OK, bad news. :007: The Kyosho spur physically fits, but is quite a bit too thick to fit the diff holder. The steel spur is formed differently to be as thin as possible - way thinner than the Hyper 8 spur for example. Not only that, but the existing diff doesn't use your typical sized bearings. The stock bearings are 15x10x4 (OD/ID/W) compared to whatever size the typical diffs are. So, my choices are:
- Try to find bearings that will fit the stock mount with the Kyosho diff. I would need 15x8x4 (od/id/w) bearings, which I cannot find for some reason, not even at Avid. If I go with this plan, the diff mount has to be moved back a little (not a big deal) and I'd have to modify the Kyosho spur since the diff outdrive is too short to go all the way through the Kyosho spur and still be able to use the retaining pin (inside the diff).
- Keep using the existing diff with the steel spur, get a steel pinion, and take my chances with the wear. However, 1/8" bore Mod1 pinions are not available anywhere.
- Get a regular center diff with mount (although I think I can use the stock mount from my Hyper 8), install the Kyosho spur, and remake the motor mount.
Neither of these options is very appealing, but #3 sounds like the best bet from a part availability standpoint. Option #2 sounds like the easiest, but the pinion is not available and I'm not sure on the steel-on-steel idea.
Any suggestions or other alternatives?