Forged Countershaft Cluster Gear & Bearings
One-piece forged lower layshaft carrying four integral helical gears that spins whenever the clutch is engaged.
Role in the System
What This Assembly Is
Positioned exactly 84.50 mm below the mainshaft centerline is the one-piece forged steel countershaft cluster gear, supported at the front wall by a cylindrical roller bearing and at the center bulkhead by a shielded ball bearing.
Mechanics & Physics
How the Subcomponents Work Together
Always-Meshed Torque Counter-Drop: The 37-tooth front head gear of the countershaft is in permanent mesh with the 24-tooth input shaft gear. Whenever the engine is running and the clutch pedal is up, the countershaft cluster spins in the opposite direction at 64.9% of engine RPM—simultaneously driving the 3rd (31T), 2nd (24T), and 1st (15T) speed gears above it.
Other Assemblies in This System
M5OD-R2 Aluminum Main Case, Bellhousing & Extension
One-piece rib-reinforced die-cast aluminum bellhousing and gearbox case with internal splash-lubrication gutters.
Input Shaft, Output Mainshaft & Pocket Bearings
Two coaxial shafts sharing the exact same upper centerline—coupled through a hollow pocket needle bearing.
1st–5th Helical Speed Gears, Needle Bearings & Reverse Idler
Constant-mesh helical speed gears that freewheel on split needle roller bearings until locked by a synchronizer.
1–2, 3–4 & 5th–Reverse Borg-Warner Synchronizers
Miniature brass cone clutches and splined dog sleeves that match shaft speeds in milliseconds for clash-free shifting.
Top Shift Cover, 3-Rail Interlocks, Forks & Lockout Cam
Three parallel shift rails and hardened transverse interlock pins that make selecting two gears at once physically impossible.
Floor Shifter Tower, Lever & Transmission Switches
Direct-turret floor shifter lever, pivot ball bushings, backup lamp switch, neutral sense switch, and VSS drive.