Well, built the diff. Doesn't seem to be leaking thru the O-rings area....
Actually looks like its leaking from the screw holes... Nearly all other gear diffs I built have had some sort of paper gasket between the halves that included surrounding the screw holes...
Is the BD7 diff more narrow than the Photon unit?
Its a little thicker. But you just remove one of the red shims from each side. Then you off set it to the right and will run true to the belts. Once you do it you will know what I mean, easy 2 second job. Also run the white Yok blades on the shafts.
Coxy.