[Hulkjr]

Just installed a 2" lift on my '93 sierra, new springs and struts all round, and am now having issues with vibrations and Knocking from the uni joints on the drive shaft.

Pretty sure most of the vibration can be taken care of with a wheel and caster adjustment but was wondering how others when about fixing their drive shaft angle?

Was looking at lowering the transfer case but seems to be a fair bit of work involved in that.

And tips or sugestions appreciated

[greavesyzook]

I never had this issue with mine

[Gwagensteve]

I find the opposite- raising the transfer improves jackshaft angle which is the shaft that spins the fastest, and is the shortest, causing the most vibration.

[Eddy]

Check the condition of the uni joints first. 2 " lift is not going to cause any issues with driveshafts.

[pete_79]

Just wondering how common it is to get tailshaft vibrations after adding lift?

I can see the logic in lowering the transfer case, though my first thought would be to check the transfer and diff flanges are still parallel after the lift.

Then my next question is how common is the use of wedges to rest diff flange angle?

[MrRocky]

You use to get wedges and tailshaft spacers with the calmini 5" kit 10+ yrs ago but unless you have 3 - 4" lift springs there not really needed.
Ive found lifting the transfer can remove jackshaft vibes and extend uni life but as i mentioned it seems like more of an issue in lifted lwbs than swb versions