Mitsubishi Pick-ups and Montero 1983-1995 Repair Guide

Automatic Transmission



Do not overfill the transmission. An electronic fluid level sensor, available on some vehicles, provides a convenient means of checking the transmission fluid level. allow the engine to idle and observe the transmission warning lamp for 30 seconds. If lamp remains OFF, it is not necessary to proceed further. If the lamp glows, the fluid level should be checked manually.

Check the automatic transmission fluid every 30,000 miles (48,000 km). The fluid level in these units is very sensitive to heat and must only be checked when the unit is at normal operating temperature. Drive the vehicle until a few miles after the engine has reached operating temperature. Then, with the engine idling, engage every gear selector position for a few seconds. Finally, put the gear selector in the Neutral position and securely engage the handbrake.

Remove the dipstick, wipe it, reinstall it all the way, and remove it again. Fluid level should be between the two marks on the stick. If the fluid level is at the lower mark, gradually add one pint to bring the level even with the upper mark on the dipstick. Do not overfill the transmission as this will cause foaming of the fluid and operating problems.

You should add Dexron®II automatic transmission fluid only. Turn the engine OFF and add the fluid with a small funnel through the transmission dipstick tube. Mitsubishi recommends against the use of any transmission additives whatsoever.


See Figures 1 and 2

Most trucks do not have a torque converter drain plug. No attempt should be made to drain the torque converter. If the vehicle is equipped with an oil pan drain plug, remove the drain plug (replace the gasket, if so equipped, upon installation) and drain the fluid. Reinstall the drain plug and tighten to 13-17 ft. lbs. (18-23 Nm). Refer to the service procedure for reference only.

It's best to change the fluid with the transmission hot. Drive the vehicle until the transmission is warmed up; a few miles after the engine temperature gauge reaches normal levels. Then follow these steps:

  1. Support the vehicle securely on jackstands or ramps. It should be reasonably level.
  3. There is no drain plug on most Mitsubishi automatic transmission oil pans. To remove the pan, loosen all the pan bolts a few turns, but do not completely remove and then place a large container under the oil pan. Tap one corner of the pan with a soft hammer to break the seal.
  5. Once the pan seal is broken loose, support it, remove all the bolts, and then tilt it to one side to drain the fluid.

Check the fluid in the drain pan, it should always be a bright red color. It if is discolored (brown or black), or smells burnt, serious transmission troubles, probably due to overheating, should be suspected. The transmission should be inspected by a qualified service technician to locate the cause of the burnt fluid.

  1. Remove the attaching bolts and remove the filter assembly. This is located on the underside of the transmission in the area covered by the transmission pan. Most filters are held in place by four bolts, however the actual number of bolts may be different. Strainers may be cleaned in a safe solvent and air dried. Foam filters must be replaced.
  3. Install the filter or strainer and tighten the bolts alternately (diagonally) in several stages.
  5. Clean all the gasket surfaces thoroughly. Then, put the pan and new gasket in position with bolt holes aligned. Reinstall the bolts, tightening them only very gently with your fingers.
  7. Tighten the bolts, using a diagonal pattern, in several stages to 12 ft. lbs. (17 Nm). Pour fluid in cautiously until it reaches the lower mark on the dipstick. Refer to the Capacities Chart for the amount you will need. Start the engine, put the gear selector in each of the positions for several seconds, and then go back to Neutral. Check the fluid level again and make sure it's above the lower mark. Drive the vehicle until the transmission is hot, then add fluid gradually until it has reached the full mark.

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Fig. Fig. 1: Automatic transmission dipstick-all models similar

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Fig. Fig. 2: Automatic transmission drain plug, if so equipped


Refer to Drive Train for complete service procedures.