Zodiac 6-speed conversion kits for Big Twin with 5-speed gearbox and complete 6-speed transmissions for Softail — B-stock

Offered item / B-stock. Non-refundable, non-returnable, no warranty. Limited stock.

The main disadvantage of 5-speed gearboxes is likely the 1:1 ratio in 5th gear, resulting in high engine revs at high speeds. You can change this by altering the secondary transmission ratio, but this also affects acceleration. With the new 6-speed Zodiac gearbox, you have a 1:1 ratio in 5th gear, but in 6th you have a ratio of 1:0.86, reducing engine revs by 14%. Other 6-speed gearboxes are available on the market, but none match the quality of the Zodiac 6-speed, nor are they as economical, nor do they possess the same CAD/CAM design and manufacturing quality as Zodiac gearboxes. The components are CNC-machined in the world’s most modern transmission factory. All gears feature very smooth tooth surfaces to ensure smooth and trouble-free operation for many thousands of miles.

The Zodiac 6-speed gearbox is compatible with Dyna 5-speed models from 1991 to 2005 and Softail models from 1986 to 2006, provided a clutch from 1990 onwards is used. Available as a conversion kit, a builder kit, and a complete gearbox. The conversion kit includes the main shaft, secondary shaft, and sixth gear combination, complete selector drum mechanism, a pair of selector supports, shift fork, auxiliary selector fork with shift shaft and shift shaft support, shift locking system, clutch rod, billet aluminium gearbox cover with bearing plate, main shaft, 1st, 2nd, 3rd and 4th gears, speedometer plug with O-ring, and all necessary mounting hardware and easy-to-understand instructions for installing the Overdrive Conversion Kit on a Softail gearbox, using some parts from the original gearbox. If you do not wish to use any parts from your old gearbox, or if the gearbox is pre-1990, you can order our "Builders Kit", also available with a 25, 45 or 55mm longer shaft. These kits include all primary spacing components, such as spacers, crankshaft extension, and crankshaft extension nut. They do not include the sump, seals, bearings, final cover with clutch mechanism, top cover, or any external parts. For those starting from scratch, we also offer complete 6-speed gearboxes. These gearboxes are suitable for models with electronic speedometers and include a plug for the sensor hole if you wish to use a conventional cable-driven speedometer, whether sourced from the front or rear wheel.    Where the difference lies:  •All sprockets from first to fifth are the same width as the original sprockets •The sprockets and shafts are made from 20CrMnT steel, highly resistant to fatigue •The sprockets and shafts, once machined, are hardened and relieved of machining stress, to an inner hardness of 35 to 45 and a surface hardness of 58 to 60 on the Rockwell scale •The sixth sprocket and the secondary shaft are one single piece •The inner cover, machined from solid billet aluminium, allows the installation of the two extra sprockets •The selector drum is precision machined and features an oversize needle bearing •The gear locking mechanism has been redesigned for precise and smooth shifting •Excellent value for money •Now also available with a main shaft 25mm, 45mm or 55mm longer •5 years or 100,000 KM warranty on the material    All seals, retainers and O-rings are the same as for the original 5-speed transmissions.


Specifications


Pack
1


HS Code
8714109090


Origin
US