Baker Drivetrain N1 Replacement Shift System

Baker Drivetrain 4-Speed N1 Shift Drum Kit

PN 4-155N1-K (N1 Shift Drum Kit For Ratchet Style Top Covers)

Features

Tired of stalling your jockey shift bike while trying to find neutral? Just imagine as you roll up to the stoplight, you tap all the way forward with your left hand and you are guaranteed neutral because it is the last stop on the shift pattern. Little Suzie notices your skill in negotiating your bike to a seamless stop and decides to hop on and leave her boyfriend. The BAKER N1 Shift Drum Kit was designed for the jockey shifter in mind. The kit comes with everything you would need to change your stock shifting 4-Speed into a jockey/hand shift bike; does not come with a jockey shift lever.

Shift Pattern

N1 Drums were originally developed to prevent miss shifts between 1^st and 2^nd by positioning neutral at the bottom, under 1^st. This drag racer trick also eliminates all room for error in finding neutral on a jockey shift bike. The N1 Shift Drum Pattern is N-1-2-3-4; with neutral being in the most forward position when using a hand shift lever. If you are using this kit on forward controls (bottom pull, FL models) the shift pattern would be reversed (reverse shift pattern; 4-3-2-1-N). All the way up on the shift lever would be neutral and all the way down would be 4^th gear.

Fitment

• 1952-79 4-Speed Ratchet Style Top Covers

Tools Required

• Torque Wrench (reads both in. lbs. and ft. lbs.)
• Common Hand Tools (Allen Wrenches, Sockets, Snap Ring Pliers, Etc.)
• Fork Shifter Gauge
  • H-D® P/N 96384-39
  • JIMS® P/N 16-0641

Specifications

• TRANSMISSION FLUID CAPACITY: 20-22 fluid oz. BAKER Recommends: Spectro™ Heavy Duty Platinum 6 Speed Transmission Oil, P/N BD-75140
• SHIFT DRUM END PLAY: .0005”-.0065”
• 1^ST And 2^ND Gear Shift Fork Dog Tooth Gap Clearance: .080”-.090” (Both Sides)
• 3^rd And 4^th Gear Shift Fork Dog Tooth Gap Clearance: .100”-.110” (Both Sides)

4-Speed N1 ShiftDrum Kit Detail View

Figure 1.

1) Remove the transmission from the motorcycle chassis per your Factory Service Manual. 2) Remove the 12 screws securing the top cover to the transmission, 2 of these screws are about 2” in length located next to the ratchet assembly.

Figure 2; Cam Follower

3) Disassemble the top cover per your Factory Service Manual. 4) Clean all parts except, shift shaft, shifter gear, and drum using grease solvent or equivalent. You will not be reusing the old shaft, gear and drum. Polish both sides of the detent cam follower with a scotch bright pad or equivalent and a hand held drill (cordless preferred) see Figure 2; this will aid in smooth shifting.

Figure 3; Bushing inspection

5) Inspect fitment of new Ratchet Shaft (pn 160N1-4) in the top cover bushing; per your Factory Service Manual replace bushing if necessary; reference Figure 3. 6) Inspect all components per your Factory Service Manual and replace worn or out of specification parts if necessary.

Figure 4; Shaft Gear Aligment

Installation:

1) Re-using the ratchet gear spring; install the new ratchet gear (pn 138N1-4) and old spring into the top cover, so that the counter bore of the gear is facing the backing plate gasket surface. 2) Install the ratchet shaft (pn 160N1-4) supplied in the kit by lining up the timing mark on the gear (painted white) with the edge of the shaft tooth as shown in figure 4. Using a screw driver hold the spring loaded gear toward the backing plate surface and install supplied cotter pin (pn 9R100PCO0P) and bend over (Figure 5).

Figure 5; Cotter Pin Install

3) Install the N1 Shift Drum (pn 127SN1-4) in the cover so the timing mark on the top of the tooth (shorter tooth/painted white) lines up with the timing mark on the ratchet gear (Figure 6). Apply some transmission oil to the drum rod O-ring and rod; install the rod so that the seal side is facing toward the detent end of the top cover. Install the drum rod retaining screw per your Factory Service Manual. Check to make sure shift drum spins freely with no binding. 4) Install the cam follower making sure the end of the cam follower lands into the detent of the shift drum (Figure 7) and install the neutral switch per your Factory Service Manual.

Figure 6; Drum Timing

5) Position the top cover so that the Ratchet Shaft is facing upward; Place the supplied gasket (pn 155-4GAS) onto the top cover and install the Adapter (backing) Plate per your Factory Service Manual. 6) Time the Ratchet Shaft to the Backing Plate following your Factory Service Manual making sure that the timing mark notch on the backing plate aligns exactly between the two shifter teeth while in gear (Figure 8). Tighten screw with washer to 6-9 ft-lbs (100-110 in-lbs) 7) Following your Factory Service Manual reinstall all ratchet springs, carrier, pawls etc. along with the supplied Ratchet Cover Gasket (pn 158-4GAS). Use Blue Loctite® on all top cover screws; tighten per your Factory Service Manual.

Figure 7; Cam Follower

8) Install dust cover/shield and lever per your Factory Service Manual. 9) Check the shift fork dog tooth gap by using the Fork Shifter Gauge; H-D®P/N 96384-39 or equivalent following your Factory Service Manual. Shim shift forks if necessary to get proper dog tooth gaps following your Factory Service Manual.

Figure 8; Backing Plate Timing

10) Reinstall your top cover assembly using the supplied top cover gasket (pn 156-4GAS) and using Blue Loctite® on the top cover screws. Install per your Factory Service Manual making sure that the Vented Screw removed (2nd step under Prep) is reinstalled in it original position.

11) While the transmission is still on the bench; do a shift check through all the gears to make sure that it is functioning properly.

12) Reinstall your transmission assembly following your Factory Service Manual.

13) Installation is complete; make sure to add the proper fluids following your Factory Service Manual and check fluid levels after initial test ride.