Needing a little help, Im no expert on working on vehicles but I have the know how but not the experience. Transsmission is a 3 speed with overdrive 5.0 302 V8. For the past two or so weeks my truck has been running really weak, engine is running fine and fluids are great but when ever i accelerate it feels as if its weak. And when i get to higher speeds around 45 or 50 there seems to be a bumping feeling, almost like hitting somthing in the road. its not very violent but its very noticable. Sometimes it wont do it the whole time i drive the truck but other times it will do it often. Seems to shake the truck and i have been told that you can tell the truck shutters when you are behind me. No strange noises or high revs from the engine and the U joints are fine and the drive shafts arnt loose. And the last time i checked (bout 4 months ago) there was a good amount of dope in the rear axle chunk. Happens alot when the truck is in overdrive and I start up a incline, doesnt want to shift out of overdrive as fast as i would expect.

 

3 speed + overdrive makes it a 4-speed automatic transmission. There were two available in this vintage truck. The mechanical/hydraulic AOD and the electronic controlled E4OD. The troubleshooting path is completely different between the two.

Check the B-pillar (door jamb) stick on the driver side. Look for the Transmission Code.
Trans Code T is the AOD. Trans Code E is an E4OD. More than likely you have an AOD, but we all need to know for sure.

 

No, the troubleshooting is the same for either. The problem is in the engine ignition. You have a bad coil, bad plug wires, or bad spark plugs. Possibly all three.

 

Its a T and yes its a auto, wasnt sure on wether it would be considered a 3 speed + overdrive or 4 speed

 

I did research on all them and they all seem close to the issues im having, almost exact but one thing id like to mention is i do feel lose of power when acclerating but the engine is running as if its fine but i dont feel the power, Not like i am used to.
I havent had anysurging or suddenly have it cut off but i have noticed when starting to accelerate the truck almost shuts off completely