I have seen some who also put oil into the ball housing/universal joint filler plug hole. Manual says this isn't necessary because that joint gets its lubrication from the transmission. Does it help to put a few ounces in the universal joint filler hole?
If you look at Page 4-10 of the service manual (the rear axle section), it says to put 1/2 pint of transmission lubricant thru the hole at the rear of the transmission. It says nothing about lubricating the u-joint in the transmission and u-joint sections.
