My 1979 Jeep CJ7 has been treating me well. I have had almost no issues. Then after locking the hubs after a bad snow I discovered that I had a bad u-joint in the drive shaft.
My brother helped me remove the drive shaft (which is a pain off of the quadratrac transfer case) , and after disassembling the driveshaft I discovered that the double-cardon joint had some issues. The main part is called a Center Yoke (or Link Yoke) and got chewed up pretty bad:

I found a place online selling a replace for around $90, and I’m going to do some more checking. I picked up some u-joints and the main ball-joint like part at my local NAPA. I have to say they were extremely helpful up there.
I did find someone who did a walk-through of a double-cardon rebuild for a ZJ:
http://www.mallcrawlin.com/forum/showthread.php?t=7478
I also picked up a complete window washer pump/reservoir at NAPA for a little under $40. My daily driver is becoming more and more complete.
