AW4
Possibly the most iconic automatic transmission put into Jeeps was the Aisin-Warner AW4. This was a 4-speed transmission used in the Cherokee XJ and MJ between 1987 and 2001. It is also found in the Grand Cherokee, but only during the 1993 model year. This transmission is most typically found paired with the AMC 4.0L Inline-6 engine and can come in both 2WD and 4WD versions.
AW4 Gear Ratios
| 1st Gear | 2.80 |
| 2nd Gear | 1.53 |
| 3rd Gear | 1.00 |
| 4th Gear (Overdrive) | 0.75 |
The transmission is known for being moderately reliable, as long as it’s maintenance is kept up and it doesn’t overheat. For those who live in hot climates, adding an auxiliary transmission cooler is recommended.
Early models of the AW4 had a 21 spline output shaft for connecting to the transfer case (1990 and earlier), but in 1991 the AW4 was outfitted with a 23 spline output shaft. Keep this in mind when determining which transfer cases will work with your transmission.
Read more about the AW4 transmission here.
