prop(drive) shaft "bump"

my truck has that notorious "bump" or thud after accelerating from a stop, ive heard it is something to do with the prop shaft, and there is a TSB to fix it, its never been that much of an issue to me..unless the ac is on. ive noticed if i go in to neutral when coming to a stop and shifting in to drive it doesnt do it. does the tsb fix eliminate this? its gotta be stored energy from the shaft coming to a stop then re engaging the rear end.

 

pull the slip yoke out of the ass end of the trans, put some good grease inside the female end of the slip yoke, should help.

 

i noticed upon examination the u joint and mount bolts to frame, shaft passes through looks fairly new, the steel is nice and shiny, leads me to believe it was serviced with the previous owner..odd that it still "bumps" is the problem lubrication( or lack therof) related then?

 

yes.

The prerunners have no slip joint on the rear half of the shaft. To account for the need for the driveshaft to extend and contract the shaft actually slips in and out of the rear of the transmission. This is where that bump comes from as it binds up untill there is enough pressure to make it slip at that joint. Put a bunch o grease on the bitch and it will solve your issue for a bit of time.

Very similar issues occur on most chevy full size trucks... i learned to live with it on mine as greasing the slip yoke every 10k was a pain.