Clunking when decelerating

[Chad58]

I’ve changed both rear ujoints and noise is still there. What is under that boot on my rear driveshaft . When I was putting it back in I noticed some slip there...is that normal?

 

[dacaur2]

yes, thats a slip joint, its there to allow slight changes in driveshaft length.

 

[Chad58]

yes, thats a slip joint, its there to allow slight changes in driveshaft length.

Ok thanks. So it should slip back and forth, but should it havave any up and down play? Is it greaseable?

 

[Rcflyer330]

Is it a single clunk or multiple? soft or harsh? Does it sound metal to metal? When braking or not?
A better description of the noise will help narrow it down from anything that moves on the car to maybe a few parts it could be.

 

[kydirtscooter]

Does it happen at the same speeds with the same deceleration? I am wondering if you are feeling it downshifting. What happens if you downshift into 2 manual and leave it there? Does that clunk go away?

 

[Chad58]

Is it a single clunk or multiple? soft or harsh? Does it sound metal to metal? When braking or not?
A better description of the noise will help narrow it down from anything that moves on the car to maybe a few parts it could be.

It’s def multiple. As soon as you let off gas, some kind of rotational clunking is the best way to describe. It’s way more noticeable at slower speeds , mostly because road noise is less I guess. No weird shifts , no slips. As soon as you get back on gas it goes away.

 

[Chad58]

Does it happen at the same speeds with the same deceleration? I am wondering if you are feeling it downshifting. What happens if you downshift into 2 manual and leave it there? Does that clunk go away?

It happens at all speeds as soon as you let out of the gas. Manual didn’t help. Shifted into neutral and that didn’t help either.

 

[Explorer_PL]

Check the bushings on the rear diff holding it to the frame. See if you can move the rear pumpkin up and down.

 

[Chad58]

Turns out my rear diff is toast. Gonna have to replace or rebuild. How do I know if my abs sensor is internal or external?

 

[Rcflyer330]

The abs sensors are all external they are out by the wheels not in the differental.

 

[kydirtscooter]

I believe all 06+ had Advancetrac so you do not have an internal abs tone ring. But,

Look at the top of the differential, way up at the top drivers side. All the housings came with the hole but advancetrac had a small black plug instead of VSS. If you have a plug you do NOT have a tone ring in the diff. If you have an electrical plug then you do.

Or, look at the rear axleshafts at the wheel hub. If you have tone rings and pickup sensors on both sides then you do NOT have a tone ring in the diff. The tone rings on the axleshafts are pretty obvious.

As far as differential being shot, did the spider gears break or is the ring gear missing chunks?

 

[kydirtscooter]

Wrong post.

 

[Chad58]

I believe all 06+ had Advancetrac so you do not have an internal abs tone ring. But,

Look at the top of the differential, way up at the top drivers side. All the housings came with the hole but advancetrac had a small black plug instead of VSS. If you have a plug you do NOT have a tone ring in the diff. If you have an electrical plug then you do.

Or, look at the rear axleshafts at the wheel hub. If you have tone rings and pickup sensors on both sides then you do NOT have a tone ring in the diff. The tone rings on the axleshafts are pretty obvious.

As far as differential being shot, did the spider gears break or is the ring gear missing chunks?

I believe all 06+ had Advancetrac so you do not have an internal abs tone ring. But,

Look at the top of the differential, way up at the top drivers side. All the housings came with the hole but advancetrac had a small black plug instead of VSS. If you have a plug you do NOT have a tone ring in the diff. If you have an electrical plug then you do.

Or, look at the rear axleshafts at the wheel hub. If you have tone rings and pickup sensors on both sides then you do NOT have a tone ring in the diff. The tone rings on the axleshafts are pretty obvious.

As far as differential being shot, did the spider gears break or is the ring gear missing chunks?

Not sure , but you can put your hand on the hog head w it up on lift and feel the havoc going on inside when it’s in gear . I’ve never rebuilt one so I found a used one at my local salvage w a 30 day warranty for $249.