Need some help...

For the first time ever im having problems with my truck and i have no idea what it is and ive talked to some tech's and they really didnt help. Anyway from about thirty to fifty five mph my truck starts to shake really bad. It also does it after that if i try to speed up fast(like when you start in the wrong gear except alot worse). i kinda think it might be my tranny but i a have no prblems with shifting so i dont know. If anyone has any ides what this is and how to fix it let me know.Thanks.

last time u did a tune up? brakes? balljoints? could be a number of things, prob jumped timing how many miles u got and what motor?

Its the v6 4.0 with 75,000 mi and i replaced the front balljoints when i lowerd it in june and got a tune up in july.

hey check your u bolts and your pinion angle, is possible they came loose which would make sense that you can shift fine and only feel vibration at certain speeds

Yea it was the u bolts i got them replaced today and shes back on the road, thanks alot man.By the way i had a friend bend a pipe for me for a new intake but what else am i ganna need?I know i need a new filter but what about the hose thats connected to the stock intake?How do i pt it on the new one?

the intake i have his a little nipple on it that you plug it on to. I used that blue hosing that comes with most intake kits and just stuck my sensor in one end and plugged the other end into the pipe.