2018 International MV Transmission Fluid & Service Guide

Maintaining the transmission in your 2018 International MV is crucial for its longevity and reliable performance. This guide provides detailed information on transmission fluid type, capacity, filter, and service intervals, as well as common issues to watch out for.

Quick Answer

• Transmission Make/Model: Eaton Fuller FSO-6406A (most common in 2018 MV series, always verify your specific truck's transmission tag)
• OEM Fluid Spec: Eaton PS-278 Synthetic Transmission Fluid (or equivalent meeting the PS-278 specification)
• Drain & Fill Capacity: Approximately 11-13 quarts (verify with dipstick and service manual)
• Full Overhaul Capacity: Approximately 13-15 quarts (verify with service manual)
• Filter OEM Part Number: No external filter for Eaton Fuller FSO series manual transmissions (internal screen/magnet system).
• Recommended Service Interval: 100,000 to 250,000 miles or 24-48 months, depending on application and duty cycle.

Fluid Type Explained

The most common transmission found in the 2018 International MV series, particularly for medium-duty applications, is the Eaton Fuller FSO-6406A 6-speed manual transmission. These transmissions require a high-quality synthetic transmission fluid that meets or exceeds the Eaton PS-278 specification. This specification ensures the fluid provides excellent thermal stability, wear protection, and shifting performance under various operating conditions.

Using a fluid that does not meet the PS-278 specification can lead to premature wear of internal components, difficult shifting, reduced fuel economy, and potential transmission failure. Always consult your truck's owner's manual or the transmission service manual to confirm the exact fluid requirements for your specific transmission model.

Service Procedure

Eaton Fuller manual transmissions like the FSO-6406A typically do not have an external serviceable filter. Instead, they often utilize internal screens and magnets to capture metallic debris. Therefore, service primarily involves draining and refilling the transmission fluid.

Drain & Fill Procedure:

1. Preparation: Park the truck on a level surface and engage the parking brake. Allow the transmission to cool down, but it should still be warm enough for the fluid to drain easily. Place a large drain pan beneath the transmission drain plug.
2. Drain Fluid: Locate and remove the drain plug, allowing all the old fluid to drain completely. Inspect the drain plug for any metallic particles, which could indicate internal wear.
3. Clean/Inspect: If your transmission has an accessible magnetic drain plug, clean off any accumulated metal shavings. Reinstall the drain plug securely.
4. Refill Fluid: Locate the fill plug. Using a fluid pump, slowly add the new Eaton PS-278 compliant synthetic transmission fluid until it reaches the bottom of the fill hole. Some transmissions have a dipstick; in this case, fill to the "FULL" mark on the dipstick.
5. Check Level: After refilling, operate the transmission through all gears briefly, then recheck the fluid level and top off if necessary.

Full Exchange (Overhaul): A full exchange typically occurs during a transmission overhaul or rebuild, where the entire unit is disassembled, cleaned, and refilled with new fluid. In a standard service, a simple drain and fill is the prescribed method for manual transmissions.

Service Interval

The recommended service interval for the transmission fluid in a 2018 International MV with an Eaton Fuller FSO-6406A can vary significantly based on operating conditions:

• Normal Duty: For light-duty applications, highway cruising, and minimal towing, a service interval of 200,000 to 250,000 miles or 48 months is often recommended.
• Severe Duty/Towing: Trucks engaged in heavy hauling, frequent stop-and-go driving, off-road use, or operating in extreme temperatures should have their transmission fluid serviced more frequently. A severe duty interval could be as low as 100,000 to 150,000 miles or 24-36 months.

Always refer to your International MV's owner's manual for the most accurate and up-to-date service schedule for your specific vehicle and duty cycle. Regular fluid analysis can also help determine the optimal change interval.

Common Transmission Problems for this Generation

While Eaton Fuller manual transmissions are known for their robustness, certain issues can arise in the 2018 International MV generation:

• Hard Shifting/Gear Engagement Issues: This can often be attributed to low or incorrect transmission fluid, worn clutch components, or issues with the shift linkage. Worn synchronizers can also cause grinding during shifts.
• Noise from Transmission: Whining, grinding, or clunking noises can indicate worn gears, bearings, or other internal components. Addressing these noises early can prevent more significant damage.
• Fluid Leaks: Seals and gaskets can degrade over time, leading to fluid leaks. Inspecting the transmission regularly for signs of leakage can help prevent low fluid levels and consequent damage.
• Difficulty Getting Into Gear: Beyond fluid issues, this could point to problems with the clutch, clutch master/slave cylinders, or internal transmission issues like worn detents.
• Premature Wear Due to Incorrect Fluid: As mentioned, using non-compliant fluid can accelerate wear on gears, synchronizers, and bearings, leading to premature failure.

Regular inspections, adherence to service schedules, and using the correct fluids are your best defense against these common problems.

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