vibration

[humblesouljah]

my truck vibrates in fifth gear when I hit around 3k rpms and up, this is the only time it vibrates. it has blocks on it from the previous owner.
I check pretty much everything and nothing seems to be loose.
Does anyone have an idea of what may be causing the vibration.
thanks
Bobby

[TRunner]

Is it lifted??? what kind of vibration are you talking about??? Mine has 5-6" of lift and I can feel Driveline vibs in 5th above 3k also. that is the fastest the driveline rotates and the otherwise small vibrations are more noticable at the higher velocity. the fix is to get a CV joint at the output of the transfer(in place of the current U-joint) and shim the pinion toward the output (I have already angled my pinion and the vibration is still there, I still need the CV joint though).