It's just a slight end play problem and yes the rear bearing does take the pressure and wear a bit quicker, the crank also rubs the back plate when it moves back. I have seen a lot of wearing problems with the Evos and noticed a lot of filed shavings getting into the tank. By removing the baffle or using a different muffler without a baffle {not even sure the Evos still have the removable baffle?} most of the ground up goop is blown out the exhaust and doesn't get into the tank. If enough of those nasty little shavings get to the top end they will short out the glow plug. I even get a lot of colored goop after i do a rebuild on an engine, just not very much!!