The AX-5 first came to the market in the 1984 model of Cherokee Jeep XJ. In fact, all the stock TJ, XJ, and YJ models introduced that year all the way to 2006 were equipped with this standard shift five-speed manual transmission. It also came with the AMC 150 4-cylinder engine in Wrangler models from 1987 to 2002. The AX-5 was designed mainly for light-duty vehicles with 4-cylinder and 6-cylinder engines. Some variants of the same transmission model can be found in some light truck applications and cars by Toyota as well.
Despite its prevalence, the AX-5 is generally considered dissatisfying especially in terms of strength. As a result, Jeep’s decision to put the transmission into off-road vehicles remains somewhat questionable. Even in all-stock vehicle versions, failures are not uncommon. This is probably one of the main reasons that Jeep owners seem to always try convert this particular transmission model with some stronger alternatives (i.e. the AX-15). Some auto repairs do not even offer conversion to V8 or V6 power due to the high probability of unsuccessful attempts, although it was in fact introduced in a Jeep model that utilized GM 2.8L V6 engine. The good news is that you can still find AX-5 Manual Transmission for Sale from reputable sellers or even online. Aisin, the manufacturer of the AX-5, also made smaller version called the AX-4. Both are essentially the same except for the lack of the overdriven fifth-gear in the latter.
Some predominant features of the AX-5 include its split-case made of aluminum, rear-positioned shifter, and cast-iron middle-adapter plate that separates the entire transmission’s front and rear sections. The AX-5 has four bolts to retain the shifter and 21 spline-output shaft designed to mate to NP231 and NP207 transfer cases. The transmission if fully-synchronized in all gears; also, all gears are helically cut.
|AX-5 Gear Ratios|
In case you are in the market to replace an AX-5 with an alternative, it is possible that you are led to believe that AX-15 would fit the bill, as they are indeed deceivingly similar to each other. Spline counts as well as the bell housing pattern appear to be exactly the same, but unfortunately both are not interchangeable, at least without some serious modifications.
Bear in mind that AX-5 is directly related to several models of commonly used transmissions for examples Wrangler 6-cylinder AX-15 and Toyota Truck R151, G52, and W58. They were also all manufactured by Aisin. A more thorough inspection of the input (NOT output) spline count should identify the difference.
Before you rush to the market and look for a rebuilt AX-5 Transmission for Sale, be aware of the fact this component was originally intended to be fitted with smaller horsepower engine. The overall longevity of the transmission is heavily affected by tire size, driving style, overall vehicle weight and of course maintenance.
While the longevity has been found questionable (even with stock 4 cylinder engines), you can improve your chances of having a durable long-lasting transmission for decades as long as you practice proper maintenance and of course informed judgment before committing to a conversion.