Parts for your 1986 Mitsubishi Pajero-Transmission filter

1986 Mitsubishi Pajero transmission filter: what’s fitted and how to look after it

Based on first‑gen Pajero factory service literature and Australian workshop manuals (Gregory’s/Max Ellery), plus the Aisin‑Warner 03‑72 series overhaul manuals used for the period Mitsubishi automatics, the 1986 Mitsubishi Pajero runs two very different setups: manual gearboxes have no transmission filter, while the 3‑ or 4‑speed automatic uses an internal, pan‑mounted strainer (often called a transmission filter). That strainer sits above the sump and protects the valve body and pump from clutch material and fine wear particles.

Why no filter on the manuals? The 5‑speed manual boxes circulate oil by splash rather than a pump, run heavier gear oil, and rely on a magnetic drain plug to catch wear debris. There’s simply no high‑flow fluid circuit to filter, so a replaceable filter isn’t used, correct oil and regular changes do the job.

For automatic 1986 Pajeros, the transmission filter’s purpose is straightforward: keep the ATF clean enough that the pump, valves and clutches can work crisply without starving for fluid or ingesting grit. The mesh strainer traps larger particles while magnets in the pan collect the superfine stuff. When the strainer is restricted, shifts get lazy, the pump can whine, and the box may flare between gears.

Good service practice is to drop the pan, clean the magnets, and replace or clean the strainer at sensible intervals. For typical Aussie and Kiwi conditions, doing this every 60,000–100,000 km (or sooner if towing, sand work, or lots of stop‑start) keeps the hydraulics happy. Always fit a new pan gasket, torque the pan bolts evenly, and make sure the strainer’s O‑ring seals properly to prevent aeration. Refill with the spec’d ATF for the Aisin‑Warner unit used in the Pajero of that era (originally a Dexron II type, modern Dexron III/Mercon equivalents are commonly used—check the manual or trusted transmission data). After refilling, warm the trans, cycle through the gears, and set the level with the vehicle idling in Neutral on level ground. Don’t overfill, foamed ATF is just as bad as low fluid.

Handy signs the auto filter/strainer may need attention:

• Delayed engagement into Drive or Reverse
• Soft or flared upshifts, especially when hot
• Pump whine or a faint buzzing at idle in gear
• ATF darkening quickly after fresh fluid

For manual 1986 Pajeros, skip the filter talk: service means draining the gear oil at the correct interval, inspecting the magnetic plug for fuzz (a little is normal), and refilling with the right GL‑rated oil to the proper level.

Popular questions

Does a 1986 Pajero manual have a transmission filter?

No. The manual box uses splash lubrication with gear oil and a magnetic drain plug to capture wear particles. There’s no pump‑driven circuit to filter, so a replaceable transmission filter isn’t part of the design.

How often should the automatic’s transmission filter be serviced on a 1986 Pajero?

As a rule of thumb, drop the pan and clean/replace the strainer every 60,000–100,000 km, sooner if the vehicle tows, sees beach work, or lives in heavy traffic. Always pair it with fresh ATF and a clean pan/magnets.

Can they just flush the ATF instead of dropping the pan?

A fluid exchange alone won’t clean the pan magnets or the strainer. The better approach is pan‑off service so the strainer can be inspected and the debris physically removed, then, if desired, follow up with a gentle exchange.