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OD6: Overdrive 6-Speed Complete Transmission

* Limited supply of chrome bearing doors available. Please give us a call at 517-339-3835 to order a chrome bearing door.

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 today's 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.

If you are looking for a transmission replacement with a tapered mainshaft, we offer a 5-speed gearset and 5-speed complete transmission.

  • 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
  • 1990-97 Softail
  • 1998-99 Softail


  • Stronger than stock
  • Lower RPM for smoother highway speeds
  • Fuel efficiency



          Bearing Door
          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.


          OD6 Ear & No Ear Bearing Door

          OD6 Bearing Door vs. Stock

          Thickness Comparison

          Redundant Neutral System

          Shift System
          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’ 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. Use the image on the far right for reference. This is very important to know if you need any replacement parts or components.

          OD6 Gearset Layout

          OD6 1st Gear Ratio

          The OD6 comes in a standard, optional or R-Ratio configuration 

          Standard Ratios
          1st Gear 2.94 
          2nd Gear 2.21
          3rd Gear 1.60
          4th Gear 1.23
          5th Gear 1.00
          6th Gear .86


          OD6 Shift Forks

          Shift Forks
          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) 



            Complete Build Part Numbers

            All Part Numbers Listed Are Standard 2.94 Gear Ratios

            New PN Old PN Description Fitment
            OD6-701 701 OD6 Complete Transmission 1990-97 Softail
            OD6-801 801 OD6 Complete Transmission 1998-99 Softail


            Complete Build Notes

            • The OD6 is available with a deep overdrive gear.80 6th; Please speak with our technical staff before picking this option; this is typically for big inch motor applications only.
            • Complete OD6 FLT-FLH transmissions come with Function Formed FL oil spout and dip stick 

            Complete Build Case Finish Options


            Raw Finish


            Wrinkle Black Finish


            Show Polished Finish

            Add suffix to the end of the part number, ‘02’ for Polished, ‘06’ for Raw and ‘03’ for Wrinkle Black


            BAKER Case vs. Aftermarket

            Case Design
            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. 

            Exhaust Bracket

            Exhaust Bracket
            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

            Special Note

            • Speedo recalibration unit is required for electric speed sensor applications; PN 95E-56B. 

            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

            OD6 vs. DD6

            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

            Learn more about Spectro Performance Oils here:

            Installation Instructions

            OD6 installation instructions with exploded views: Click Here

            OD6R Exploded View Diagram addendum:
            OD6R Addendum with exploded views:  Click Here

            Installation Note:

            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 555-56LD (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 517-339-3835.

            1st Gear Design Change

            1st Gear Change Addendum-March 2012: Click Here


            BAKER Drivetrain reserves the right to change prices, terms or policies at any time without notice. Orders can be pre-paid using Visa, MasterCard, American Express, Discover or PayPal. All orders not pre-paid will be sent C.O.D. certified check or money order only unless pre-approved for company check acceptance. Any orders from outside the USA must be pre-paid in US funds via wire transfer; a $30 transfer fee will apply. Prices shown are F.O.B. Haslett, MI.


            BAKER™ transmission assemblies and transmission builder 's kits, are guaranteed to the original purchaser to be free of manufacturing defects in materials and workmanship for a period of 5 years from the date of purchase or up to 50,000 miles, whichever occurs first. All other BAKER products are guaranteed to the original purchaser to be free of manufacturing defects in materials and workmanship for a period of 2 years from the date of purchase or up to 24,000 miles, whichever occurs first, except for the following; Warranty does not cover clutch plate wear, throw out bearing failures or mainshaft breakage due to improper clutch nut installation.Electrical components carry a 30-day warranty; cosmetic finishes (chrome plating, hard anodizing, powder coating) are covered for 60 days. Certain promotional products may carry a shorter warranty as specified at the time of purchase. If the product is found by BAKER to be defective, such products will, at the option of BAKER, be replaced or repaired at cost to BAKER.In the event warranty service is required, the original purchaser must call or write BAKER immediately with a description of the problem. If it is deemed necessary for BAKER to make an evaluation to determine whether the transmission assembly or transmission kit or accessory is defective, the entire transmission assembly, whether originally purchased as an assembly or kit, must be properly packaged and returned prepaid to BAKER with a copy of the original purchase invoice. If after evaluation by BAKER a defect in materials and/or workmanship is found, BAKER will, at their option, repair or replace the defective part of the assembly.


            Returns are permitted within 90 days of the delivery date. Any merchandise returned for any reason (exchange, credit or modification) must be accompanied by a Return Goods Authorization (RGA) number or it will be refused. Call BAKER to obtain this number prior to returning goods for any reason. There is a 15% re-stocking fee for all returned items. BAKER is not liable for any shipping.


            NOTE: Limited warranty does not cover labor or other costs or expenses incidental to the repair and or replacement of BAKER products.This warranty does not apply if one or more of the following situations is judged by BAKER to be relevant: BAKER OEM transmissions ; (these are subject to the OEM manufacturers warranty only), Improper installation , accident, modification (including but not limited to use of unauthorized parts, transmission oils or lubricants), racing, high performance application, mishandling, misapplication, neglect (including but not limited to improper maintenance), or improper repair.BAKER shall not be liable for any consequential or incidental damages arising out of or in connection with a BAKER transmission assembly, transmission kit, component or part. Consequential damages shall include without limitation, loss of use, income or profit, or losses sustained as the result of injury (including death) to any person or loss of or damage to property.BAKER transmissions, transmission kits and accessories are designed exclusively for use in American V-Twin motorcycles. BAKER shall have no warranty or liability obligation if BAKER parts are used in any other application.If it is determined that a BAKER product has been disassembled during the warranty period for any reason, this limited warranty will no longer apply unless you were instructed to do so by a BAKER Drivetrain technician for diagnostic purposes.

            OD6: Overdrive 6-Speed Complete Transmission
            Move your mouse over image to zoom. Click to enlarge.
            OD6: Overdrive 6-Speed Complete Transmission OD6: Overdrive 6-Speed Complete Transmission for 1986-2006 Harley-Davidson motorcycles Big Twin OD6: Overdrive 6-Speed Complete Transmission for 1986-2006 Harley-Davidson motorcycles Big Twin OD6: Overdrive 6-Speed Complete Transmission for 1986-2006 Harley-Davidson motorcycles Big Twin OD6: Overdrive 6-Speed Complete Transmission for 1986-2006 Harley-Davidson motorcycles Big Twin OD6: Overdrive 6-Speed Complete Transmission for 1986-2006 Harley-Davidson motorcycles Big Twin OD6: Overdrive 6-Speed Complete Transmission for 1986-2006 Harley-Davidson motorcycles Big Twin OD6: Overdrive 6-Speed Complete Transmission for 1986-2006 Harley-Davidson motorcycles Big Twin OD6: Overdrive 6-Speed Complete Transmission for 1986-2006 Harley-Davidson motorcycles Big Twin OD6: Overdrive 6-Speed Complete Transmission for 1986-2006 Harley-Davidson motorcycles Big Twin
            Customer Reviews
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            Rick B.
            United States
            • What model motorcycle do you ride? 2003 Big Dog Chopper

            Nice trans

            Great trans, will have no other.Good customer service,answered all my questions.This is my second baker tranny and I love it.

            Tom B.
            United States United States
            • What model motorcycle do you ride? Harley davidson FXR

            FXR transmission

            Hard to find FXR transmission looks and works great

            Xavier M.
            United States United States
            • What model motorcycle do you ride? 53,94,90

            The Best

            Always Great service and the products speak for themselves PERIOD!!!!

            Mike W.
            United States
            • What model motorcycle do you ride? Which one

            Customer Service

            Your product is good, your customer service needs work

            Gil M.
            United States

            Fxr 6speed

            This trans is amazing

            Web Product ID: 5546442819
            Baker Drivetrain Team Illustration