here is some information I found on which direction the zerk should be facing. Iam confused!
Back when I was drag racing, a drive line shop showed me how to install the joints. Hold a u-joint with the grease fitting at 1:30 and the caps at 12, 3, 6, and 9. You would put the transmission yoke at 12 and 6, and the driveshaft at 3 and 9. With the grease fitting at 1:30, the transmission is pushing towards 3 and nine, compressing the web with the fitting.
I assume the zirc is at the side, off center at the "x" of the joint. Rotate the joint to were you would try to grease it, and imagine zirc opposite direction of were it is pointing. Would that make room to grease? I am thinking the zirc should always
point away from driveshaft.
A u-joint should be installed with the grease fitting on the compression side of the yoke. What that means is, as the transmission yoke turns, it pushes on the grease fitting as it tries to turn the driveshaft. You don't want the yoke to pull on the webbing of the u-joint where the fitting is. The other end of the driveshaft is the same only the driveshaft yoke pushes on the fitting as it tries to turn the pinion yoke. The grease fitting should be pointing at the yoke with the most clearance, usually the driveshaft.
face the zerk on the rear drive shaft u-joint towards the t-case and the front joint on the rear drive shaft towards the rear axle. (so face them in).
this way you can get to them with a grease gun.