Does anyone know why on the earlier 12v 4x4 5spd's there is what looks to be some kind of balancer near the t-case and on late (98 12v) there isn't one?

 

I don't know about the 4X4, but on the '94 there was a TSB that installed a large balancer to eliminate a vibration/drone under acceleration at higher speeds.
george

 

I dropped my driveshaft (the yoke with the balancer) when I had it apart for u-joints and the when I put it back together I had an awful vibration @ 110kph 60mph. It was so bad that I thought the outputshaft bearing had packed it in. I went to the wrecking yard and got a driveshaft out of a '98 and it was missing to balancer. So far the only difference I have noticed is when I lug the motor to 1000rpm then accelerate there is a drone. I can live with the drone but couldn't live with the vibration.

 

Russell,

All you need to do with your original driveshaft is get it balanced. Replacing your u-joints is enough to put it out of balance (unless it got bent when it was dropped).

 

The balancer fell off of my workbench and landed on the concrete floor which resulted in a 2" flat spot on one side.

 

Any updates on this? Every local shop tells me it is there for a reason and needs to stay/be replaced if falling off or damaged. The one in my truck is suspect and I don't see why a good balance job would not do the trick..