Parts for your 1990 Mitsubishi Pajero-Transmission filter

1990 Mitsubishi Pajero transmission filter — what’s fitted and how to look after it

Based on factory documentation and transmission manuals, the 1990 Mitsubishi Pajero with an automatic gearbox uses an internal, serviceable ATF strainer (often called a transmission filter) mounted inside the sump pan. Manual Pajero gearboxes of the same year do not use a transmission filter. Technical sources referenced: Mitsubishi Pajero/Montero Factory Service Manual (1989–1991) — Automatic Transmission section (V4AW2/Aisin-Warner family), Aisin-Warner 03-72/04-72 service literature, Mitsubishi ASA parts catalogue entries for 1990 Pajero AT strainer and pan gasket, and Haynes/Pitman manuals covering Pajero/Montero up to the mid-1990s.

For auto-equipped examples, the transmission filter’s job is to catch clutch material, fine metal and other debris before it can circulate through the valve body and hydraulic circuits. Keeping that strainer clean and flowing well helps maintain stable line pressure, crisp shifts and proper torque-converter operation, which is especially important for a Pajero that tows, tackles sand, or creeps along bush tracks in low range.

Servicing is straightforward and well worth doing. The pan is removed, magnets are cleaned, the strainer is replaced (or thoroughly cleaned if the design specifies reuse), and a new pan gasket is fitted. The unit is then refilled with the correct ATF for the era—check the factory spec for the exact variant fitted to the vehicle, many 1990 Pajero autos were specified for Dexron-II type fluid, and later guidance commonly accepts Dexron-III as suitable. Avoid “power flushing” older autos, a pan service with a sensible drain-and-fill is gentler and effective. After refilling, the fluid level should be set hot, in neutral, following the manual’s procedure.

How often? A practical interval in Australian and New Zealand conditions is about every 40,000–60,000 km or 2–4 years, with shorter intervals (around 30,000–40,000 km) if the vehicle tows, sees lots of stop–start city use, heavy off-road work, or water crossings. Owners should also keep an eye on the external cooler lines and radiator ATF cooler, as good cooling helps the fluid and clutches live longer.

Signs it’s due include delayed engagement into Drive or Reverse, flare between gears, harsher shifts, or ATF that’s gone dark or smells burnt. Catch those early, and a fresh strainer, clean pan and new fluid can restore smooth shifting and extend the life of a hard-working Pajero auto.

• Applies to: 1990 Pajero with automatic transmission (internal strainer in pan)
• Not applicable: Manual transmission models (no ATF filter fitted)

FAQs

Does a 1990 Mitsubishi Pajero have a transmission filter?
Yes, if it’s an automatic. It uses an internal strainer inside the trans pan. Manual gearbox models don’t have or need a transmission filter.

How often should the transmission filter and ATF be changed?
In local conditions, every 40,000–60,000 km (or 2–4 years) is sensible. If the vehicle tows, works hard off-road, or does lots of short trips, shorten it to about 30,000–40,000 km.

Which ATF should be used in a 1990 Pajero auto?
Follow the factory manual for the exact transmission. Many from this era specify Dexron-II, with Dexron-III commonly accepted. Don’t substitute modern SP-III unless the specific gearbox and service information say it’s compatible.