2019 International LT: Transmission & Axle Gear Ratios
AI-generated reference. Always verify torque values, fluid capacities, intervals, and procedures against the manufacturer's service manual or OEM repair information before performing work. Repairius is not liable for damage from acting on this content without verification.
Working on this 2019 International LT? Run just this one job through Repairius.
No big switch. Write the estimate, text it for approval, and get paid on your phone. Keep everything else the way it is.
14-day free trial · credit card required · cancel anytime
Transmission Gear Ratios
The 2019 International LT was available with a wide array of transmissions from Eaton and Allison.
Eaton Endurant
| Gear | Ratio |
|---|---|
| 1 | 14.43 |
| 2 | 11.28 |
| 3 | 8.81 |
| 4 | 6.89 |
| 5 | 5.38 |
| 6 | 4.21 |
| 7 | 3.29 |
| 8 | 2.57 |
| 9 | 2.01 |
| 10 | 1.57 |
| 11 | 1.23 |
| 12 | 1.00 |
| Reverse | 17.02 |
Eaton Fuller (Manual)
10-Speed
| Gear | Ratio |
|---|---|
| 1 | 14.72 |
| 2 | 11.02 |
| 3 | 8.18 |
| 4 | 6.05 |
| 5 | 4.45 |
| 6 | 3.30 |
| 7 | 2.45 |
| 8 | 1.81 |
| 9 | 1.34 |
| 10 | 1.00 |
| Reverse | 15.39 |
18-Speed
| Gear | Ratio |
|---|---|
| 1 | 14.40 |
| 2 | 12.29 |
| 3 | 8.51 |
| 4 | 7.26 |
| 5 | 6.05 |
| 6 | 5.16 |
| 7 | 4.38 |
| 8 | 3.74 |
| 9 | 3.20 |
| 10 | 2.73 |
| 11 | 2.29 |
| 12 | 1.95 |
| 13 | 1.62 |
| 14 | 1.38 |
| 15 | 1.17 |
| 16 | 1.00 |
| 17 | 0.86 |
| 18 | 0.73 |
| Reverse | 15.06 |
Allison TC-10
| Gear | Ratio |
|---|---|
| 1 | 7.36 |
| 2 | 5.49 |
| 3 | 4.08 |
| 4 | 3.03 |
| 5 | 2.25 |
| 6 | 1.67 |
| 7 | 1.24 |
| 8 | 1.00 |
| 9 | 0.74 |
| 10 | 0.64 |
| Reverse | 8.85 |
Available Axle Ratios
The 2019 International LT offered a vast selection of Meritor and Dana Spicer axle ratios to precisely match the intended application, whether it be long-haul efficiency or heavy-haul capability. These ratios are not tied to a specific trim but are chosen based on the engine, transmission, and intended use.
| Ratio | Best For |
|---|---|
| 2.26 | Fuel Economy |
| 2.39 | Fuel Economy |
| 2.47 | Fuel Economy |
| 2.64 | Fuel Economy |
| 2.85 | Balanced |
| 3.08 | Balanced |
| 3.21 | Balanced |
| 3.36 | Balanced |
| 3.55 | Balanced |
| 3.70 | Towing |
| 3.91 | Towing |
| 4.10 | Towing |
| 4.30 | Towing |
| 4.56 | Heavy Towing |
| 5.29 | Heavy Towing |
How to Identify Your Axle Ratio
Unlike consumer trucks, heavy-duty trucks like the International LT don't typically have RPO codes on a door jamb sticker for the axle ratio. Identification is usually done in one of two ways:
- Axle Tag: Look for a metal tag bolted to the differential housing of the rear axle. This tag will have the ratio (e.g., "3.55") stamped directly on it.
- VIN Decoder/Line Setting Ticket: The most reliable method is to use the vehicle's VIN to get the original "line setting ticket" or build sheet from an International dealer or an online service. This document lists every component the truck was built with from the factory, including the exact axle model and ratio.
Towing vs. MPG Impact
Choosing the right axle ratio is a critical balancing act between fuel efficiency and pulling power.
- Numerically Lower Ratios (e.g., 2.26, 2.47): These are considered "fast" gears. The engine turns at a lower RPM at highway speeds, which significantly improves fuel economy. These ratios are ideal for long-haul carriers operating on flat terrain with lighter loads.
- Numerically Higher Ratios (e.g., 3.91, 4.30): These are "slow" or "tall" gears. They multiply the engine's torque more effectively, providing superior pulling power for getting heavy loads moving, especially on steep grades. The trade-off is higher engine RPM at speed, which leads to lower fuel economy.
Common Issues
While the Dana and Meritor axles used in the LT are known for their durability, they are not immune to issues, especially under heavy use.
- Ring and Pinion Whine: A howling or whining noise that changes pitch with vehicle speed can indicate a problem with the ring and pinion gear set. This could be due to improper backlash, worn gears, or contaminated lubricant.
- Carrier Bearing Failure: A rumbling or growling noise, particularly on acceleration or deceleration, can point to failing carrier bearings. If left unaddressed, this can lead to catastrophic failure of the differential.
- Limited-Slip Clutch Wear: In axles equipped with limited-slip differentials, the internal clutches can wear out over time, reducing their effectiveness. This is often noticed as a one-wheel-peel situation where one tire spins freely while the other has no power.
Find a driveline shop on Repairius.
More specs for the 2019 International LT
Oil Capacity & Filter
Capacity, weight, filter PN, drain plug torque, change interval.
Fluid Type Specs
Engine oil, coolant, ATF, diff, brake, PS, DEF — with OEM spec numbers.
Coolant Capacity & Type
Total system capacity, OEM coolant spec, flush interval, bleed tips.
Transmission Fluid & Service
Trans model, fluid spec, capacity, filter PN, service interval.
Torque Specifications
Lug nuts, drain plug, caliper, axle nut, plug, key fasteners.
Brake Pad & Rotor Specs
Pad PNs, rotor size, min thickness, caliper torque.
Tire Size & Pressure
OEM size, cold psi, bolt pattern, wheel size, TPMS.
Battery Size & Group
Group size, CCA, AGM/flooded, dimensions, reset note.
A/C Refrigerant & Oil
R-134a or R-1234yf, charge oz, PAG oil spec.
Bulb Sizes (Headlight, Tail, Fog)
Headlight, fog, tail, turn, reverse, interior.
Factory Maintenance Schedule
Service intervals by mileage, severe-duty notes, known issues.
Towing Capacity & Payload
Max tow, payload, GVWR/GCWR, hitch class by trim.
Fuse Box Diagram & Amperage
Fuse box locations, layout, amps, and what each fuse controls.
Serpentine Belt Routing & Length
Belt routing, length, rib count, OEM + aftermarket PNs.
Wheel Alignment Specifications
Camber, caster, toe ranges (front & rear), adjustability notes.
Paint Color Codes
All factory colors with paint codes, sticker location, touch-up tips.
Wiper Blade Sizes
Driver/passenger/rear blade size, attachment, OEM + cross-refs.
Spark Plug Type & Gap
Plug PN, gap, torque, interval by engine.
Key Fob Programming
DIY programming steps, FCC ID, fob PN, battery, transponder.
Same spec — other model years
Maintenance & repair guides
2019 International LT Maintenance Schedule →
Available maintenance guidance; confirm the manufacturer schedule.
Repair planning references →
Plan the scope of work; detailed procedures need configuration-matched evidence.
Browse by make
Running an auto or diesel repair shop?
Compare Repairius to the shop software you're paying for
$99.99/month (first location included), unlimited users, 14-day free trial.