clunk after letting off the gas from a hard acceleration

yankeejeeper02

yankeejeeper02

New Member
Joined
Apr 29, 2007
Location
Raleigh
I have been chasing a metal sounding clunk after letting off the gas from a hard acceleration, and also when shifting from drive to reverse. Its def not the u-joints!

I found this online and wonder if this could be the cause, also how would I check to see if it is the cause?

"With Fords limited slip axle, clutches are used. As they wear, the end play between the axle and spider gear increases. Mine increased to the point of actually causing the brake shoes to split down the center lengthwise, and warped the drivers side drum. I obtained a new spring, clutch and steel pack from West Coast Differential for around $100.00. Everything can be changed with the carrier in the truck. The clutches increased from three to four per side. Traction is greatly improved, and the noise is gone."
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What vehicle do you have? I don't really see how this would split brake shoes, especially considering the shoes are stationary.

It could be wheel bearings, spline wear, spider gear wear, excessive R&P backlash due to wear, U joint wear, t-case wear, transmission wear, etc.

My wife's 95 ZJ does it, my mom's 04 WJ does it, and my 04 Passat does it.

The reason is much like a hammer. If you place the head of the hammer 1/4" off a nail, and hit it, you can't get much impact. If you hold it 6" off the nail, you can get enough impact to drive it in. The same is true with driveline lash. Generally, the only lash should be in the ring&pinion gears. But time and torque have there effects, and causes lash in all the other places I mentioned. Brand new vehicles probably only have about 1 degree of rotational lash, but as things wear, that number increases drastically. I would guess my jeep has 10-15 degrees of rotation on the driveline, because of worn out parts. Hope that helps.
 
Open up the diff and look. I bet you'll find some sort of damage. I was driving my ZJ with 33s on the road and suddenly started hearing metal on metal clunking noise when I would let off the gas. The side gears and spider gears were chewed up on the edges of the gears.
ai303.photobucket.com_albums_nn152_VortecJeep_ZJ_ZJspidergears2.jpg
 
My 8.8 was doing the same thing until I rebuilt the LSD with new cltuchs. The spider gears were moving in the carrier due to being worn out. Replaced with 1 extra clutch on each side, and is alot better now.:driver:
 
devlsh1 said:
My 8.8 was doing the same thing until I rebuilt the LSD with new cltuchs. The spider gears were moving in the carrier due to being worn out. Replaced with 1 extra clutch on each side, and is alot better now.:driver:
Click to expand...


Any recommendation on where to pick up a clutch set? How hard was it too add an extra clutch on each side?

Thanks
 
A buddy of mine had a similar issue a few weeks ago on a TJ. It turned out the rear pinion nut had backed off. when you accelerate the pinion gear angle would drive itself out toward the tranny and would run closeto correct position. When you let off the power the pinion sinks back into the diff and there was an audible clunk. It would clunk in reverse cuz the pinion was driven inward toward the diff. It would grind occaisionally too.
 
Cperry at Eastern Gear supply told me $80 shipped, I got mine off E-bay for $60. The ones I got the steels wouldnt fit, so I had to use original ones with new clutches. When I pulled the clutchs out it went steel, clutch, steel, steel, clutch, steel, clutch. So I swapped out where there was 2 steels, I changed out 1 steel with 1 more clutch plate. It did make it a tight fit to put back together, it took me about 2 hrs to get it back together. The only other one I have messsed with was on my Dana 35, and that was a disaster (probably another reason I have an 8.8 installed now). Just document how it comes apart, and put shims and everything else back together the same side and same way. Pics work well for me.
 
Definitely check with CPerry. I've ordered parts from him (including the side gears and spider gears). Nice guy and if you have any questions, he'll tell you what you need to know.
 
devlsh1 said:
My 8.8 was doing the same thing until I rebuilt the LSD with new cltuchs. The spider gears were moving in the carrier due to being worn out. Replaced with 1 extra clutch on each side, and is alot better now.:driver:
Click to expand...
I had a ford 7.5 that was doing the same. loud clank when you hit the gas hard, and let off the gas from accelerating. As long as there was tourqe on the rear, it was quite. it was the cross-pin that was broken into three pcs. the screw that holds it in place was still there.
I had several different shops, including ford dealerships tell me it was several different things. I didn't find it until the rear locked up and left me sitting on the side of the road. i would seriously consider pulling the cover and looking in before ordering parts.
 
Its not a daily driver so i'm going to start taking it apart bit by bit to track it down. I would hate to tear into the gears if its just something stupid.

I know its def not the gears as they looked great when the rear was put in less than 150 miles ago. I cannot hear it from the pass side only the drivers. I wonder if it is possible for brake shoes over tightened to make this sound. The lug nuts are tight. Sorry just thinking out loud.
 
Its spider gears I just ate mine up in mtn city last week!!!!! check control arms as well! if its spiders just weld it up mines running fine on road locked in the rear!
 
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