- Joined
- Jan 1, 2013
- Messages
- 87

I've found that the taper on the new Harris gearbox's mainshaft is wrong. I could detect some 'rock' when offering up the clutch hub (with drum & centre & rollers) when fitting the primary drive. It wasn't much, but seemed wrong. I reasoned that with a brand new Harris gearbox, it must be OK so went ahead and tightened the clutch nut (80 ft/lb). Next day (yesterday) the doubts got the better of me so I undid the clutch nut to see if the hub had seated firmly. It hadn't - the hub came off the taper without any effort at all - if I'd used it like this, it would have been relying completely on nut torque and the Woodruff key, which would not have lasted long.
I have other gearboxes including one with another brand new Harris mainshaft. I checked this. I offered up a new clutch hub and found, just like the other one, that it would rock. I pushed it onto the taper as hard as possible by hand and it doesn't bite. I tried the same new hub on a couple of good used (genuine) mainshafts and with just a bit of hand pressure, it locks tight enough to need firm thumb pressure to release it - just as you'd hope.
So, the Harris mainshafts have inaccurately ground tapers. Has anyone else used these mainshafts? Has anyone else come across, or heard about, this issue?
I have other gearboxes including one with another brand new Harris mainshaft. I checked this. I offered up a new clutch hub and found, just like the other one, that it would rock. I pushed it onto the taper as hard as possible by hand and it doesn't bite. I tried the same new hub on a couple of good used (genuine) mainshafts and with just a bit of hand pressure, it locks tight enough to need firm thumb pressure to release it - just as you'd hope.
So, the Harris mainshafts have inaccurately ground tapers. Has anyone else used these mainshafts? Has anyone else come across, or heard about, this issue?