I've heard stories about pinion gears breaking due to the location of the keyway in certain reproduction pinion gears being directly under a tooth so that the path from the corners of the keyway are shorter to valley on each side of the tooth above the keyway. True or not?? Thanks : Bruce
I have heard the same, but the only pinion gear I have had break was an original Ford gear, and it split in half (one side of the split was off a key-way corner)
Likely matter of time before stress of starting and stopping takes a toll on this pinion gear.
Better machining is the Ford way. Ford pinion on right, good repro on left.
The corner in the key way is a stress riser no matter where it is. It is true that a crack would have a shorter distance to travel if the keyway is under a tooth, but the actual distance difference is not much either way. If a crack develops, the gear will break. I would think proper heat treating and annealling would be the most critical factor.
There were also a run of ring gears with the screw holes in between the teeth that would allow the pinion to hit the screw heads I have one and so far all is OK.
Rick - the 39 tooth ring gears always has some of the screws in between the teeth since ten screws doesn't fit evenly among 39, so the pinion teeth has to be beveled to clear when setting up a 3:1 rear axle.
Roger, this is a 40 tooth std ring gear.
Off the top of my head, whey didn't they radius the corners a bit and radius the key a bit?