I just took my 93 w 350 auto on a 4 hr drive, on the way back at stops I would take off and I heard a popping noise and had a jerky take off but it would clear up after i got up to bout 15 mph. But now on short trips it doesnt do it, only when driven for awhile.

what the heck is this?

 

Continuous popping/jerking until you got up to speed or one pop accompanied by a jerk when you started moving?

 

Block the front of the truck so it won't roll and jack the rear of the truck up and put the trans in neutral and spin things over by hand and watch and listen.
I bet a U-joint is acting up either really tight or just plain worn out.

 

Did you have your front hubs locked in? I agree with JD730-raise the truck up and start checking the drivelines. Be sure to check the u-joints in the front end that drives the front tires. When mine were locked in they would make all kinds of popping binding type noises. Good luck on your search.

 

Doing a four hour drive.. I hope your front hubs were not locked in. Any vibration? Check your u joints....

 

The hubs werent locked on the drive and I just put new U joints in the rear.

It will jerk maybe once or twice then quit once i get goin.

I dont have the front drive shaft in but my front yoke is turning even though my hubs arent locked, is it possible on my hubs "locked" means free and "free" means locked?????

 

They shouldn't be but stranger things have happened. Try crawling under there and turn your yoke by hand, if it spins freely your just getting a little backfeed from thick grease or it being a little tight ect. But if it won't turn at all lock the hubs and repeat the above. If it won't turn then you have internal problems in your front hubs. If you have problems go back and find BC847 thread from a while back-very good info-very well explained-and good pics. Good luck with it.