2018 International MV Transmission & Axle Gear Ratios

The 2018 International MV is a highly versatile medium-duty truck trusted by delivery fleets, municipalities, and towing companies. Configuring the right powertrain is critical for medium-duty applications, as the interplay between transmission gearing and rear axle ratios determines whether the truck excels at highway cruising, heavy hauling, or urban stop-and-go driving. Below is a comprehensive guide to the transmission and axle gear ratios available for the 2018 International MV.

Transmission gear ratios

The 2018 International MV is typically equipped with a Cummins B6.7 or L9 engine, paired primarily with Allison automatic transmissions, though Eaton Fuller automated manuals are also common. Below are the gear ratios for the most popular Allison and Eaton transmissions found in this chassis.

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

Allison 3000 RDS 6-Speed Automatic

Eaton Procision 7-Speed Dual-Clutch Transmission

Available axle ratios

Because the International MV serves a wide array of industries—from box trucks to dump trucks and tow trucks—Dana Spicer and Meritor supply a vast range of rear axle ratios.

How to identify your axle ratio

Identifying the exact axle ratio on a medium-duty truck like the 2018 International MV is straightforward if you know where to look:

• Door-Jamb Line Setting Ticket: Unlike passenger vehicles with simple RPO codes, International trucks use a "Line Setting Ticket" (LST) or build sheet, often found inside the driver's door jamb, inside the glove compartment, or behind the sun visor. This document lists all factory-installed components, including the rear axle make, model (e.g., Dana Spicer S140 or Meritor MS-21-14X), and the specific gear ratio.
• Axle Tag: Crawl under the rear of the truck and look at the differential housing. Most Dana and Meritor axles have a metal identification tag bolted to the differential cover or stamped into the housing itself. This tag will display the gear ratio (e.g., "4.10" or "41-10", meaning a 41-tooth ring gear and a 10-tooth pinion).
• VIN Decoder: Your local International truck dealer can run your Vehicle Identification Number (VIN) through their service portal to pull the exact factory specifications, including the driveline configuration.

Towing vs MPG impact

The relationship between your rear axle ratio, towing capabilities, and fuel efficiency is one of the most critical factors in setting up a commercial truck.

• Numerically Lower Ratios (e.g., 3.73, 4.10): These are often referred to as "tall" gears. They allow the engine to run at lower RPMs at highway speeds, resulting in better fuel economy. However, they provide less wheel torque for getting heavy loads moving off the line, making them ideal for lighter dry vans or trucks that spend all day on the interstate.
• Numerically Higher Ratios (e.g., 4.63, 4.88, 5.29): Known as "short" gears, these provide massive torque multiplication. This is essential for tow trucks, dump trucks, and fully loaded vocational vehicles that need aggressive low-end grunt to accelerate. The trade-off is reduced top speed and significantly worse fuel economy, as the engine must spin at a higher RPM to maintain highway speeds.

Common issues

While the driveline components in the 2018 International MV are built for severe duty, high mileage and heavy payloads can eventually take their toll:

• Ring & Pinion Whine: Incorrect backlash settings or prolonged heavy hauling with low gear oil can cause accelerated wear on the ring and pinion teeth, resulting in a distinct whine that changes pitch under acceleration or deceleration.
• Carrier Bearing Wear: The heavy, multi-piece driveshafts used on these long-wheelbase trucks rely on carrier bearings. If these bearings fail or the rubber isolators tear, you will feel a prominent vibration through the floorboards and steering wheel, especially at lower speeds or when taking off with a heavy load.
• Leaking Pinion Seals: Commercial use often leads to pinion seal wear. If you notice gear oil weeping from the front of the differential where the driveshaft connects, the seal needs to be replaced before the fluid gets dangerously low.
• Limited-Slip / Locker Wear: If equipped with a locking differential or heavy-duty limited-slip, the clutch packs or locking mechanisms can wear out, causing chatter around corners or a failure to engage in low-traction environments.

If you are experiencing vibrations, differential whine, or need to re-gear your truck for a different application, professional service is highly recommended. Find a driveline shop on Repairius to keep your International MV fleet running smoothly.