well...found a bit more time after dinner to put the hpi rear ball diff together. got the caps and wiring soldered onto the speed 480 race motor and mounted it to CF motor plate...sanded down the axle carrier and pieced everything together.
tested the 16T pinion and spur meshing - still need to sand down the axle carrier another 1mm to get the 16T meshing to work properly - I'll do that later. I got the 24T pinion installed and tested the spur meshing.
In spinning the meshed gears, I found the meshing to be a bit gritty no matter how well I positioned the motor on the CF motorplate.
The motor plate has screw slots (not holes) on both locations and it just felt a tad gritty when I spun it by hand.
But upon closer inspection of the meshing, via magnifying glass, the meshing seems to be fine.
two questions I have...
(1) With this gritty meshing, is it just me or anyone else with the sleeper, experience this?
(2) with the pinion on the race480 motor, is it recommended that a flat spot be sanded on the motor shaft so the pinion set screw has a spot to bite down on?