What would cause the truck to shake after upshift?

I fired her up and went for a drive, worked as a charm when i accelerated. I eased on the throttle and it shifted up. When i just let it roll in idle there was no problems but then when i started accelerating the truck shakes if i accelerate in a regular manner. It goes away if i floor it and it shifts down.

Any ideas? I checked the fluid level in the transmission and its like waaaay too much. Could this be the problem?

 

Yes. I had the same problem. Drain all transmission fluid out (also out of the torque converter) change the filter and refill your tranny. Now add shutter gaurd. I added 2 tubes of it. ive heard that lucas trans additive works just as good. That should clear it up for you. It did mine. It seemed to only do it when it got cold. The summer time it worked fine. it was weird. But now it works great all the time.

NEEDED
Transmission filter
new fluid
shutter gaurd. (it comes in a red tube)

Hope this helps

 

Mine used to do that so I changed the tranny fluid and changed the filter. I did not add any shutter guard though. Have not had any other problems since. Good luck.