I took the motor in to an electric motor shop, and they popped the hub off as easy as opening a pickle jar! They didnt even need to heat it up. They would have been willing to do it for free, so I was back on track for just a morning spent driving around and some beer money for the very helpful guys down at Advance Electric Motors.
I would only be concerned if this causes the transmission input shaft to bottom out in the adapter.I had measured the critical distance as 21.2mm when I took the motor apart - now I am getting 22.3mm. How precise should I strive to be here?
Since a clutch lasts at least half the life of a car, I've never replaced a clutch disk more than once... and not resurfaced the flywheel except in the one case that we were also lightening the flywheel.It seems like it is generally recommended to have the flywheel resurfaced anytime you have it out of the vehicle, anyway, so should I have it shaved down by about a mm to get closer to my original value? Also, is there any value in having them mill off extra weight, like the gear teeth, for example? I might also put in a new clutch disc, as the one in there is getting pretty close to needing replacement (I think).
Yes, although it's certainly not necessary when you have a clutch. Flywheels exist primarily to add rotational inertia; mounting the clutch is secondary. Flywheel inertia smooths out the pulses of an engine, and makes it easier to start off from a standstill without stalling; neither of these applies to an electric motor. Flywheel inertia just stores kinetic energy, making the car behave as if it were a bit more massive when changing speed.Also, is there any value in having them mill off extra weight, like the gear teeth, for example?
Even with an engine the flywheel is routinely far heavier than it needs to be: I had half the weight taken out of our Honda's flywheel when preparing it for competition, and it still wasn't rough or hard to drive after that.
The ring gear is commonly a shrink-fit on the flywheel - in that case, it can be removed without machining work, and makes a significant contribution to interia.