Shifter Cone Screw Keeps Loosening, Thread Locker or Worn? Options

[Spoke]

Every 6 months I have to retighten the cone screw on the shifter. This time it came out real quick. I thought it might come out all together. I couldn't get 2nd without hitting reverse. The picture shows how much the screw backed out.

Not sure how much torque I applied but I was bending the allen wrench.

Questions:

Should I have thread locker on this?

What is the torque required for the cone screw?

Possible that the threads have been widened by repeated looseness?

Why didn't they put a bolt through this to really lock the hub onto the shaft?


TIA

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[Superhawk996]

Why didn't they put a bolt through this to really lock the hub onto the shaft?

The conical screw provides a positive indexing that couldn’t be obtained by simply matching a flat on the shift rod or using a hole and a through bolt.

The amount of torque that can be used is limited by the material used and the size of the fastener. Again, a bolt of the same size (M6 if I recall) offers no advantage over the conical set screw.

The conical set screw seating into the pocket on the shaft offers positive retention. Should it loosen, the coupler can’t become disconnected from the shaft even though things get terribly sloppy well before the screw could fall out alllowing for a disconnect to occur. This is a very safe failure mode.