2003 F250 clunking noise on decel

[jsge090]

2003 F250 - I have a clunking noise when I get down to 15 mph or so. It only happens when slowing down. Has anyone had this issue? Could it be a U-joint?
Truck has 73k miles on it.
Thanks!
John

[pacific pete]

Had this problem with a Dodge Dakota a few years ago. Turned out it was backlash in the rear end gears. I had to remove the cover on the differential , and reset the backlash on the gears, by changing to different shims.
I am no expert but U Joints usually start to" snap" and make noises,,on take off from a dead stop. Roll the windows down ,and turn off the fan and radio, and listen for a snpping cracking noise on take off. If you hear noise then look at the U joints. If you can start from a dead stop, on a hill it will tell you soon enough, as the U joints are under load then
Hope this helps. Pacific Pete andthe crew.

[chipperhead]

Have to agree with "PP". With that said, (respectfully) what they usually do and what they do now can be two different things. If this were my truck I would chock it, slide down below and try to twist the drive shaft by hand. Any play at all is a bad U joint. However, just because we can't feel any play does not totally eliminate that problem. Sometimes they get noisy before they become "feely". U joints are relatively cheap and easy to replace. I, personally would replace the U's before I opened up the rear end.
Bye now,
Marty

[BroncoJoe19]

I doubt it is the U joint. If it is bad enough to clunk, it would vibrate like hell, when under load.

One possibility is a worn or broken exhaust bracket allowing the muffer (or exhaust) to hit something.

[jsge090]

Thanks All for getting back to me. I'll crawl under and check for play.

[BroncoJoe19]

Come to think of it I have heard of this with bronco's, I believe the solution was to grease up the tail shaft of the transfercase.

[Cuda_Jim]

4x4??
Is it a 2 piece rear drive shaft with a slip joint in the rear shaft?? (Rubber boot)
The slip joint may be dry.