Deathtrap Customs A/S

The biggest disadvantage of the stock 5 Speed transmission might be the 1 to 1 gear ratio in fifth gear, resulting in high engine RPM when cruising at high speed. O.K, you can reduce this by changing the final drive ratio, but this will also reduce acceleration. With the new Zodiac Six speed you will have the 1 to 1 gear ratio in 5th gear but 1 to 0,86 ratio in 6th, reducing engine speed with as much as 14%. There are other 6 Speed conversions on the market, but not as economically priced nor have the quality in engineering and CAD/CAM design as the Zodiac Six. These precision parts are CNC manufactured by one of the worlds leading automotive transmission factories. All gears have a smooth tooth surface that guarantees a noiseless and trouble free transmission for tens of thousands of miles.

The Zodiac Six fits all 5 Speed Dyna transmissions from 1991 thru 1998, and Softail transmissions from 1986 thru 2006 when used in combination with a 1990 to present clutch. Available as a conversion kit, a builders kit and as a complete transmission. The Conversion Kit contains main shaft, counter shaft and 6th gear combination, shifter drum, a pair of pillow blocks, complete shifter drum lock mechanism, right hand side center shifter fork, auxiliary shifter fork with shift axle and shifter shaft support, shift locking system, clutch rod, Billet aluminum trap door with bearing lock plate, main shaft 1st, 3rd, 4th and 6th gear, counter shaft 1st, 3rd, and 4th gear, trap door speedo plug with O-ring, and all required hardware, as well as comprehensive instructions how to install the Overdrive Conversion Kit into a Softail transmission, re-using some parts of your own transmission. When you do not want to re-use these parts or when you have a pre-1990 transmission you may want to order one of our Builders Kits. Builder's kits are also available in 25, 45mm or 55mm offset. The offset kits come complete with all parts to offset the primary, such as spacers, crankshaft extension and crankshaft extension nut. Except for the transmission housing with seals and bearing, the end cover with clutch mechanism, the top cover nor any part bolted to the outside, the builders kit contains all parts to build a complete new transmission. For those starting from scratch we also have complete and ready-to-install 6 Speed transmissions available. These can be used with or without electronic speedo pick up as they come with a billet aluminum plug to plug off the pick up hole in the trap door when using a front or rear wheel driven speedo.

What the difference is:

•Gears from 1st thru 5th speed are exactly the same width as stock gears
•Gears and shafts made from High Stress 20CrMnT gear steel
•Gears and shafts tempered and stress released to a core hardness of 35 to 45 Rockwell and a surface hardness of 58 to 60 Rockwell
•Six speed counter shaft gear is a one-piece construction with the shaft
•Fat Billet Aluminum trap door that enables the installation of the extra pair of gears
•Precision machined shifter drum with oversized needle bearing
•State of the art shift locking mechanism for precise and positive shifting
•Un-compromised price to quality ratio
•Also available with 25mm, 45mm or 55mm extended main shaft for offset applications
•5 year or 100,000 KM warranty on material failure

All gaskets, seals, and o-rings are the same as for stock 5 Speed transmissions


6 Speed conversion kit, fits 1994-2006 Softail and 1994-1998 Dyna
Article number Description Retail price Add to list
Six Speed Conversion Kit
Six Speed Conversion kit complete with 45mm primary offset kit
6 Speed Builders kit, fits 1990-2006 Softail and 1991-1998 Dyna. Offset kits include all required primary offset parts
Article number Description Retail price Add to list
6 Speed kit
6 Speed kit with 25mm offset
6 Speed kit with 45mm offset
6 Speed kit with 55mm offset
Note 1: 2000 and later Softail models require some extra parts for the conversion that must be ordered separately. These parts are available in a kit as well as individually.

Note 2: Must be used with an electronic speedometer adjuster/calibrator when used with an OEM or other non-adjustable electronic speedo.

Additional kit for 2000-up Softail 6 Speed conversion kit
Article number Description Retail price Add to list
Additional kit for 2000 up Softail models
Individual parts for additional kit for 2000 up 6 Speed conversion kit
Article number Description Retail price Add to list
Transmission ratchet assembly, Genuine Zodiac, 2 Year Warranty
Ratchet adjusting bolt, Genuine Zodiac (OEM 33119‑79A)
Ratchet adjusting bolt, V-Twin Mfg. (OEM 33119‑79A)
Adjusting bolt lock nut
Top Cover
Neutral switch
Individual parts for Zodiac 6 Speed transmissions
Article number Description Retail price Add to list
Main shaft
25mm Extended main shaft
45mm Extended main shaft
55mm Extended main shaft
Main shaft 1st gear
1st. Gear main shaft (OEM 35025‑79B)
Main shaft 3rd gear
Main shaft 4th gear
Main shaft 5th gear (OEM 35029‑94)
25mm Extended main shaft 5th gear. Also used for 45mm offset kits in conjunction with a 3/4" offset drive pulley
55mm Extended main shaft 5th gear
3/4" offset 32 tooth drive pulley
25mm Extended pulley spacer
55mm extended pulley spacer
6th gear main shaft
Counter shaft with integrated 6th gear
1st gear counter shaft
2nd Gear counter shaft (OEM 35027‑94)
Counter shaft 3rd gear
Counter shaft 4th gear
Counter shaft 5th Gear (OEM 35626‑94)
Shim, main shaft right side
Split cage needle bearing main & counter
Retaining ring, Jims USA, 10 pack
Needle bearing main drive gear
Main drive seal (OEM 12035B)
Main drive seal, 10-pack (OEM 12035B)
Thrust washer, Jims, 5 pack (OEM 6003)
Thrust washer, Eastern, 5 pack (OEM 6003)
Trapdoor with bearings & bearing plate
Article number Description Retail price Add to list
Trap door bearing plate
Trap door bearing plate screw, each (2 required)
Replacement bearing (each) (OEM8992A)
Bearing, mainshaft left (OEM 8998)
Trap door pipe plug (OEM 739A)
Plug for speed sensor hole
O-ring for speed sensor hole plug
Auxiliary shifter shaft support
Auxiliary shifter shaft axle
Article number Description Retail price Add to list
Auxiliary shifter fork
Shifter fork
Shifter fork 2nd mainshaft
Shifter fork, Auxiliary shifter fork, Shifter fork 2nd mainshaft & Shifter fork 3rd mainshaft
Shifter drum
Pillow block, left
Pillow block, right
Dowel pin, right side pillow block
Clutch rod, bearing side
Clutch push rod center (OEM 37088‑90)
25mm Extended clutch push rod
45mm extended clutch push rod
Pushrod, 55mm extended
Pushrod bearing kit
Transmission ratchet assembly, Genuine Zodiac, 2 Year Warranty
Retaining ring, ratchet (OEM 11150)
Washer, ratchet (OEM 6497HW)
Shift fork shaft (OEM 34088‑87)
Replacement parts for TPD 6-speed conversion kits supplied before 2004
The first series of our 6-speed conversions have the auxiliary shifter shaft for the 6th gear fitted with two bolts to the inside of the trap door. Listed parts can not be used in late conversion kits.
Article number Description Retail price Add to list
Shift locking system with right side pillow block
Pillow block, left
Replacement bearing (each) (OEM8992A)
Trap door bearing plate
Shifter fork 3rd. & 5th., Eastern USA (OEM 34193‑79C thru E)
Shifter fork 1st. & 2nd., Eastern USA (OEM 34191‑79C thru E)

Recommended Retail Prices include 25% sales tax.

Prices exclude shipping, import duties and installation.

Prices are based on EUR to NOK interbank rates obtained daily. The interbank rate is the rate that banks trade currency to each other. These prices must be used as a guide.