C3 - Drive shaft u joint bolts & lock washers

[Jim K.]

I am replacing the drive shaft u-joints on my 71 big block 4-speed. I have just removed the bolts on the drive shaft u joints (thanks to all for your help from my previous post!). The bolts were very loose and did not have lock washers. The half shafts had lock washers and was extremely tight.
Is the drive shaft u joints supposed to have lock washers? And why were these so loose? Thanks, Jim

[Jim T.]

Re: C3 - Drive shaft u joint bolts & lock washers

The factory installation used washers on the drive shaft u-joints. Your half-shafts did not leave the factory with lock washers, these were added by someone who had been there before you. The drive shaft nuts torque requirements are not real high, however because of their mounting position using a torque wrench is not probably used by most. Without looking it up I will guess that 20 ft lbs is what the service manual has for these nuts.

[Jim T.]

Re: C3 - Drive shaft u joint bolts & lock washers

Had to look up the torque of the nuts, 71 service manual has 15 ft. lbs for the half shafts and drive shaft to the differential and washers were used at the three locations. The half shaft mounting to the spindle did not use lock washers, but used the metal straps connecting two bolts and had tabs that were bent to the bolt flat. Torque is 75 ft. lbs.