The Chief-Overdrive aftermarket 4-speed trasmission was designed to enhance the rideability of Indian Chief motorcycles.  The transmission is the perfect solution for anyone wanting to take longer cruises at higher speeds or just have a more reliable transmission than the stock or 3-speed rebuild for their classic ride.

This transmission has three gears with similar ratios as the OEM trans and a fourth gear that enables the bike to go 72 mph with the engine at 2950 rpm using a large drive sprocket and a standard high profile tire. The 356-T6 gearbox case design is externally the same as the original case with the interior beefed up to accept larger bearings. The top cover has a thicker flange to incorporate the new gear change mechanism. The detent mechanism uses a roller to eliminate friction. 

 

  • The transmission is self contained and sealed. A new clutch basket is included allowing the clutch to be shimmed without opening the trans case.

  • Smooth shifting up or down. No more jamming it into gear and breaking parts.

  • Solid detents for all four gears and neutral.

  • Shift pattern unchanged.

  • Replaced the taper and woodruff key on the clutch input shaft with an involute spline.

  • Replaced the old style sprocket six lobe spline with a larger involute spline.

  • Output sprocket, your choice of 19,21,23,24,25 or 26 teeth provided with trans.

  • The oil fill and vent plug is on the case cover, and a magnetic drain plug in the bottom with an oil level check plug on the lower right front of the case.

  • The Transmission is isolated from clutch assembly so each can use different lubricants,eg: 85-90W synthetic gear oil in the trans and HD clutch oil in the clutch assy.

Click here to download the PDF flyer