• The rear compartment of the left and right engine case halves form the transmission housing or case. An access cover, or trapdoor, is mounted on the left side of the case (inside) behind the primary cover. The main components of the transmission are mounted to this trapdoor to allow you to detach the one cover (together with all the transmission components) for easy removal and servicing without having to split the engine cases in half which otherwise would be a full engine re-build.

• Type - Wet, multiple disc ¹⁾
• Capacity: 174 ft-lbs
• Spring Force/
  • Engaged: 304 lbs
  • Disengaged: 260 lbs
• Clutch shell bearing on clutch gear (loose): 0.0000 in-0.0010 in
• Clutch plate thickness/
  • Drive plate (fiber): 0.150 in ± 0.0031 in
    • Service Limit: 0.130 in (min)
  • Driven plate (steel): 0.0629 in ± 0.002 in
    • Service limit: 0.060 in (min)
• Warp-age (fiber): 0.010 in (max)
• Warp-age (steel): 0.010 in (max)

• Engine sprocket - 34 teeth²⁾
• Clutch sprocket - 59 teeth
• Ratio 1.74:1

• Transmission
  • Mainshaft nut locking screw: 50-60 in-lbs.
  • Mainshaft nut: 35-65 ft-lbs.
  • Engine sprocket nut: 150-165 ft-lbs.
  • Drain plug: 14-21 ft-lbs.
  • Primary cover screws: 80-110 in-lbs.
  • Access cover bolts: 14-19 ft-lbs.
  • Stator Torx nuts: 30-40 in-lbs.
  • Primary chain adjuster nut: 8-12 ft-lbs.
  • Footrest nut: 24-36 ft-lbs.
  • Shift lever pinch-bolt: 90-110 in-lbs.
  • Neutral indicator switch: 3-5 ft-lbs.

• Transmission/ Primary fluid capacity: 1.5 pints³⁾

• Transmission sprocket - 21 teeth⁶⁾
• Rear wheel sprocket - 48 teeth
• Ratio - 2.29:1

1986-90 Evo Sportsters: What every owner should know but were afraid to ask
An __XLForum Thread__ By Four Speed