Hup 32 Driveshaft

[Max BURKE]

G,day to all

When the late George Smith, an expert machinest with his own shop owned our Hup he made a precision job of converting the diff to modern timken bearings. All the slackness he removed.Now perhaps you know that the tailshaft inside the torque tube was made in three seperate pieces and spun together untill the generated heat welded them into one unit.Why? To enable a 1inch length of shaft to have larger end pieces for the front uni joint and at the rear for the pinion and its bearings which were Hyatt flexible roller.We measured six of these shafts and the most accurate had 80 thou runout and the worst had 125 thou.When we mounted the best in the lathe at anything over 1000 rpm it would try to jump the lathe off the floor.Why then did it take eighty years to break? It broke because the beautiful Timken bearings would not let the shaft self allign and it broke where the larger pinion section meets the one inch shaft at the weld. OK we repaired the shaft by joining it with a splined sleeve from Hardie Spicer and installing a seal to keep the front oil in front and the back oil in back.Wonderful and no vibration but it lasted only two years. Reason ,we did not understand that the internal splined sleeve had to be hardened before use and we were running it with minimum oil so it wore out the spline.Towed home on the trailer again.This time we used a universal joint in the line at the pinion end and added a phosper bronze bearing at the uni joint for extra support with an external grease nipple to ensure it gets lube.

We have now covered several thousand miles without trouble but i expect the rollers in the joint will be brinneling the cross from running in a nearly straight line.

Another well used 32 here did the same trick after the bearings were modenised.

Max Burke Nulkaba Australia