2023 International MV — Transmission & Axle Gear Ratios

The 2023 International MV is a premier medium-duty truck designed to tackle a wide variety of vocational and delivery applications. Whether you are operating a box truck, a dump truck, a tow truck, or a utility vehicle, the driveline configuration dictates how well the truck performs its specific job. The combination of the Cummins B6.7 or L9 engine with the right transmission and rear axle ratio is critical for balancing startability, cruising speed, fuel economy, and towing capacity.

Below is a comprehensive guide to the transmission and axle gear ratios available for the 2023 International MV Series.

Transmission gear ratios

The 2023 International MV is primarily equipped with Allison fully automatic transmissions, which provide excellent durability and seamless power delivery for medium-duty applications. The most common choices are the Allison 2000 Series (like the 2500 RDS) and the heavier-duty Allison 3000 Series (like the 3000 RDS). Below are the internal gear ratios for these popular 6-speed automatics.

Allison 2500 RDS (Rugged Duty Series) - 6-Speed Automatic

Allison 3000 RDS (Rugged Duty Series) - 6-Speed Automatic

Note: Eaton Fuller manual transmissions and Eaton Cummins Endurant automated manual transmissions (AMTs) are also available via custom factory order, featuring varying 6- to 10-speed ratio steps depending on spec.

Available axle ratios

Because the International MV is highly customizable, it uses commercial axles primarily manufactured by Dana Spicer and Meritor. Axle ratios are selected based on the gross vehicle weight rating (GVWR), tire size, and intended application (highway cruising vs. heavy urban hauling).

How to identify your axle ratio

Unlike light-duty passenger trucks, medium-duty commercial vehicles like the International MV have unique ways of identifying driveline specifications. To find the axle ratio on your MV, use the following methods:

The Line Set Ticket The most accurate way to identify your axle ratio is by locating the Line Set Ticket. Navistar/International places this build sheet inside the cab. Check the inside of the glove box door, the passenger side sun visor, or behind the driver's seat. The Line Set Ticket lists all factory-installed components, including the specific rear axle model (e.g., Dana Spicer S140 or Meritor MS-21-14X) and its exact gear ratio.

The Axle Tag If the Line Set Ticket is missing, you can crawl under the rear of the truck. Dana and Meritor both attach metal identification tags to the differential housing. Typically bolted to the differential cover or stamped directly onto the housing, this tag will display the axle model number and the ratio (e.g., "4.88").

VIN Decoder or Dealer Lookup If the tag is heavily rusted or missing, you can provide your 17-digit Vehicle Identification Number (VIN) to an International Truck dealership or run it through a commercial VIN decoder. This will pull the original factory build sheet.

Towing vs MPG impact

Choosing the correct rear axle ratio is the most important spec decision for a medium-duty truck's total cost of ownership.

Numerically Lower Ratios (e.g., 4.10, 4.33) A lower numerical ratio (often called a "tall" gear) allows the driveshaft to spin fewer times for every rotation of the wheels. This keeps the engine RPMs lower at highway speeds, resulting in better fuel economy and reduced engine wear. These ratios are best suited for dry van box trucks, beverage delivery, or any application where the truck spends most of its time empty or cruising at 65+ mph.

Numerically Higher Ratios (e.g., 4.88, 5.29, 5.57) A higher numerical ratio (a "short" gear) provides greater torque multiplication at the wheels. This dramatically improves low-end pulling power, making it easier to get heavy loads moving from a dead stop without straining the transmission. The trade-off is higher engine RPMs at highway speeds, which decreases fuel efficiency and lowers the vehicle's top speed. These ratios are essential for dump trucks, heavy tow trucks, and vehicles operating primarily in stop-and-go urban environments or off-road job sites.

Common issues

While the driveline components on the 2023 International MV are built for heavy-duty commercial use, vocational abuse and poor maintenance can lead to premature wear.

• Pinion Seal Leaks: Continuous hauling of heavy payloads can cause heat buildup in the differential, leading to pinion seal degradation and gear oil leaks.
• Ring and Pinion Whine: If the truck is frequently overloaded beyond its GCWR, the gears can suffer from improper meshing, leading to an audible whine during acceleration or deceleration.
• Carrier Bearing Wear: In vehicles with long wheelbases and multi-piece driveshafts, the carrier bearings take a beating. Shuddering or vibrations upon takeoff usually point to a worn carrier bearing or U-joint rather than the axle itself.
• Contaminated Differential Fluid: Vocational trucks working in dirt, mud, or high water can ingest debris through the axle breather tube, breaking down the gear oil and rapidly destroying the differential bearings.

Find a driveline shop on Repairius. Ensure your medium-duty truck stays on the road and making money by connecting with top-rated commercial driveline specialists in your area today.