gaedbo

This appears to me to be a dampner, balancer that is mounted to the Yoke. It looks like there was grease inside of it that has been thrown out from this Slip Yoke, and not from the Universal Joints, what do you think ?
According to the parts picture I looked at from a GM website, Part #26039762 comes as a one piece unit, and has been discontinued.
If I am able to find one, do you think replacing it will affect the driveshaft balancing. I say this because of how your supposed to mark the position of the driveshaft and yokes before removal, but this will be a new part without reference to the correct orientation.
I am thinking of replacing the Shaft Slip Yoke, Front and Rear Universal Joints, and the Rear Output Seal in the Transmission.
Any input would be appreciated, don't hold back if what I described is incorrect.

I just contacted my GM dealership and they said no dealership in the U.S. has this part. #26039762 Now what, google, ebay ?

OK, I got it fixed! I contacted multiple GM dealerships and asked them what their shop would do in this situation. They gave me the names of businesses that they use in similar issues. I chose one of them called Proven Force in Maple Grove, MN.
They explained that the dampner/balancer does not have lube in it, but recommended removing it. They said it is mounted with hard rubber which over time will harden and crack, and possibly seperate from the yoke and cause some serious problems.(Mine wasn't looking the best when we looked at it on their bench) They said the lube all over the underside of the car was from the Transmission Input Seal leaking. To prove it wasn't the yoke, they put liquid inside the yoke and pressurized it and there wasn't any leakage.
So they took my driveshaft, removed the dampner/balancer, removed the original driveshaft weights, put in new universal joints (Front & Rear), rebalanced the driveshaft, and painted it. I put in a new Transmission Input Seal, plus I also did the Rear End Pinion Seal while I had things apart.

Should be good to go now. I won't be able to drive it until April 1st to verify everything, but if there is a problem, I wil respond.

Got a chance to drive it sooner than I thought, on March 27th - Good News, no leaks from Input Seal, or Pinion Seal. Car runs smooth without driveshaft vibration. I am glad I did this. Now Iv'e been cleaning and painting under the car.