Clunk while moving in reverse

[section525]

My buddy has a '96 4WD and he's getting this clunk while moving in reverse. It's not a clunk while putting it into reverse. It's a clunk after it's engaged and traveling backwards. It doesn't happen everytime. Only about 60% of the time.

We put new U-joints in the rear shaft. Didn't fix the problem.

We noticed some play in his rear shaft so we swapped it out with one I had in the garage. Didn't fix the problem.

It sounds like it's coming from the rear of the truck... behind the transfer case. So now I am thinking it's one of two things.

Either the brake caliper bolt(s) backed out like many Explorers do and it's binding against the wheel sometimes. Or, there's something wrong in the rear end. I think the calipers are the less likely of the two, but it would be nice if it was the problem.

So what do you guys think? We'll puff the diff cover this week and see what we see. This doesn't really sound like a tranny issue, right? It goes into gear, and changes throughout the gears fine.

 

[toypaseo]

The Explorer I bought from my parents had a similar noise. I also thought u-joints. I took it to a small local mechanic to get the rear ones replaced. He checked them out, said they were in perfect condition, and just greased the slip yoke, I think. Noise is gone.

 

[Hoppy]

Section525,

Did you find the problem and get a fix? I am getting the same noise from my 2000 explorer.

 

[97redsport]

Me too, I would like to here the prognosis of this issues. I have checked for loss calipers and nothing there, drive shaft has no play either.

 

[BigLumber]

Motor mounts? Dealer replace front drive shaft on our mountaineer. Started replacing all kinds of other things and never did eliminate the noise.
Nephew recommended checking the motor mounts.

Just a thought

 

[marragtop]

Assuming it's not AWD, jack the back up and put it in reverse to pinpoint where the noise is coming from. It should be either mounts, shaft, or axel.

 

[HappyGecko]

I am having this same problem, but when I have my wife jump in to duplicate the noise, she doesn't drive it aggressively like me, so the noise never happens.

Guess I will hunt down someone with a little more testosterone in their system, and see if they can't duplicate the noise.

I'll keep you posted when I figure out the problem.