I have a 2001 F350 w/7.3L AOD. When I am first taking off from a stop, I feel a thud. Do not feel it w/trailer. Any ideas on what to check. Hoping its something other that the trans.

 

Slip yoke on the driveshaft, u-joints?

 

Elder user, thank you for the info, i will check it out. Hope its something easy/inexpensive as this. thank again

 

I'm curious if you found the problem? I think I have the same thing happening to mine.
chazmckay(No Email Addresses In Posts!)

 

You might try pulling driveline and applying grease to splines inside yoke, re-installing and see what happens, Ford had a t.s.b. out on this a few years ago, sounds like same symptom.
Ford used a special grease for t.s.b. but cannot remember what it is. Contact any Ford dealership and ask the diesel tech!!

 

Thanks, I will check w/Ford on the grease.