Drivetrain› Manual Transmissions and Components

AutoGear

M22 Rock Crusher 4-Speed Manual Transmission

$3,499.00

SKU: 0566548

Special Order
Special Order
Ships in 4–6 weeks
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Advanced — 4+ hours

Overview

The Auto Gear M22 Rock Crusher is a 4-speed manual transmission designed as a performance replacement. It features an upgraded ultra case for enhanced strength and is available in wide or close ratios. This heavy-duty transmission is built to withstand high horsepower applications.
Show original supplier description
The Auto Gear Upgraded Ultra Case M22 Rock Crusher 4-speed transmission is engineered as a direct performance replacement for classic GM vehicles. It boasts a new Muncie Auto Gear ultra case, making it one of the strongest M22 transmissions available, designed to handle significant horsepower. This heavy-duty Rock Crusher is available in either Wide (2.56-1st, 1.75-2nd, 1.36-3rd, 1:1-4th) or Close (2.20-1st, 1.64-2nd, 1.27-3rd, 1.00-4th) ratios, making it ideal for use with rear-end gears ranging from 3.42 to 4.88. The transmission features a C355 forged aluminum mid-plate, an AG side cover, and a super tail housing with either a 27 or 32 spline output shaft, including a passenger-side speedometer connection. It is a professionally built Muncie unit with zero miles since assembly. Designed for a direct fit, this M22 transmission eliminates the need for extensive modifications often associated with installing 5 or 6-speed transmissions. It is compatible with all 1963-1974 GM cars requiring a 10 or 26 spline clutch disk. The transmission also includes fill and drain plugs for ease of maintenance. Customers have praised its smooth action, performance, and characteristic M22 gear whine.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

Fitment Guaranteed

Don’t gamble
on fit.

Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

Available on iOS & Android

Specifications

BrandAutoGear
Part Number0566548
CategoryDrivetrain
5,000+ Trusted brands
1M+ Enthusiasts
5M+ Parts sold
(760) 282-4645 hello@motormia.co

Buy with Confidence

Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

View Full Return Policy

Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

View Full Shipping Policy