hey guys im wondering if you might be able to help me with a issue ive been having.

i had to get a new driveshaft on the front because my CV joint froze up and snapped on it, so i got a replacement in june 2015 and when i put it on ive had a vibration when id do about 85-90mph. then in november my mechanic had told me thiers something wrong with the ujoint at the front differential. i took it to the place i got the driveshaft at and it was just the wrong ujoint on it. so they installed the right one. now when i hit about 75mph it vibrates, then the other day it happened about 65mph. so i crawled under their and moved it and the ujoints are good, only thing i see is the 2straps were tight on the front yoke but the ujoint was moving back and fourth just a little bit. but i then removed the shaft and 80% of my vibrations went away. i took it back to the place and they checked the balance on it and it was good. so i left it off. now the other vibrations is most likely tires vibration but its not bad. i have 35s. so i hit 100mph on the highway to just check things out and i had not unusual vibrations at all. what else can i look at to check for problems causing these vibrations? i want to say its the shaft cause like i said i took it out and now i have no issues.

 

You said you could move the u-joint while it was still bolted to the truck?

Perhaps when the cv axle failed/seized, it tranfered all of that kinetic energy to the differential, possibly damaging either the yoke or some other front end component.

Try to get a second opinion from a reputable driveline shop.