The AX15 is a five-speed transmission built by Aisin-Warner for Jeep, beginning in 1987. The transmission is no longer in production, but Aisin-Warner continues to produce the rebuild kits and parts to repair it. The rebuild kit comes with all the parts of the transmission that must be replaced. The remaining parts can be cleaned and inserted back into the AX15 during reassembly. By today's standards, the transmission is a simple design, but you still need a lot of mechanical skill and transmission knowledge to rebuild this drivetrain.
Jack up one side of the Jeep, using the tire jack that came with the vehicle. The frame of the Jeep must be high enough to set a jack stand under that corner of the vehicle. Raise the front of the Jeep first, and then move to the back of the vehicle, until all four wheels are off the ground. The space between the transmission and ground must be enough to drop the transmission, once it is removed.
Drain the transmission fluid, after placing the drain pan underneath the drain hole. Use your ratchet and socket to remove the drain plug, and let all the transmission fluid drain into the pan. Wait until the transmission fluid quits dripping from the drain hole, before proceeding to the next step.
Rest the hydraulic jack and transmission cradle under the transmission. Raise the jack and cradle until it is snug against the bottom of the transmission. This ensures that the transmission will not fall when you unbolt the component.
Remove the driveshaft bolts by removing the coupling bolts. The Jeep is a four-wheel drive and has driveshafts running to the front and rear wheels. Once the shafts are removed, begin removing the five-speed lock nut and shift knob from the shift levers of the transfer case. Remove the clutch housing, any speedometer cables, vacuum hoses and other components that connect to the main frame of the transmission. The last bolts that must be removed are main transmission bolts that connect the component to the engine.
Lower the transmission after removing all the connecting bolts. The hyrdraulic jack has a release screw on the side of the tool. Slowly turn the release screw until the transmission begins to slowly drop from the Jeep. Slide the AX15 from underneath the Jeep, and place it in a location where you can gain access to the internal components of the transmission.
Remove all the internal components, one at a time. Lay the components out in a line, and keep them in the order of disassembly. This will help you remember what order each part goes back into the AX15.
Clean out the inside of the transmission body with a rag. Grime and grit tend to stick to the sides of the transmission casing. Scrape this dirt and debris off the inside of the casing, and wipe it down again to remove all the debris.
Reassemble the internal components in the reserve order of disassembly. Replace the old parts with the new parts that came in the AX15 rebuild kit. This will include some gears, bearings, gaskets and seals. Wipe down each old part that is inserted back into the transmission. Make sure you tighten each part in place, before inserting the next internal component.
Install the AX15 transmission is the reverse order of removal. Once you have secured the transmission back in place, fill the transmission with fluid. Check for any leaks before removing the jack stands and lowering the wheels back to the ground.
