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Tin Type Primary

  • Billet 6061-T6 aluminum inner and outer primary housings available in steel shot blasted or show polished finish
  • Available in kick only and 1.4kw 1990-2006 style starter configuration
  • Starter type includes jackshaft and related hardware
  • Modern fine chain tooth adjuster shoe and L-bracket included
  • O-ring sealed locking flanged nuts for transmission-to-inner primary studs
  • Nostalgic slotted screws, gasket and related hardware included
  • Zero leak drain plug with magnet standard
  • Chain oiler and suction hardware included
  • Inner primary is reinforced for strength around the mainshaft bore
  • Works with stock style derby and inspection covers
  • 2-Year limited warranty



  • Quiet: Reduces chain noise
  • Modern: Modern starter integration possible
  • Clean: With redesigned parts, we have made sure that our TTP, leaks much less than the original
  • Wet or Dry: Can be run dry with Shovelhead era clutches and a 1970-E84 4-speed


  • 1970-E84 Big Twins and custom 4-speed builds
  • 1970-79 ratchet top 4-speeds (top or bottom pull)
  • 1980-E84 turtle top 4-speeds (non starter TTP version only)
  • Jockey top 4-speeds
  • BAKER 4-speed & BAKER 6-into-4


    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.

    Questions? Ask us anything:
    Contact us
    Or just call us at 517-339-3835. We're glad to help.

    Tin Type Primary
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    Tin Type Primary Tin Type Primary Tin Type Primary Tin Type Primary Tin Type Primary Tin Type Primary Tin Type Primary Tin Type Primary
    Baker Drivetrain Team Illustration