Frequently Asked Questions About International LT Drivetrain Parts
What drivetrain components are compatible with my International LT model year?
International LT drivetrain parts compatibility varies by model year and configuration. For 2017-2019 models, most standard Eaton Fuller transmissions (13-speed and 18-speed) and Meritor differentials are direct replacements. 2020 and newer models may have updated spline counts and mounting patterns. Always verify your specific OEM and component serial numbers before ordering, as International offered multiple drivetrain configurations within the same model year. Manual transmission models typically use SAE standard clutches, while automated models require specific Eaton or Allison components.
How difficult is it to replace U-joints and carrier bearings on an International LT?
U-joint replacement on International LT trucks requires moderate mechanical skill and proper tools. Most drivers report 2-4 hours for a complete driveshaft U-joint replacement when using a proper U-joint press. Carrier bearing replacement is more involved, typically requiring driveshaft removal and rebalancing. Common challenges include seized U-joint caps due to road salt exposure and difficulty accessing the forward joints on shorter wheelbase models. Having a transmission jack or helper is strongly recommended for driveshaft removal, as these components can weigh 80-150 pounds depending on length.
What are the signs that my International LT differential needs rebuilt or replaced?
Common indicators include whining noise that changes with speed (worn ring and pinion), clunking during acceleration or deceleration (excessive backlash), and gear oil leaks around the pinion seal or axle tubes. International LT differentials typically show wear between 400,000-600,000 miles under normal highway use. Heavy vocational use or frequent overloading can reduce this to 250,000-350,000 miles. Check differential fluid every oil change - metal shavings or a burnt smell indicate immediate attention needed. Most LT models use Meritor differentials with readily available rebuild kits.
Which clutch brands work best for International LT manual transmissions?
Eaton, Sachs, and Valeo clutches are the most reliable options for International LT manual transmissions. For standard highway applications, organic clutches provide smooth engagement and typically last 400,000-500,000 miles. Ceramic clutches are recommended for heavy haul or vocational use but require more careful engagement to prevent drivetrain shock. The LT uses standard 15.5-inch or 14-inch clutches depending on transmission model. Avoid economy brands that may not maintain proper clamp load, leading to premature wear and potential flywheel damage.
Can I upgrade my International LT transmission from manual to automated?
Converting from manual to automated transmission is technically possible but requires extensive modifications. The upgrade typically costs $15,000-$25,000 including parts and labor. You'll need a compatible Eaton Endurant or Fuller Advantage transmission, new ECM programming, dashboard switch panels, wiring harnesses, and potentially a different driveshaft length. Most technicians recommend purchasing a truck already equipped with an automated transmission rather than converting, as the complexity often leads to ongoing electronic issues. If pursuing conversion, use only certified International or Eaton dealers to maintain warranty coverage.
