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T-MAXX Electric Conversion

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Revo Transmission Mod Options

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Traxxas Revo 2.5 Transmission Options

locked Trans Image showing how the transmission was locked into second gear:

Because many ask how to use the stock transmission for a brushless conversion, here are the various options. Each method has advantages and disadvantages depending on what you want:
    • Option 1: Modify the transmission for single speed (2nd gear):
      Lock the centrifugal clutch into second gear. See locking mechanism above this section. You don't have to, but you can also remove first gear altogether for a simpler and lighter tranny. Either way, 1st gear won't be used at all. Locking into second gear is the ONLY option where you can use the brake and/or reverse using the brushless motor.
    • Option 2: Two-speed transmission with stock brake and stock reverse:
      You'll need servos for the reverse shifter and the brake. The downside to this is that the reverse stock mechanism is generally pretty weak, especially since you're now using brushless. And you cannot use a center differential because the diff replaces the shift fork, dog gear, and second output gear. You can however still use the Optidrive to help protect against accidental reverse when moving.
    • Option 3: Two speed transmission with mechanical brake and no reverse (the cheap way):
      You'll still need a servo for the brake. Lock the shift fork somehow.
    Option 4: Two speed transmission with mechanical brake and no reverse (the right way):
    You'll still need a servo for the brake. Install the FOC (forward-only conversion) to eliminate reverse and get rid of the extra weight from the servo, Optidrive, assorted linkages, etc. This option lets you use a center differential if you want.

    Modify the transmission to Single Speed, 2nd gear only
    1. Remove first gear
    2. Install the FOC
    3. Install whatever gear set you want (std, wide, or narrow). Since each of these gear sets just adjusts 2nd gear, you can set a higher or lower ratio right off the bat to possibly allow better spur/pinion selections.
    4. Remove screw, spring, ball bearing, and little grey plastic plug on the centrifugal clutch.
    5. File three half-moon slots in the edge of the clutch lined up with three of the holes in second gear.
    6. Screw three 4mmX10mm pan head screws into second gear so they lock into the half moon cutouts you made on the clutch.
    And a simple diagram showing the basic parts before and after the single-speed conversion. Each of the seperate gears are color-coded for easy identification. Note: When the standard, wide, or narrow gear sets are used, only second gear is affected.