Classification: Reference: Date: AT87-008 TS87-172 November 23, 1987 CLEANING AUTOMATIC TRANSMISSION COMPONENTS APPLIED VEHICLE(S): All Nissan models equipped with automatic transmission or transaxle SERVICE INFORMATION Under severe service, some automatic transmissions or transaxles may become contaminated with burned fluid, clutch and brake material, or metal particles, all of which can cause reduced efficiency or damage. If the damage is not so extensive as to warrant transmission overhaul, use the following procedures to clean the contaminants out of the hydraulic system components before replacing the fluid. 1/5
SERVICE PROCEDURE CONDITION Burned oil. Clutch and brake material in oil. Metal particles in oil. *See attached pages. A/T COMPONENTS INCLUDING CONTROL VALVE BODY 1. In-vehicle fluid change/flush* OR 2. Disassemble component parts, flush with clean solvent. Air dry. (Do not use compressed air). Disassemble component parts, flush with clean solvent. Air dry. (Do not use compressed air). 1. Disassemble component parts, flush with clean solvent. Air dry. (Do not use compressed air). 2. If a lot of metal particles are found, replace control valve body. TORQUE CONVERTER 1. In-vehicle fluid change/flush OR 2. Solvent clean using torque converter cleaning machine. (May be done by an AT rebuilder.) Solvent clean using torque converter cleaning machine. (May be done by an AT rebuilder.) Replace torque converter. OIL COOLER AND PIPING In-vehicle fluid change/flush Heat exchanger cleaning procedure 2/5
In-Vehicle Fluid Change/Flush If the transmission or transaxle is contaminated with burned oil or clutch and band material, all fluid, including the fluid in the torque converter, must be changed and the transmission flushed out. Drain and replace the old fluid and use the following procedure to flush the assembly. 1. Disconnect the transmission oil cooling lines at the radiator heat exchanger. 3/5
2. Block the transmission oil return line. Connect a rubber line to the disconnected transmission oil out line and place the rubber line into a suitable oil drain pan. 3. Start the engine and allow the vehicle to run at idle in PARK. Oil will now be discharged out of the transmission oil cooler line. 4. Place a filler funnel into the transmission filler tube and slowly fill the transmission with new automatic transmission fluid. Replace the fluid at approximately the same rate that it is discharged out of the oil cooler line. This will be about 3 or 4 quarts per minute. CAUTION: DO NOT ALLOW THE TRANSMISSION TO RUN OUT OF FLUID. DAMAGE TO INTERNAL COMPONENTS COULD RESULT. 5. Run the engine and allow the flushing process to continue until the fluid discharged out of the oil cooler line is clear. This will require a total of about 7 quarts of fluid flushed through the system. 4/5
6. Stop the engine and perform the Oil Cooler/Heat Exchanger Cleaning Procedure described below. 7. After the flushing is completed, re-connect the oil cooler lines. Restart the engine and check for transmission fluid level. Refill as necessary. Oil Cooler/Heat Exchanger Cleaning Procedure If contaminants are found in the automatic transmission, there will also be contaminants in the oil cooler. Therefore, the cooler must be flushed or the materials that are present will find their way into the clean transmission. To flush the heat exchanger, use clean solvent in the following procedure. 1. Connect two long hoses (approximately 4 ) onto the radiator heat exchanger fittings. 2. Place one end of the hose onto the solvent discharge line of your shop solvent tank. 3. Run the second line back into the solvent tank. 4. Start the pump on the solvent tank and allow the solvent to flow for a minimum of ten minutes. 5. Disconnect the hoses at the radiator heat exchanger. Blow the heat exchanger out with compressed air at low pressure (10 psi maximum). Then reinstall the automatic transmission cooler lines. 5/5