I have an old beat up 89' pioneer and I have been replacing everything on it. After correcting my dead front hub assembly, I have noticed a wicked vibration at 25 MPH. I have checked all u-joints and I believe that I need to replace the rear from my transmission to the drive shaft. Does that sound like the right diagnosis and solution? I have a 4" lift with out the addition of a SYE. I do have shims under the leafs.

 

You have driveline vibes.. If the ujoints are bad you could replace them and see if that eliminates them. If that doesn't you need an SYE and for shortterm t-case drop.

 

grease your ds and see if that helps a little.

 

I replaced the u-joints and all is good.....for now anyway. When I fix one thing something else comes up, and I wouldn't trade it for anything! Thanks for the replies.