I tried to get something special for my red hotshot. I remember long ago someone made some ball differential for hotshot. I also know they cost a tons of $$ now, only if one is lucky to find them....
Then I saw a Paranoia Fox diff for sale here. I know fox and hotshot has the same 47 gear but the drive cups fits differently. But I decided some surgery is all it takes
The width of hotshot diff was approximately 15.9mm. This Paranoia fox diff was approximately 21.0mm in width. First, I removed that excess ~5mm width from the diff hubs. I heard that the original hotshot gear diff was a little tight, so I arbitrarily reduce the width of my ball diff so that the resulting width is approximately 15.4mm. At 15.4mm, the differential spins freely in the assembled gearbox
Then what I did was I sacrificed a pair of 959 wheel hubs, shaved it down to about 1mm thick in diameter. Opened up the diff to house the modified hubs, made sure I left about 1mm think material as well. Use some 0.75mm stainless steel wire to key the pieces together and bonded them with JB Weld epoxy. All these were done without a lathe, just hand held rotary tools. The challenge was to keep things center and true. Anyway, the result was rock solid!!!
A ball diff for the hotshot
