. Since both of your jeeps are doing this then it probably isnt the same thing as mine. but to fix mine i had to buy a new brake block that mount on the rear end that distributes the fluid to both sides.

 

[southtj]

I may not know what I'm talking about here but...Many years ago I thought I was told that this was normal on some vehicles. As you are slowing down there is a phenomenom called "axle wrap" that occurs, I think on leaf springs. Anybody following me here? When the brake is released to accelerate, the tension is released causing a 'clunking' sound.

I think this happened on my 81 Bronco many moons ago and I know that my wife's Explorer does this on occasion.

Again, please reread my first sentance. :roll:

 

[balloo93]

I may not know what I'm talking about here but...Many years ago I thought I was told that this was normal on some vehicles. As you are slowing down there is a phenomenom called "axle wrap" that occurs, I think on leaf springs. Anybody following me here? When the brake is released to accelerate, the tension is released causing a 'clunking' sound.

I think this happened on my 81 Bronco many moons ago and I know that my wife's Explorer does this on occasion.

Again, please reread my first sentance. :roll:

Axle wrap is more common in high horse power applications, SOA conversions, and leafs with large lift blocks. A stock XJ should have no problem with axle wrap.

No harm no foul, axle wrap does happen, just not that often with stocker XJ's. Throw some 4" lift blocks on the same XJ, and you stand a good chance of having axle wrap.

 

[Mike1]

Hi

I had the grease replaced on the slip yoke, and what do you know the problem is gone. Also by the way the drive is allot smoother and no vibrations on freeway driving anymore.

Thanks for all the great advise.

Mike (SA) 8)