Muncie M22 Gearbox

‘Syracuse’ M22: The Rock Crusher, Reimagined

The original Muncie M22 earned its “Rock Crusher” nickname for the high-pitched whine of its straight-cut gears. That sound came from speed-over-quality, back when low-cost Detroit assembly was king.

But your build deserves better.

The ‘Syracuse’ M22 is a modern evolution — engineered for power, precision, and longevity. We redesigned the gear profiles to run quieter, cooler, and stronger — while keeping that legendary performance heritage intact.

Available Gear Ratios

 

Model 1st Gear 2nd Gear 3rd Gear 4th Gear Best For
M22 2.20 1.64 1.27 1.00 3.73+ rear gears
M22W 2.56 1.75 1.36 1.00 3.42–4.11 gears
M22Z 2.98 2.04 1.46 1.00 3.08–3.36 gears

All versions deliver the straight-cut strength M22s are known for — but with AutoGear’s exclusive engineering to improve durability and shifting feel.

What You Get with Every ‘Syracuse’ M22

– ✅ Muncie-compatible footprint – Reuse your clutch, shifter, and driveshaft
– ✅ Masiero Italian gears – Legendary strength, made for serious loads
– ✅ N-Series Supercase + mainshaft – Rigid, vibration-resistant aluminum housing
– ✅ Controlled-clearance synchronizers – Fast, reliable shifts under stress
– ✅ Kyowa rings – The strongest, most precise synchros available
– ✅ U.S.-cast housings & plates – Machined in-house with aircraft-grade aluminum

Customization Options

  • – Input Spline: 10- or 26-spline
  • – Output Shaft: 27- or 32-spline
  • – First Gear: AutoGear “Roller 1st” or grooved bushing
  • – Speedometer Gear: 7- or 8-tooth (passenger side only)

Built for Power

Engineered for vintage musclecars, hot rods, and resto builds pushing up to ~500hp/tq, the ‘Syracuse’ M22 delivers straight-cut strength and unmistakable sound.

With upgraded materials and precision gear profiles, this Rock Crusher runs cooler and quieter than the original—without sacrificing heritage performance.

Need help choosing the right ratio or setup? Contact us for a personalized recommendation.

Muncie Gearbox Comparison

Model Strength Shift Feel Best For Details
Muncie M20 Smoothest Easiest to drive Street cruising & lighter loads Wide ratio, ideal for new drivers
Muncie M22 Strong & mechanical “Syracuse whine” Musclecars & resto builds Straight-cut Rock Crusher heritage
Muncie M23 Fast & modern Quickest shifts Track & street & torque builds Modern materials in classic case

Resources

View documents and resources related to this gearbox in the resource center.