To insure truck universal joints receiving ample lubrication, an extra boss has been placed in the torque tube to accommodate an additional lubricator fitting which is installed just back of the universal joint ball cap. This fitting permits the lubricant to flow directly to the joint without first passing through the bearing.
Any stock of truck torque tubes you have on hand should be drilled and tapped and lubricator fittings installed. The new fitting is installed exactly 2″ forward from the center of the hole for the present grease fitting. (See Fig. 924.)
When drilling the hole, use a 21/64” drill and tap with a 1⁄8” taper pipe tap. This will make the lower end of the threaded hole slightly undersize and prevent the lubricator fitting protruding into the housing and interfering with the removal of the bearing.