Mitsubishi Pick-ups and Montero 1983-1995 Repair Guide

Manual Transmission



The manual transmission filler plug is located on the side of the unit. Be careful to identify the drain plug on the bottom and differentiate it from the filler plug on the side.

With the vehicle parked on a level surface and the wheels blocked, remove the filler plug. It may be necessary to raise and support the vehicle on jackstands if the plug is inaccesible when the vehicle is on the ground. If the fluid runs out of the hole, the level is okay and you can immediately reinstall the plug. If fluid does not run out, you can stick your finger into the hole to check the level. As long as its level is at or near the bottom of the hole (no more than about 1 / 4 inch (6mm) below) the level is ok. If necessary, add API GL-4 fluid with a viscosity of SAE 80W or SAE 75W-85W. You may want to purchase a syringe-like device for adding small quantities of such fluid from your local automotive parts store.


See Figure 1

Whenever you plan to change the transmission fluid, purchase a new drain plug gasket ahead of time. This item should be replaced at each fluid change to ensure a good drain plug seal.

  1. Warm the engine until it has reached normal operating temperature.
  3. Park the vehicle on a level surface, place the transmission in Neutral, apply the parking brake and block the rear wheels.
  5. It may be necessary to raise and support the vehicle on jackstands to access the drain plug on the transmission.
  7. Position a suitable drain pan under the transmission and remove the fill plug.

Click image to see an enlarged view

Fig. Fig. 1: Manual transmission drain and filler plug locations-all models similar

  1. Remove the drain plug and allow the oil to drain completely.
  3. Wipe off the threads of the drain plug and install the plug with a new gasket.
  5. Through the filler plug opening, add the proper amount of fluid (see the Capacities Chart) until the level is just below the bottom of the opening. If a small amount runs out, that's OK.
  7. Lower the vehicle if it was necessary to raise it in order to drain the transmission.
  9. After wiping the threads, install and tighten the filler plug.
  11. Drive the vehicle to allow the oil to reach operating temperature and then check the drain and fill plugs for leaks.