My 96 XJ (145K miles) produces strong clunk upon initial acceleration after
a moderately quick stop. The quicker the stop, the stronger the clunk. It
does not do this after normal conservative braking. The drive shaft
U-joints are nice and tight. Nothing appears to be loose or worn. I have
had the vehicle about a year. Any ideas what causes this type of flex? Is
it just normal behavior of leaf springs to wind up and unwind causing this
movement? Thanks.

 

The bushings in the leaf spring eyes can wear out and allow lateral
contact with the shackles. Also check that all bolts on your suspension
are tight.

Sounds like you are sure it is coming from the rear, but noises can
travel. Could be bad bushings/joints/ends or loose bolts in control arms
or steering components. Even worn hinge pins on a door can cause clunks
that seem to come from below.

Steve
http://xjeep.dyndns.org

rgarrett wrote:
> My 96 XJ (145K miles) produces strong clunk upon initial acceleration after
> a moderately quick stop. The quicker the stop, the stronger the clunk. It
> does not do this after normal conservative braking. The drive shaft
> U-joints are nice and tight. Nothing appears to be loose or worn. I have
> had the vehicle about a year. Any ideas what causes this type of flex? Is
> it just normal behavior of leaf springs to wind up and unwind causing this
> movement? Thanks.

 

The bushings in the leaf spring eyes can wear out and allow lateral
contact with the shackles. Also check that all bolts on your suspension
are tight.

Sounds like you are sure it is coming from the rear, but noises can
travel. Could be bad bushings/joints/ends or loose bolts in control arms
or steering components. Even worn hinge pins on a door can cause clunks
that seem to come from below.

Steve
http://xjeep.dyndns.org

rgarrett wrote:
> My 96 XJ (145K miles) produces strong clunk upon initial acceleration after
> a moderately quick stop. The quicker the stop, the stronger the clunk. It
> does not do this after normal conservative braking. The drive shaft
> U-joints are nice and tight. Nothing appears to be loose or worn. I have
> had the vehicle about a year. Any ideas what causes this type of flex? Is
> it just normal behavior of leaf springs to wind up and unwind causing this
> movement? Thanks.

 

The bushings in the leaf spring eyes can wear out and allow lateral
contact with the shackles. Also check that all bolts on your suspension
are tight.

Sounds like you are sure it is coming from the rear, but noises can
travel. Could be bad bushings/joints/ends or loose bolts in control arms
or steering components. Even worn hinge pins on a door can cause clunks
that seem to come from below.

Steve
http://xjeep.dyndns.org

rgarrett wrote:
> My 96 XJ (145K miles) produces strong clunk upon initial acceleration after
> a moderately quick stop. The quicker the stop, the stronger the clunk. It
> does not do this after normal conservative braking. The drive shaft
> U-joints are nice and tight. Nothing appears to be loose or worn. I have
> had the vehicle about a year. Any ideas what causes this type of flex? Is
> it just normal behavior of leaf springs to wind up and unwind causing this
> movement? Thanks.

 

Besides the spring bushings, you likely have a slip joint in the rear
axle that will cause a clunk when it needs grease.

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!
Aug./05 http://www.imagestation.com/album/in...?id=2120343242
(More Off Road album links at bottom of the view page)

rgarrett wrote:
>
> My 96 XJ (145K miles) produces strong clunk upon initial acceleration after
> a moderately quick stop. The quicker the stop, the stronger the clunk. It
> does not do this after normal conservative braking. The drive shaft
> U-joints are nice and tight. Nothing appears to be loose or worn. I have
> had the vehicle about a year. Any ideas what causes this type of flex? Is
> it just normal behavior of leaf springs to wind up and unwind causing this
> movement? Thanks.

 

Besides the spring bushings, you likely have a slip joint in the rear
axle that will cause a clunk when it needs grease.

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!
Aug./05 http://www.imagestation.com/album/in...?id=2120343242
(More Off Road album links at bottom of the view page)

rgarrett wrote:
>
> My 96 XJ (145K miles) produces strong clunk upon initial acceleration after
> a moderately quick stop. The quicker the stop, the stronger the clunk. It
> does not do this after normal conservative braking. The drive shaft
> U-joints are nice and tight. Nothing appears to be loose or worn. I have
> had the vehicle about a year. Any ideas what causes this type of flex? Is
> it just normal behavior of leaf springs to wind up and unwind causing this
> movement? Thanks.

 

Besides the spring bushings, you likely have a slip joint in the rear
axle that will cause a clunk when it needs grease.

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!
Aug./05 http://www.imagestation.com/album/in...?id=2120343242
(More Off Road album links at bottom of the view page)

rgarrett wrote:
>
> My 96 XJ (145K miles) produces strong clunk upon initial acceleration after
> a moderately quick stop. The quicker the stop, the stronger the clunk. It
> does not do this after normal conservative braking. The drive shaft
> U-joints are nice and tight. Nothing appears to be loose or worn. I have
> had the vehicle about a year. Any ideas what causes this type of flex? Is
> it just normal behavior of leaf springs to wind up and unwind causing this
> movement? Thanks.

 

"Mike Romain" <romainm@sympatico.ca> wrote in message
news:436A541A.7DA24DDD@sympatico.ca...
> Besides the spring bushings, you likely have a slip joint in the rear
> axle that will cause a clunk when it needs grease.
>
Mike is right as usual. Starting around 96 they changed the output of the
transfer case going to the rear axel. I had the noise on a 96 with 140k
miles and it's 99 xj replacement with 90k miles on it. It's a easy fix just
drop the rear of the shaft and slide it out of the transfer case. A little
dexron may come out of the transfer case so put a pan or whatever under it.
Once off clean the spline and coat it evenly with NEVER SEIZE. I did the 96
over a year ago and the noise is still gone. Make sure to use lock-tite on
the clamp nuts on the rear diff.

JoBo

 

"Mike Romain" <romainm@sympatico.ca> wrote in message
news:436A541A.7DA24DDD@sympatico.ca...
> Besides the spring bushings, you likely have a slip joint in the rear
> axle that will cause a clunk when it needs grease.
>
Mike is right as usual. Starting around 96 they changed the output of the
transfer case going to the rear axel. I had the noise on a 96 with 140k
miles and it's 99 xj replacement with 90k miles on it. It's a easy fix just
drop the rear of the shaft and slide it out of the transfer case. A little
dexron may come out of the transfer case so put a pan or whatever under it.
Once off clean the spline and coat it evenly with NEVER SEIZE. I did the 96
over a year ago and the noise is still gone. Make sure to use lock-tite on
the clamp nuts on the rear diff.

JoBo

 

"Mike Romain" <romainm@sympatico.ca> wrote in message
news:436A541A.7DA24DDD@sympatico.ca...
> Besides the spring bushings, you likely have a slip joint in the rear
> axle that will cause a clunk when it needs grease.
>
Mike is right as usual. Starting around 96 they changed the output of the
transfer case going to the rear axel. I had the noise on a 96 with 140k
miles and it's 99 xj replacement with 90k miles on it. It's a easy fix just
drop the rear of the shaft and slide it out of the transfer case. A little
dexron may come out of the transfer case so put a pan or whatever under it.
Once off clean the spline and coat it evenly with NEVER SEIZE. I did the 96
over a year ago and the noise is still gone. Make sure to use lock-tite on
the clamp nuts on the rear diff.

JoBo