1990 K5 Vibration at Moderate Speed

[allamericanmale30]

What would be the likely cause of vibration at my intermediate to rear portion of my drive train at roughly 55 to 65 mph? I replaced the u-joints and noticed there is a small notch where the u-joints seats into the rear drive shaft, could that cause vibration?

 

[johnathan]

i have always had vibe issues with my k5.My advice would be t stick it in nuetral on flat ground p brake applied and grab the rear shaft. anyup-down side-side movement and somethin should be done.If its an auto tranny check the slip yoke.Any modifications been done to your rig ,lift,big tires etc.?and by the way my 84 k5 still has some vibes at high speed,just an old truck for ya

 

[allamericanmale30]

It's pretty much stock, I had to replace the rear-end about 3 months ago with one from a salvage yard. It looked good and was a match to the front. I have it all tore down trying to figure out what is going on.

 

[johnathan]

did it do that with the old rearend?

 

[allamericanmale30]

not at all, could it be caused by the u-joint housing piece having a chip in it?

 

[johnathan]

i have swaped a 14 bolt in mine it has a chunk missing like your talkin about, no problems though. does the u-joint seat tightly?

 

[allamericanmale30]

Yeah it seats in there tightly, think I can just rotate the rear drive shaft 180 would help?

 

[johnathan]

yeah could be outa phase.don't give up persistance pays off good luck man

 

[roadnotca]

Check/balance the drive shaft.(?)