I have stripped 5 Enfield gearboxes, and 3 out of 5 show very serious signs of wear.
Most of this wear is on the main shaft due to worn bearings; once the bearing starts to wear the shaft starts to move outwards, and then bangs in to the output shaft. British made gearbox shafts tend to chip bits off being made of harder metal, and Indian made shafts being softer metal tends to grind away to nothing.
One of the gearboxes went one further than that, the saft snapped at the same point of wear. This would leave the clutch loose to bang about or jam up in the primary cases.
The cure is a simple bearing change, paying particular attention to the smaller main shaft bearing; an enclosed needle roller bearing race would be a vast improvement in my opinion, but best check with RE clubs etc.
If you have an Enfield gearbox on your bike, take the outer primary case off and give the clutch a tug in and out, if there is excessive play this is what it will be.
Prevention is surely better than a cure.
Ian
