I take it the grease nipple is to lubricate the differential regularly instead of just grease-packing it on initial assembly? So the surplus oozes out between the sprocket mounting collar and the axle shaft? And is that lithium general purpose chassis grease you've used? (It's white, which is the reason I made that guess.) Is that the recommended lubricant?
Are you going to make a similar rebuild/redesign of some other parts of the machine, notably the steering system, which seems to need it far more than the rear axle?
