The Borg-Warner T18 is a heavy-duty transmission designed for and used in 1/2, 3/4, and 1+ ton trucks. Produced by Borg-Warner between 1965 and 1991. The T18 is the improved successor to the T98 transmission.
This transmission has four forward gears and one reverse. Only second, third, and fourth are synchronized gears.
The T18 transmission was found in Ford, Jeep and International Harvester (IH) trucks. Because of this, there are many variations of this transmission found across all three makes of vehicles.
Ford
Jeep
The 1972-1975 Jeep CJ T18s had the narrow ratio gearing (1st gear 4.02) and bolted directly to the AMC bellhousing. These transmissions can be adapted to fit GM engines. Read more here.
In 1976, the T18 could be found in the Jeep CJs as well as Jeep Full-Sized Cherokee and Trucks. In the CJ, the gear ratio was the narrow ratio starting with 4.02:1 ratio. In the Full-Sized Jeeps, the T18 came with the wide ratio starting with 6.32:1 ratio. These and all Jeep CJs through 1979 had a stick-out measurement of 7.43″.
All Jeep CJs from 1977-1979 had the wide-ratio T18 with the 6.32:1 ratio first gear. The 1976-1979 T18As can also be adapted to GM engines using adapters. Read more about that here.
All Jeep T18s had no front adapter plate and were mounted directly to the AMC bellhousing.
International Harvester
The IH T18 was only available in 3 versions: T18, T18A, and T18C. The standard T18 featured the same gear ratios as the wide ratio Ford and Jeep T18s (with 1st gear starting in 6.32:1 ratio). The T18A had 4.02, 2.41, 1.41, 1.0 ratios. The T18C had 4.02, 2.41, 1.52, 1.0 ratios.
Due to the unique input shaft and stud-mounted front face, the variations of the IH T18 are not recommended for Jeep conversions.
Gear Ratios
| Reverse | 7.44 | 4.73 |
| 1st Gear | 6.32 | 4.02 |
| 2nd Gear | 3.09 | 2.41 |
| 3rd Gear | 1.69 | 1.41 |
| 4th Gear | 1.00 | 1.00 |
Fluid Type and Capacity
| Lubricant | SAE 90W GL4 SAE 80W-90 GL4 |
| Capacity | 3.25 qts (3L) Fill to hole |
Other Specifications
| Weight | 145lbs |
| Length | 11.87″ |
| Height | 17.5″ |
| Input Splines | 10 |
| Output Splines | 6 |
| Pilot Tip Diameter | ~17mm |
Transfer Case Compatibility
Engine/Bellhousing Compatibility
Ford –
Write-ups and Tutorials
To Be Completed
