[lurkingknight]

a spring change is a spring change... not a shim job and a spring change. IF the shimming was untouched, factory shimming isn't that great from most manufacturers.

After hearing it in the video... try adjusting your motor height up and down. It's sounding like high pitched pinion/bevel meshing. If you can't get the higher pitched whine out then it needs a shim job.

As you adjust the motor height up or down the cycle will get higher or lower pitched until it starts to get higher again or if you go too low you'll get a bit of a grind as the pinion leaves the bevel gear entirely. You want to find the quietest pitch that is in the middle.

Also if you orient the gearbox so it's on its left side and shoot a few cycles vs right side vs normal shooting orientation, does the pitch change at all? If it changes without changing the motor height, then the shimming is too loose and the relationship between the 3 changes as the gear facess start resting on each other.

If the pitch doesnt' change before or after messing with the motor height, then the shimming is likely too tight. Gears are generally shimmed loose from factory.