clunk noise

[turbolariat]

hi guys im new to the forum and new to diesels. i have a 00 f250 crew cab. heres the problem when i first pull out there is almost a hesitation and then a clunk, then while im drive i can let off and hear a clunk and right as i get back into it there is a clunk. now the throttle feels like there is some slop cause the peddle isnt as touchy as it once was. and it has been feelin slugish lately. please help and maybe give me an idea. thanks

[1999_f350_crew]

Is it an automatic or 6 speed?

[460+]

Check the ujoints on sounds like theres one out. If you run it hard I have seen pinion gears loosen up and make that noise.Probablly ujoints.

[TruckTrooper]

i had that problem and i had to replace the hub assembly bc the 4 wheel drive kept coming on

[turbolariat]

its an automatic and has about 150k on it. i have checked all the u joints and havent found one that need replaced. if my pinion gears are loose what do i need to do. i can get the rear drive shaft to spin about an 1/8 of a turn not much though. i thought maybe my trans but it almost seems like theres something loose. it so irritating that i cant figure this out.