Jeep: XJ U-joint lube

Just had to replace the front axle U-joints on my 96
Cherokee at a cost of $450. About 124K miles showing.
Mostly road driving and regularly oil-changed and
lubed at a Valvoline quick-lube. I suspect they may
have missed the U-joints from time to time. Anybody
out there know about this lube ? Are there plugs or nipples
on
these joints ? If plugs, should you replace them with
nipples ?
Although I have the factory service manual, it doesn't
contain a good chassis lube chart. Anybody know where
I can get one ? Appreciate your help.