Drive line vibration

[Sojourner]

Great that the problem is GONE!

BTW...the difference between out-of-balance drive shaft and the unequal knuckle/yoke timing while on road is:
1)   Out-of-balance drive shaft will always vibrate from mid speed or higher every time with load or no load accelerating.
2)   Unequal knuckle/yoke timing will only vibrate under load while accelerating or climbing hill. Unequal u-joints phase (timing) will cause pulse turning vibration.

So you can know whether it #1 or #2 problem. No guessing game.

Another BTW...always checks U-joint before a long trip or chassis lube time for wear.
1)   A good joint is when you can manually (via hands) move to check for some end play.
2)   A bad joint is when you cannot move for end play and show red rust dust between spider web to bearing cap. And after driven more miles, it will give a "clink" or "snap" sound while shifting from forward to reverse in stand still with brakes applied. Hopefully you don't wait till it falls off while on the busy road.

FWIW

Sojourn for Christ, Gerald

PS...Thanks boogiethecat for posting that link for the inquiring bus nuts mind.

[HB of CJ]

No rocket science here.  Really.  We used to straighten drive shafts like straightening a gun barrel and then we used wheel weights held on with multiple radiator hose clamps.

We used pillow blocks and homemade indicators that showed out-of-round.  Could get it quite close, but could not quite get it perfect.  It seemed to work for us.

Drove along at normal speed (sometimes more than normal speed) and checked/felt for vibration.  Then we rotated the wheel weights a quarter turn and tried again.  Then an eighth turn.

When we felt/discovered a sweet spot, that was where we left stuff.  You should have seen our driveshaft jobs.  He he he.  Looked strange, but what the heck...it worked. 

Also found out that angularity was important.  The driveline had to be in sweet alignment with the U-joints in phase.  Worked wonders.  Lots of beer employeed.