BAKER Drivetrain Four Speed Left Side Drive Complete Transmission for 1936-1984 Panhead, Knucklehead, and Shovelhead Harley-Davidson Motorcycles

The introduction of the Knucklehead and the 4-speed in 1936 marked an epoch in the history of American motorcycles. Many consider the period of 1936-1984 the holy grail of Harley-Davidson. To carry on that legacy, BAKER developed the BAKER 4-speed, available with ratchet top or jockey top lids. Favored by those inspired by the old school cool, garage builders and riders of the nostalgic persuasion this transmission offers the worry-free convenience and reliability of a new BAKER Drivetrain product. The external architecture of our cast (A356-T6) 4-speed transmission case was modeled after factory cases to capture all the details and character of the original design.

BAKER made many functional upgrades to address shortcomings of the original design like leaks, serviceability, and durability. The loose rollers on the maindrive gear were replaced with a radial ball bearing. The bronze bushings on the gearset were replaced with caged needle bearings. BAKER added a provision, hidden in the back of the case, for an electronic speedo but retained the traditional worm gear speedo provision on the front of the case. The stock Fred Flintstone shift detent was replaced with a snot-slick linear ball bearing detent for that smooth ‘snick-pop’ shift quality you expect from BAKER.

Shift System: We manufacture three shift drums for the 4-speed; the FX & FL types with conventional shift patterns and the N1 style. The N1 drum takes the FX pattern and relocates neutral down below 1st for a N-1-2-3-4 pattern as an alternative to the standard 1-N-2-3-4 pattern. Great for foot clutch and performance applications.

Shift Lever Orientation: The FL shift drum in a Jockey top cover is setup for a top pull (1936-46) or bottom pull (1947-65). The N1 shift drum in a Jockey top cover is setup for bottom pull only. The FL shift drum in a Ratchet top cover is bottom pull only. The FX and N1 shift drum in a Ratchet top cover is top pull only.


  • 1936 to 1984 Knucklehead, Panhead or Shovelhead Harley-Davidson motorcycles.
  • 1936 to 1964 tapered mainshaft.
  • 1965 to 1969 tapered mainshaft.
  • 1970 to early 1984 tapered or splined mainshaft.

  • Available finishes are raw blasted, wrinkle black, or show polished (add $250).
  • Vintage sand cast (A356-T6) design that holds true to the original 1936 through mid-1980’s.
  • Hidden transmission vent designed into the Ratchet and Jockey Top covers.
  • Billet steel machined and case hardened shift systems (FL, FX and N1) that rotate on Permaglide bushings for a smooth, repeatable shift each time; see technical section.
  • BAKER Klassic Gears come standard.
  • Modern 4-speed gearset made out of 8620 gear steel.
  • Gears ride on needle bearings, not bronze bushings.
  • Vintage cast kicker cover with traditional 1 piece release rod and BAKER Heavy Duty throwout bearing.
  • Direct bolt-in on most models; see technical section for instructions and 1965-1969 fitment (ear case).
  • Backed by a 5 year manufacturer's limited warranty from BAKER Drivetrain.


BAKER Builder's Kits come fully assembled
and ready to install into your existing
transmission case with no modifications,
shimming, or adjustments required.