Nissan 31020-45X64 Automatic Transmission

Cut off the battery power, take out the throttle cables, drop the gear lever assembly, unplug the safety switch and shift controller power wires. First, lift up the car and safeguard its position. Unplug the drain plug connected to the torque converter, but if there's no converter drain plug available, you can drain the transmission instead (using your other hand). If there is also no transmission drain plug, take out the pan to prevent dirt from entering and then replace the drained pan. Remove three parts: the front exhaust pipe, vacuum tube, and speedometer cable. Then close the fluid cooler tubes with plugs to stop fluid from leaking. Lift the engine and transmission while removing the driveshaft and starter. Place support jack under the engine oil pan to lift the transmission and give needed support. Slide out the rear crossmember, pay attention to the way the torque converter and drive plate fit together, and detach the bolts joining the torque converter to the drive plate, turning the engine as needed. Loosen and take out the transmission bolts from the engine. Label each bolt, for precise reinstallation later - a must-learn during 240SX service. Measure runout on the drive plate with a dial indicator. Keep the results below 0.020". After installing the torque converter, measure the space from its face to the edge of the housing to confirm it exceeds 1.02 inches (26mm). Nut up the drive plate, fix the drive plate to converter with safe torque setting, and bolt engine to transmission while also securing the converter housing to engine properly, tightening the drive plate-to-torque converter bolts to 29-36 ft. lbs. (39-49 Nm) with specific torque for each bolt. Turn the crankshaft carefully a few times to make sure the transmission can move without any problems. Add the rear cross member, then remove engine and transmission supports to put in place the starter, and join the driveshaft while fastening its bolts with 29-33 pound-force feet n.m. Unplug, attach, then tighten all heater and water cooling tubes; reconnect the speedometer cable and the vacuum pipe; install a new exhaust pipe section at the front; join transmission controls to their wiring; connect the shift lever unit; reconnect the battery cable; refill the transmission to its proper volume; plan any shifts to fix issues. Do a road test, then look at the amount of fluid in the transmission.

For automatic transmissions, the serial number is located on the lower right side of the case.

Always dip bolt threads into clean transaxle oil before installing them into aluminum parts, and use antiseize compound to prevent galling.

Coat the lip of the new front cover oil seal with clean transmission fluid and press the seal into the front cover using the proper tool.

Always dip bolt threads into clean transaxle oil before installation and use a torque wrench to prevent thread stripping.

Tag the transmission-to-engine bolts for proper tightening during installation.