Modding the HPI Cup Racer for a Front One Way, part3

Some additional grinding, and the Eagle Racing TT-01 one way fits!

 widen the axle cup openings

The dogbone pins are too thick to fit the drive cups. Use a Dremel sanding disk to slowly remove material. Check often until you have a smooth fit. I ended up with a bit of slop on the pins, and will move to blades when they wear in.




 

Plunge and enlarge the center hole

After the fit is good, a new obstacle presents itself - the dogbone is too wide to fit into the axle cup. Use a tapered or other Dremel grinding stone to enlarge the cup center bore. Again, go slowly and check fit often.

check for binding before install

 nice gear mesh

Check everything for fit  before final assembly. Add a high quality grease to the CVDs to reduce friction and wear.