THE ORIGINAL 6-SPEED TRANSMISSION
This is the ORIGINAL 6-speed design that revolutionized the American V-Twin industry. Yet, it’s still the best overdrive 6-speed built to this day…hands down. Our OD6 is built to comfortably handle the power from todays big-inch motors. This transmission is rated for motors putting out up to 165ft/lbs of continuous use. It is available as a complete transmission with a wide variety of case options and
configurations, or as a builder’s kit for your stock case application, which requires little to no modification. The BAKER OD6 is available with many optional gear ratios to match your engine torque and riding style.
– Billet 6061-T6 bearing door
– 1/8″ thick bearing retainer plate
– Redundant Neutral smooth shift system
– Hard chrome plated shift forks
– Diamond cut gearset made out of 8620 steel
– Optional Gear Ratios
– All transmission seals, gaskets and hardware
– 5 year limited warranty
OD6 bearing doors are a 1/2″ wider at the mounting flange then a stock 5-Speed door due to the 6th gear. The OD6 door comes with or without an ear. The ear door is for exhaust bracket mounting and does not fit 1993-2006 FL applications. Note the images below. The OD6 door bearings are larger providing 25% more dynamic load capacity than stock bearings used through 1998, also uses a 1/8″ bearing retainer plate instead of stock style snap rings.
Our 6 Speed shift system with roller detent guarantees smooth shifts every time and our redundant neutral ensures that finding neutral is a easy chore. We mount a plunger detent on the left side pillow block and cut a plunger track into the shift drum itself. The plunger follows this track during operation (shifting) and when shifting into neutral pops into a pocket. This system lets you feel that you’re shifting into neutral. No more guessing. Shift drum features more aggressive timing on the fork groove profiles and is case hardened to 58 Rockwell for wear resistance and crisp shifts. We built our reputation on smooth shifting 6-speed transmissions; our drum designs benefit from the engineering lessons learned.
FL Case Differentiations
To see an illustrated example of the differences between FL cases by year, please open the PDF here.
All OD6 gearsets are made out of 8620 steel, gears are shaper cut before heat treat then precision ground with diamond coated tooling after heat treat (58-62 Rockwell ‘C’). This extra steps ensures not only a quieter gear pair, but enables much tighter backlash control. This tighter control on the gears yield a silent operation.
The OD6 comes in a standard ‘2.94’, optional ‘3.24’ or R-Ratio ‘2.82’ configuration. A way to physically tell which ratio you have is pretty common knowledge here at BAKER, but if you would like to know look at the 1st gear pair on the gearset. Our standard 2.94 1st gear will not have a notch on the 1st countershaft gear, our (stock) 3.24 1st gear will have a single notch around the center of the 1st countershaft gear and our 2.82 (R-Ratio) 1st gear will have 2 notches around the 1st gear countershaft. Use the image on the far right for reference. This is very important to know if you need any replacement parts or components.
The OD6 comes in a standard, optional or R-Ratio configuration
|1st Gear||2.94 / Optional 3.24|
Our investment cast shift forks are made out of 4140 then dipped in a hard chrome plate bath for wear resistance, also designed with oil reliefs to ensure proper lubrication and wear resistance on fork blades and shift dogs.
Available No Cost Options
– Standard Shift Drum (1-N-2-3-4-5-6)
– N1 Shift Drum (N-1-2-3-4-5-6)
– Reverse Pattern Shift Drum (6-5-4-3-2-N-1)
Builder’s Kit Part Numbers
All Part Numbers Listed Are Standard 2.94 Gear Ratios
|T401||OD6 Builder’s Kit Tapered Shaft||1987-89 FLT-FLH, Softail & FXR|
|401||OD6 Builder’s Kit||1990-92 FLT-FLH1990-97 Softail1990-94 FXR1991-97 Dyna|
|401S||OD6 Builder’s Kit||1999 FXR1998 Dyna1998-99 Softail|
|401SP||OD6 Builder’s Kit||1999-00 Dyna|
|401P||OD6 Builder’s Kit||2000-06 Softail2001-05 Dyna|
|402||OD6 Builder’s Kit||1993-97 FLT-FLH|
|402S||OD6 Builder’s Kit||1998 FLT-FLH|
|404SP||OD6 Builder’s Kit||1999-00 FLT-FLH|
|404P||OD6 Builder’s Kit||2001 FLT-FLH|
|404P2||OD6 Builder’s Kit||2002-06 FLT-FLH|
Builder’s Kit Notes
– The OD6 is available with a 3.24 optional 1st gear ratio . Change the middle numeral ‘0’ to a ‘1’. example: 411P
– For R-Ratio gears change the middle number ‘0’ to ’21′; example 4214P
-We started providing install DVD’s with every builder’s kit starting in October 2012. At approximately 3:25 of the OD6 portion of the DVD, Bert talks about modifying the shifter pawl. This modification is related to the stock shifter pawl lever assembly (H-D PN 34972-02B) and the use of BAKER 5-6QSN & 5-6QLN shift drums. We now provide a shift drum BAKER PN 124-0D6, which supercedes the 5-6QSN, 5-6QLN Shift, 5-6QEN, 5-6QFN & 5-6QGN shift drums, that requires no shimming and works with BAKER shifter pawl 555-56C or 555-56L (depending on year or motorcycle) which we include in kits and on all BAKER complete builder’s kits. We do not sell any kits, shift drums or transmissions that require any shifter pawl with BAKER marked on it, that needs to be ground or modified anyway. Any questions, please call us at 877-640-2004.
Complete Build Part Numbers
All Part Numbers Listed Are Standard 2.94 Gear Ratios
|T701||OD6 Complete Trans Tapered Shaft||1987-89 Softail|
|T702||OD6 Complete Trans Tapered Shaft||1987-89 FLT-FLH & FXR|
|701||OD6 Complete Transmission||1990-97 Softail|
|702||OD6 Complete Transmission||1990-94 FXR1990-92 FLT-FLH|
|703||OD6 Complete Transmission||1991-97 Dyna|
|704||OD6 Complete Transmission||1993-97 FLT-FLH|
|801||OD6 Complete Transmission||1998-99 Softail|
|803||OD6 Complete Transmission||1998 Dyna|
|804||OD6 Complete Transmission||1998 FLT-FLH|
|901||OD6 Complete Transmission||2000-06 Softail|
|902||OD6 Complete Transmission||1999 FXR|
|903||OD6 Complete Transmission||1999-00 Dyna|
|904||OD6 Complete Transmission||1999-00 FLT-FLH|
|003||OD6 Complete Transmission||2001-05 Dyna|
|004||OD6 Complete Transmission||2001 FLT-FLH|
|0042||OD6 Complete Transmission||2002-06 FLT-FLH|
Complete Build Notes
– The OD6 is available with a 3.24 optional 1st gear ratio for higher horse power applications. Change the middle numeral ‘0’ to a ‘1’. example: PN 914
– For R-Ratio gears change the middle number ‘0’ to ’21′; example 9214
– Complete OD6 FLT-FLH transmissions come with Function Formed FL oil spout and dip stick
Complete Build Case Finish Options
Add suffix to the end of the part number, ‘P’ for Polished, ‘R’ for Raw and ‘B’ for Wrinkle Black and ‘C’- Chrome finish (Chrome Available only on 1990-97 Softail Billet Cases); example: 701B
The BAKER Softail case design had all leak potentials in mind during the design. We added stud pads to the inside of the case so that the thread holes for the transmission studs were blind holes, NOT through holes like some aftermarket brands. Looking at the image on the right you can see the difference.
Due to the OD6 bearing door being a 1/2″ wider than stock some FLT / FLH models may require a modified exhaust bracket for the mounting of the exhaust to the bottom of the bearing door. This modified bracket is about a 5/8″ difference from stock to accommodate the new door width.This bracket is sold separately from the kit. BAKER PN 188-6
– Speedo recalibration unit is required for electric speed sensor applications; PN 95E-56A.
Compare the OD6
See the difference between other transmission kits and our OD6. Click Here for a PDF file comparing our DD6 and OD6 gearset against other manufactures.
Click on the image to Compare the OD6 and DD6 gearsets
– Function Formed Oil Spout (for 1993-Later FLT/FLH Models only)
– +1 Quart Oil Pan (for 1993-Later FLT/FLH Models only)
– Inner Primary High Torque Bearing Kit
– SP9: Street Performer 9 Plate Clutch
– King Kong Clutch
– Front or Rear Feed LSD Hydrualic Side Cover
– Function Formed LSD (Left Side Drive) Bearing Door
– Bully Derby Cover (1999-2006 5 Hole Derby Cover Models)
-Truss Style Shift Lever
Click on any of the images below to learn more
Recommended Fluid / Level
Picking the right transmission fluid ensures the life and durability of your transmission, that’s why BAKER recommends a fully synthetic GL-5 rated gear weight oil of 75W-140. If a GL-5 rated gear lube is not available, these commonly carried viscosities (weights) will work 75W-90, 75W-140 and 85W-140. BAKER does not recommend the use of Syn3 (20W-50). For Bert’s article on ‘Oil & Spiders’ Click Here
BAKER OD6 Fluid Capacity Dry: 22-24fl-oz
BAKER OD6 Fluid Capacity Wet: 18-22fl-oz
OD6 installation instructions with exploded views:Click Here
OD6R Exploded View Diagram addendum:
OD6R Addendum with exploded views: Click Here
We started providing install DVD’s with every builder’s kit starting in October 2012. At approximately 3:25 of the OD6 portion of the DVD, Bert talks about modifying the shifter pawl. This modification is related to the stock shifter pawl lever assembly (H-D PN 34972-02B) and the use of BAKER 5-6QSN & 5-6QLN shift drums. We now provide a shift drum BAKER PN 124-0D6, which supercedes the 5-6QSN, 5-6QLN Shift, 5-6QEN, 5-6QFN & 5-6QGN shift drums, that requires no shimming and works with BAKER shifter pawl 555-56C or 555-56L (depending on year or motorcycle) which we include in kits and on all BAKER complete builder’s kits. We do not sell any kits, shift drums or transmissions that require any shifter pawl with BAKER marked on it, that needs to be ground or modified anyway. Any questions, please call us at 877-640-2004.
1st Gear Design Change
1st Gear Change Addendum-March 2012: Click Here
Morning James, you answered a bunch of questions for me last week about a 401-G that I bought. I finished the install on Sunday and took it out, OMG!!!! I thought there was something wrong when I first started it, I dropped it in gear and there was no klunk, I thought, it cannot be in gear. When I got out on the road I cannot believe how smooth the shift is, it almost shifts itself. You guy’s should build all the transmissions for Harley. I had been told by a local indie/friend that I should drop the front belt pulley by one tooth, which I did, it makes the new 1st gear seem closer to the original, I know I give up some RPM on the highway with this, but I cannot be happier. It went in a 92 Fatboy with about 50k miles so I replaced everything with new including the final drive belt. I love the 6th gear, I can roll at 70 mph now and not feel like the engine is screaming, it even brought the RPM down to where the mirrors on the ape hangers do not vibrate.
A little background on me I own and operate a hot rod & custom shop in Glenwood Maryland called J&M RodWorks and I deal with a number of high end manufacturers. My customers are very demanding of the highest quality and we have a lot of repeat customers. Most customers have me build one car and then come back for a second and one customer I have built 5 cars for. We have been featured in Street Rodder, Custom Rodder, Hot Rod, American Rodder and countless books. We have won awards at the Detroit Autorama and the Grand National Roadster Show in LA. We have been Street Rodder top 10 4 times and recently was in the top 10 for Street Rod of the year with a 1950 Ford Coupe Mild Custom.
Baker Drivetrain has been the best experiance I have had and I would like to thank you for your help with this project. The directions were clear and the machine work is top notch. I should not have waited for my trans to break, I should have done this when I got the bike.