Grafting feedscrew (Q from a new guy)

[f350ca]

I'd go for a shrink fit, a pin through it would give you a degree of confidence but probably not necessary. Cut the old shaft at the thread then drill, bore and finally ream the hole to 5/8 to the depth of the gear. Boring it will ensure the hole is in line with the shaft, drilling alone won't. Machine end of the new thread 2 to 2 1/2 thou oversize. Heat the end of the old shaft but try and keep the gear cool. Slip them together and chill the gear with a wet rag. Looks like you could get an inch or two of depth, I'd never expect them to come apart with the loads you'd be applying.