Thud in driveline when taking off
 

Hey guys, I recently bought a 2005 24valve 4 door long bed 4x4 with 105K. I have noticed now that the weather is getting warmer that when the truck has been driven for a while it has a delayed thud that feels like it is in the rear end from take off. It does not do it when you first start driving usually after about 20 minutes of driving. If you feather the throttle from a stop light or if I have a trailer, you don't feel it. Under normal driving it has a thud feeling but no noise, when you take your foot of the brake and apply the throttle. It drives fine and has no other issues. Fluid in the rear looks good, no metal to speak of. The pinion and u joints all seem tight with no play. Changing gears in the driveway while watching underneath shows no signs of slack from a worn out rear end. The trans shifts good and the fluid in the trans is in great shape. It feels like a LSD that has to catch up when you take off from a stop. Any ideas or has anyone else run into a similar problem? Wondering if I need to rebuild the differential or look some where else for the problem. Thanks in advance for the help.

Ujoints maybe?

Sounds like your center bearing in your 2 piece driveshaft is wearing out. A lot of people here have changed out the 2 piece driveshaft and replaced it with a single shaft. My truck was doing the same thing, so I put a single shaft in mine and got rid of that weak carrier or center bearing, hasn't klunked since.