I'm the new owner of a 2005 F350 4X4 6.0L PSD with 88k, and an automatic transmission. I notice a slight thunk when I first accelerate from a complete stop, and was wondering if this is a normal condition for this truck, or something I should be concerned about. It kind of feels like something engaging, but this is my first heavy duty truck, so I don't know. Any information would appreciated.

 

Sounds like u-joints maybe going bad. I would get that checked out. Try climbing under the truck and turning the drive shaft by hand to see if there is a lot of play in the u-joints.

 

https://www.ford-trucks.com/forums/1...ard-clunk.html

 

Thanks, that sounds like it might be it, I'll give it a try.