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Factory 6-Speed Tapered Roller Bearing Kit

Heal your Achilles heel with the BAKER Main Drive Gear Bearing Kit for 2007-up Big Twins!


P/N 640-67

Kit includes

  • BAKER double tapered roller bearing assembly
  • Replacement HD main drive gear 
  • Replacement countershaft bearing


Main Drive Gear Bearing Kit Instructions

This kit provides everything you need to eliminate the all too common stock maindrive gear bearing failures. We include our exclusive BAKER double tapered roller bearing assembly, and a replacement cruise drive main drive gear.

Also available is a Transmission Rebuild Kit to go along with this double tapered roller bearing kit. P/N TRK-CD6-2


  • 2006 and later Stock Dyna 
  • 2007 and later Stock Softail / Touring

    Standard Gear Case Finish Examples (Not applicable to all products)




    Wrinkle Black

    These example finishes are intended to show the exterior treatments of cases, top covers and doors.

    TERM AND CONDITIONS                                                                                         

    • 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, transmission kits, primaries, and oil pans 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. BAKER™ clutches, kicker cover kits, belt drives, F6F kit, reverse systems, covers and accessories 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. 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 invoice of purchase. If after an evaluation has been made by BAKER™ and a defect in materials and/or workmanship is found, BAKER™  will, at BAKER™  option, repair or replace the defective part of the assembly. 


    Due to the uniqueness, low price and assembly outside of typical production process of products indicated as Insider Special products, purchasing these Insider Special products include a warranty so to guarantee the original purchaser to be free of manufacturing defects in materials and workmanship for a period of 1 year from the date of purchase or up to 12,000 miles. We have provided extended options for you to purchase below. 


    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 charges. 


    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 manufactures 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.

    The words H-D®, Softail®, FXR®, Dyna®, FLT®, FLH®, Sportster®, and Buell® are registered trademarks and are for reference only.

    Factory 6-Speed Tapered Roller Bearing Kit
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    Customer Reviews
    4.7 Based on 18 Reviews
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    Filter Reviews:
    United States United States
    • What model motorcycle do you ride? Roadglides forever.
    All American cycle

    Have used your tapered 6 speed transmission set up in 2 of my big engine Roadglides. We also recommend that bearing set up to our customers.

    Don L.
    United States United States
    good stuff

    We've used several of them and they are our replacement of choice.

    Trey H.
    United States United States
    6 speed main drive gear bearing upgrade

    Excellent product. The factory bearing is prone to failure. This part will resolve the issue. We have installed several of these in customers bikes with great results. Thanks to Baker Drivetrain for your products! Oceana Cycles,Inc. Virginia Beach,VA

    BAKER Drivetrain Factory 6-Speed Tapered Roller Bearing Kit ReviewBAKER Drivetrain Factory 6-Speed Tapered Roller Bearing Kit Review
    Rick T.
    United States United States
    Put to the test

    I installed this kit on a local police department 2007 FLHT. No complaints. If it holds up under these guys it is a success.

    Jimmy J.
    United States United States
    • What model motorcycle do you ride? 07 FLSTN
    Easy install

    Just a tip for anyone installing this kit.Put the race insert into the freezer for a few before pressing in.So much easier.Also had an issue with end play.Using the white(smallest) spacer was getting .005".Called baker and told them about this issue,and was told they needed to talk to a engineer about making me a new spacer.Never heard back,so I took off .004" from the white spacer(102") with 120 sandpaper and a flat table.Ended up with .0005" to .001.Other than that install went well.

    Web Product ID: 9847666510
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