Vibration Problem

[autobodyman2]

for some background info, I have an 82 chevy k 30 dump. It has the 14 bolt rear. I had to replace the tranny and ever since then, i have a bad vibration from about 25-45 and quits after that. It will also stop if I push the clutch in. I believe it to be coming from the rear end. How true is it that the driveshaft has to be marked before you pull it back out? I have had it out and in a bunch of times, and maybe i screwed up there, any help is appreciated.

[Palf70Step]

I am thinking your carrier bearing for the drive shaft. I have only been involved in replacing one and I'm not a whole lot of help on the procedures cause I was mostly the gopher so my friend would not have to climb from under the truck while changing it for me.

[old Rusty C10]

i agree the carrier bearing but it could also be the driveshaft.. also is it possible the u joints were damaged in any way when you took it out
i find it very hard tio think its the rear end if it only started after the trans was done...