i have a 99 ram 1500 5.9L automatic everything was great with the truck, then the trans went, i replaced the trans with a trans from a donor truck with 60,000. my truck has 156,000. before i took the trans out of the other truck i ran the truck and everything was PERFECT with that trans and ever since that day (a month ago) i have a nasty driveline shake. it starts around 25mph and goes on. it doesnt shake the truck at all, its def in the driveline somewhere, like the transfer case or rear shaft. at higher speeds my 4 wheel drive shifter goes nuts. it ONLY shakes when i am on the throttle. the second i get off the throttle at any speed......its smooth as can be again. and if i put it into neutral at any speed and rev it up....its smooth. its only when the driveshaft is under torque. the truck is an extended cab reg box. and it is lifted roughly 4 inches and on 35's. But this problem i doubt is lift related bc it was fine for months lifted. ??? U joint maybe ???

 

Check your trans mount, mine did the sme thing after I lifted mine.

 

yeah....mine was shot....the rubber was all dryrotted....and falling apart....so i figured thats what was up with the vibrations.....so i changed it......guess what....didnt fix it...

 

damn dude that sucks, maybe an engine mount is loose?

 

thats something i could look into....but i think that would make #1 the whole truck vibrate....and #2 i think it would shake all the time....not just when im on the thrttle with torque on driveline.....bc if i am at a higher speed and i slip it into neutral and rev on it...its smooth.....but if im in gear and even breath on the throttle....it vibrates. the second i release throttle...its back to smooth again

 

true that.

 

sounds like your u-joints to me. you could ave not properly seated the u-oints back in. i have had the rear u-joint on the rear end go bad and git stiff and it caused the same problem. you should change them any way they are cheap and easy to do! i would start there.

 

I concur with jumper's suggestion. I had the same issue caused by u-joints.

 

Check the torque on every fastener that you took off.

 

126000 new tranny at 112000. AFter noticing the vibration I thought it was my exhaust leak. I put up with it for about 6 weeks and then on the highway it got way way worse. About 5 minutes after that my driveshaft fell out on the highway. The rear caps had busted off. I had the driveshaft rebuilt and reinstalled it. The driveshaft is still bolted in but the vibration is back and just as bad as it was for the 6 weeks. I guess it wasn't the driveshaft causing the problem but it was the result.I am scared. Reading some forums I found the problem could be maybe i installed the shaft 180 degrees wrong. Also maybe the guy who did the rebuilding messed it up but I doubt that. Advice - don't keep driving with that noise.