I recently had the same issue with my 1970 roadrunner. i took column out to do some work on it. when i went to install the steering wheel shaft was too short. it drove me crazy for days. i kept taking it out of car . it fit into coupler fine but something was not right. i finally realized i somehow collapsed the internal steering shaft. i pulled shaft out a little and put everything back. i now have no issues. i would not worry about the nylon shearing off. you will be fine without it
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