I think I would use the locking bolt. Without it, the u-joint could slide on the splines and wear more than originally engineered.

A suggestion: since this is related to your other post(s) about the u-joint on your truck, it would make sense to reply in the same thread, keeping the related questions together.


Kevin
1951 Chevy 3100 work truck
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1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car)
Busting rust since the mid-60's
If you're smart enough to take it apart, you darn well better be smart enough to put it back together.