Transmission Component

Transmission inspector

Mandatory powertrain component that handles gear ratios, shifting logic, and power transmission from engine to differential/wheels. Always third in the Powertrain.Components list.

Gearing

  • Gearing is assigned through the gears list ordered from reverse (negative), neutral (0), then forward gears (positive).
  • Example: {-2.216, 0, 3.274, 2.093, 1.439, 1.084, 0.817, 0.651} = 1 reverse + neutral + 6 forward gears
  • finalGearRatio multiplies each gear ratio, equivalent to axle/differential ratio (typically 3-6 for cars, higher for trucks).
  • Gear ratios can be adjusted at runtime.

Transmission Types

Transmission types

Manual

Gears can only be changed through user input. Check Input Setup for input bindings.

Additional Settings:

  • holdToKeepInGear - If enabled, gear input must be held continuously (for hardware H-shifters). Releasing input returns to neutral.
  • ignorePostShiftBanInManual - When enabled (default), manual shifts are instant without post-shift ban delay.

Automatic

Vehicle shifts automatically based on:

  • Upshift RPM / Downshift RPM - Base shift points
  • Variable Shift Point - When enabled, adjusts shift points based on throttle position and incline
  • Variable Shift Intensity - How much throttle affects shift points (0-1)
  • Incline Effect Coeff - Delays upshifts on steep inclines to prevent lugging

Shift Behavior:

  • isSequential - Only allows shifting one gear at a time (e.g., 3rd to 4th only)
  • allowUpshiftGearSkipping - Allows skipping gears during upshift (e.g., 2nd to 4th) when not sequential
  • allowDownshiftGearSkipping - Allows skipping gears during downshift (e.g., 5th to 2nd) when not sequential

D/N/R Shifting:

  • automaticTransmissionDNRShiftType:
    • Auto - Automatically shifts to Drive on throttle, Reverse on brake
    • RequireShiftInput - Requires explicit shift input to change D/N/R
    • RepeatInput - Input must be released then re-applied to shift
  • dnrSpeedThreshold - Maximum speed for D/N/R transitions (default 0.4 m/s)

CVT

Continuously Variable Transmission provides smooth, stepless ratio changes. Maintains engine RPM at an optimal point based on throttle and vehicle speed. No discrete gear shifts, only D/N/R transitions.

Gears List Format:

Requires minimum 4 entries:

{ -2.5, 0, 2.5, 0.5 }
   │    │   │    └── Min ratio (overdrive) - high speed cruising
   │    │   └─────── Max ratio (low gear) - launch/acceleration
   │    └─────────── Neutral
   └───────────────── Reverse

CVT Settings:

  • cvtTargetRPMPercent (0.3 - 0.9) - Target engine RPM as percentage between idle and rev limiter. Lower = efficiency, higher = performance.
  • cvtResponseRate (1 - 20) - How quickly ratio adjusts. Higher = faster response.
  • automaticTransmissionDNRShiftType - Same as Automatic transmission (see above)
  • dnrSpeedThreshold - Same as Automatic transmission (see above)

CVT Behavior:

Condition Behavior
Standstill + throttle Max ratio (high torque) for launch
Accelerating Ratio decreases to maintain target RPM
Cruising Ratio approaches min (overdrive) for efficiency
High throttle Target RPM increases, ratio adjusts accordingly
Coasting (throttle off) Ratio holds for consistent engine braking
Stopping Shifts to neutral below speed threshold

External

Custom shifting logic via delegate assignment. Assign shiftDelegate to implement your own shift pattern. If delegate is not assigned, no gear shifts will occur.

Timing

  • shiftDuration - Time to change gears. Engine throttle is cut during shift. Applies to all transmission types.
  • postShiftBan - Minimum time between shifts. Prevents gear hunting. Only affects automatic transmissions (ignored in manual when ignorePostShiftBanInManual is enabled).
  • shiftInAir - Whether transmission can shift when all wheels are off the ground.
  • shiftProgress - Read-only (0-1) showing current shift progress during gear change.

Additional Features

Clutch Integration:

  • clutchInputShiftThreshold - If >0, clutch must be released below this value for shifts to occur.
  • triedToShiftWithoutClutch - UnityEvent triggered when player attempts to shift without clutch pressed.

Events:

  • onShift - Triggered on any gear change (up or down)
  • onUpshift - Triggered when shifting to higher gear
  • onDownshift - Triggered when shifting to lower gear

Properties:

  • Gear - Current gear number (-1 = R, 0 = N, 1+ = forward gears)
  • GearName - Formatted gear name as string (e.g., "R1", "R2", "N", "1")
  • currentGearRatio - Current total gear ratio (gear × finalGearRatio)
  • ShiftInto(int gear) - Method to shift into specific gear programmatically