I have a 98 F150 the problem is when I come to a complete stop and then accelerate it feels like the springs are wrapping or something has alot of play in it. I laid under the truck and had my dad slowly give it gas while the parking brake was set looking for something that was moving but I couldnt find anything. I have went thru the rear suspension and retightned all the nuts and bolts that I could but it still does it. Has anyone else had this problem? Thanks

 

motor or transmission mounts?

when you give it gas does the engine move??

 

ditto! that was my first thought...

 

Are there any sounds and can you tell where they are coming from? Any vibrations or handling issues? Is the truck 2wd or 4wd?

If it was suspension related, you would probably hear and feel it more often than just at take off. It may also cause handling issues, too.

It could be motor/tranny mounts, but I would start more simple. Without knowing other than that you described, I'd start with checking the U-joints on your drive shaft(s).

 

I dont see any visible movement in the motor mounts but when i lay under the truck i can pick up the tranny about 1/4 inch but it doesnt look bad though. Its a 4x4 I dont have any handling or drivetrain problems. I also upgraded the u joints last year and I have checked them out last week and they are fine. If you put something in your bed that would be like a gas can or something and take off and it falls over and makes a thunking noise and a feeling in the body of the truck. Thats what it is. I dont hear it as much as i feel it.