Since 1945, Muncie has delivered the muscle behind America’s most iconic transmissions. Today, AutoGear continues that legacy—engineered for modern power with vintage soul.

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2-Speed Series

New & Improved

AutoGear 2-Speed Series transmission

Classic wide-ratio performance, re-engineered with modern durability.

  • Laser-cut side-cover detents
  • N-Series 40-spline mainshaft
  • 15 ratio configurations with 27 or 32-spline outputs
  • Modular, serviceable cluster assembly

AUTOGEAR M20

The Wide-Ratio Street Classic

AutoGear M20 transmission

Wide-ratio gearing for smooth street performance and relaxed cruising.

  • 1st Gear: 2.52:1
  • Input: 10 or 26 spline
  • Output: 27 or 32 spline
  • Known for its larger 29-tooth countergear

AUTOGEAR M22

“Rock Crusher”

AutoGear M22 Rock Crusher transmission

Straight-cut gears and legendary strength for high-torque muscle-car builds.

  • 1st Gear: 2.20:1
  • Input: 26 spline
  • Output: 32 spline
  • 27-tooth straight-cut countergear

AUTOGEAR M23

Modernized Muscle

AutoGear M23 transmission

Modern materials and fast, controlled shifts for serious street and track builds.

  • Multiple ratio codes: Z, X and W
  • SCCA-approved options available
  • Ultracase standard for added durability
  • Designed for high-rpm performance and endurance

Assembly Matrix

Manual Transmission Gears Parts 2025
Manual Transmission Gear Parts Assembly Matrix

Detailed overview of assemblies, gear compatibility, spline types, and roller configurations.

Ratio Chart

AutoGear Gearbox & Gearset Option Codes
AutoGear Ratio Codes Guide

Instantly access input and output spline, roller, and ratio data for the M20, M22, and M23 Series.

Getting you the right gearbox

Looking for a new Four-Speed or Muncie Gearset?

Our EZ Spec configuration form will help submit your inquiry for one of our gearsets.

EZ Spec Form

or send us a message

What Makes a Muncie a Muncie?

Model 1st Gear Input Spline Countershaft Teeth Known For
M20 2.52 10 or 26 29 or 25 Street-friendly, wide-ratio
M22 2.20 26 27 (straight-cut) Rock Crusher strength
M23 Variable 26 Various Modern refinement + Ultracase

As Featured On

Testimonials

"Amazing…truly amazing. It is the more than I had hoped for and I could not be happier. Diane and I enjoy riding around and showing off the car."

Louis

"AutoGear did a great job in helping me decide the best gearbox for my ‘73 Camaro. It came in a week and it did just what Nate said it would do"

Customer

"I appreciate your honesty and integrity.  Sometimes as you well know things don't work out the way we would want them to. But we have pushed through and made things right. And again, I appreciate you working through this process, and Nathan too, can't forget about giving him props.  Very knowledgeable guy and an asset to Autogear."

Rick

"Conclusion of the race week end is quite good, we had issue with a slippery clutch.. so I already took contact with mike Norcia from Ram as you suggested to us."

Customer

"Me and my customer are very happy of your product,  we would like to thank you for the rapidity and the way you helped us to get ready in time."

Customer