Saturday, August 22, 2009

F201 differential trouble

Putting the Castle Creations Sidewinder 4600kV in the F201 makes it go very very fast. But if you run it too long, you’ll melt your differential (at least the lightweight ones). I put the lightweight ones in when the cap screw broke on the standard kit ones. The lightweight diffs are too expensive to melt on a regular basis so I’m going to put the stock black can back on it. To be honest my skill level and the speed of the sidewinder don’t match when on a track ;P It was fun to blast in a parking lot though. I’ve now put the sidewinder in my TT-01D, we’ll see how that goes.


What greeted me inside the front gearbox.


Notice here how the top metal ring has been pushed into the plastic.


kit ones, with broken cap screw. non standard 2x15mm & 2x8mm cap screws are hard to find.

I wonder if there’s anything I could’ve done to prevent this? Regular maintenance is a pain on the rear diff. Tungsten and ceramic balls are over $20 and you need 2 sets, combined with lightweight diffs at $20 a piece. I’m sorry, but spending close to $100 is not in my “differential budget”.


  1. So what have you been doing? Replacing differentials with stock whenever the cap screw breaks? Mine just broke and I am looking for an alternative.

  2. I've just replaced with new screws. The F201 has been so hard to set up and generally fragile that I don't drive it much anymore. I have a ton of tires for it so I really should start driving it again :)

    7 digit part number for it is 9805845, Tamiya USA does not have any left. Google around, see if you find any and stock up.

    Kyosho *might* have an alternative part KYO1-S42015. No guarantees.