Parts for your 1990 Mitsubishi Pajero-Transmission fluid

1990 Mitsubishi Pajero transmission fluid: what it is, when to change it, and what to use

For a 1990 Mitsubishi Pajero, “transmission fluid” is relevant if it’s fitted with the 4‑speed automatic. Those autos use ATF (Automatic Transmission Fluid). Manual Pajeros from the same year don’t use ATF, they run a dedicated manual gearbox oil instead. This split is documented across Mitsubishi’s L040-series workshop manuals and owner’s manuals for 1989–1991, common repair guides like the Haynes Pajero/Montero 1983–1997 manual, and Aisin-Warner documentation for the period 4‑speed unit (AW/03‑72 family) specifying Dexron‑II type ATF.

On automatic models, transmission fluid does a lot of heavy lifting. It lubricates gears and bearings, provides hydraulic pressure for shifts, cools the unit under load, and protects internal parts from wear and varnish. When the fluid’s old, overheated, or the wrong spec, shifts get lazy, flare or thump, and the box can run hotter than it should—none of which the Pajero loves, especially if it’s towing or slogging through sand and bush tracks.

For fluid spec, period literature points to Dexron‑II ATF for the 1990 Pajero auto, quality modern Dexron‑III fluids are commonly used as a service replacement where Dexron‑II is specified. Always confirm against the vehicle’s build plate and the service manual before filling. Check ATF level hot, on level ground, in Neutral, and aim for clean, bright red fluid with no burnt smell.

As a rule of thumb for Aussie and Kiwi conditions, changing the ATF every 40,000–60,000 km (or 2–4 years) keeps the shifts tidy. If the Pajero tows, works hard off‑road, or sees lots of heat, shorten the interval. Many 1990 units have a serviceable pan and strainer—dropping the pan to replace the gasket and clean or replace the filter/strainer is worthwhile. A full exchange can refresh more of the old fluid, but a careful pan service plus multiple drain-and-fills can get you very close without special equipment.

• Use the correct ATF (Dexron‑II/III where specified) and don’t mix incompatible types.
• Inspect cooler lines and the radiator’s trans cooler for leaks or kinks.
• If the fluid is brown/black or smells burnt, service it sooner rather than later.
• Remember: manual 1990 Pajeros use manual gearbox oil, not ATF.

Technical references: Mitsubishi Pajero/Montero 1983–1996 Workshop Manual (L040 Series, Power Train), 1989–1991 Mitsubishi Pajero Owner’s Manual, Haynes Repair Manual Mitsubishi Pajero/Montero 1983–1997, Aisin‑Warner AW/03‑72 automatic transmission service data calling for Dexron‑II ATF.

Popular questions

What transmission fluid type does a 1990 Pajero automatic use?
Period Mitsubishi and Aisin-Warner specs call for Dexron‑II ATF. These days, a quality Dexron‑III fluid is commonly used as a service replacement where Dexron‑II was originally specified. Always verify against your specific transmission tag and workshop manual.

How often should the ATF be changed on a 1990 Pajero?
For typical Australian and New Zealand use, every 40,000–60,000 km or 2–4 years is a sensible interval. If it tows, goes off‑road a lot, or runs hot, shorten the interval and keep an eye on colour and smell.

Does a manual 1990 Pajero use transmission fluid?
Not ATF. Manual gearboxes take a dedicated manual transmission oil (typically a 75W‑90 meeting the correct GL rating per the workshop manual). Using ATF in a manual box from this era would be incorrect.