The Borg-Warner T86 transmission was a three-speed transmission installed in the Jeep CJ in 1966. It was mounted behind the Buick “Dauntless” V6 engine. It was replaced by the T14 transmission by mid 1967.
Only the second and third gears are synchromesh.
The T86 transmission has a 1.125″ x 10 spline input shaft. Length of the input shaft varies with application. The output shaft was 1.375″ x 6 spline. The original mounting to the Buick engine used a 2.5″ thick cast iron adapter plate. The adapter plate can also be used with a Chevy V8 bellhousing without any modifications.
The transmission was used behind the Dauntless V6 engine in the CJ-5, CJ-6, CJ-5A, and CJ-6A. The model number is AS7 T86AA. For the DJ-5 and DJ-6, the transmission the AS9 T86AA.
The factory service manual called for changing the transmission fluid every 12,000 miles with SAE 90W or 80W GL4 fluid. It is OK to use 80W-90 fluid, just be sure to not use any fluid labeled “Severe” and ensure the fluid is safe for brass synchros. Avoid GL5 gear oil.
Due to it’s low usage and weakness, this transmission is often not used for swapping.
Gear Ratios
| Reverse | 3.79 |
| 1st Gear | 2.79 |
| 2nd Gear | 1.68 |
| 3rd Gear | 1.00 |
Fluid Type and Capacity
| Lubricant | SAE 90W GL4 SAE 80W GL4 |
| Capacity | 1.25 qts (1.18L) |
Other Specifications
| Weight | 75lbs |
| Length | 9″ |
| Height | 14″ |
| Input Splines | 10 |
| Output Splines | 6 |
| Pilot Tip Diameter | unknown |
Transfer Case Compatibility
The T86 came factory with the Jeep Dana Spicer Model 18 transfer case attached (large bore versions only)
Engine/Bellhousing Compatibility
GM – The T86 was factory mounted to the Buick “Dauntless” V6. The adapter plate for this transmission can also be mounted to the Chevy V8 bellhousing.
AMC – This transmission was never used on AMC engines.
Write-ups and Tutorials
To Be Completed
