I have a 1997 ram 1500 extended cab, short bed with a 5.9 auto with 217K miles. The rear end has been rebuilt once, transfer replaced twice, and u-joints are relatively new.

The clunking I hear (it kind of sounds like the driveshaft is bouncing back and forth) is only when I'm in first gear, almost coasting. There is a very large clunk when the trans shifts into second (and can feel the clunk in the for boards). When accelerating (light or heavy) or breaking, no sounds or vibration felt.

After searching this forum, I found a few postings that were very similar, but none offered a suggestion other then "check the u-joints." My u-joints are fine. I did notice that when the rear end was freshly rebuilt, I did not notice the noise, but not positive that could be the issue. The clunking continued after new trans and u-joints.

I've read somewhere that the corporate 9.25" diff had some problems with the crush bearing collapsing allowing the pinion to slide in and out over time. I don't drive the truck radically. Normal acceleration, almost never breaking the tires loose.

Anyone else had this issue/symptoms? Any suggestions?

Thanks!