hole in the PTO shaft

[Mosey]

There is a hole in the PTO shaft on my NH TC29D. Do all tractors have this hole? What is it for? I’m guessing it could be used on some implements instead of a spring loaded lock pin on the outside of the yoke to keep the PTO shaft in place.

[beenthere]

You are right, as 'in the old days' (when we walked to school, etc, etc, ) we used a bolt to hold the pto shaft together. No fancy slip lock or spring loaded pin such as nowadays. Probably still there to adapt to some of the older attachments.

[Surge]

It is used to hold PTO attachments.... For example an overrunning clutch would use the hole as it would have a pin that would slide through the PTO shaft. You then have zirc fittings that allow you to grease the pin....

[frank_f15]

some of the old tractors had such a hole it was to keep the pto shft on the pto. a small bolt went though it . was no spring loaded pins back then

[jinman]

Mosey, on many PTO adapters, a spring-loaded pin fits into the groove cut into the spline teeth on your PTO shaft. The hole is for an additonal safety pin much like the one on a bulldog style trailer hitch. Then if you get vines wrapped around your PTO shaft and they happen to squeeze and release the spring-loaded pin, the safety pin keeps the PTO shaft and adapter locked together. It is true that this hole is used for the rollpin of an overrun clutch, but the PTO spline on the overrun clutch also has a hole in it just like the one on the tractor. I hope this helps.

[Mosey]

OK, that all makes sense. Thanks!