Parts for your 2006 Toyota Mark x-Transmission filter

2006 Toyota Mark X transmission filter — what it is and when to service it

For the 2006 Toyota Mark X (GRX120/GRX121), a transmission filter is indeed used. The vehicle runs an Aisin 6‑speed automatic (commonly A960E/A761E), which uses an internal transmission oil strainer mounted to the valve body inside the sump pan. Toyota’s Electronic Parts Catalogue lists this as the “Oil Strainer Sub‑Assembly, AT” (e.g., 35330‑30080/35330‑30050, varying by spec), and the Toyota/Aisin service procedures show pan removal and strainer replacement as a valid repair step. Fluid spec is Toyota ATF WS.

What does that filter do? It screens clutch material, fine metal, and seal debris before oil reaches the pump and valve body, helping the Mark X shift cleanly and protecting the solenoids. Unlike an engine oil filter, this is not a quick external spin‑on, it’s a bolted-in strainer inside the transmission, so it’s not set up for frequent changes. Toyota’s servicing guidance for WS “sealed” units focuses on fluid condition first, with filter replacement typically done when the pan is off, during higher‑mileage servicing, if shifting issues arise, or whenever contamination is found.

For owners who want to look after the box, a sensible approach in Australia and New Zealand is:

• Use only Toyota ATF WS. A standard drain‑and‑fill replaces about 3.5–4.5 litres, full fill is roughly 7.5–8.5 litres depending on variant.
• Consider a pan drop and new strainer if there’s clutch dust in the pan, the magnet’s heavily loaded, shifts feel rough, or after a fluid overheat event (e.g., heavy towing).
• If doing a pan service: renew the pan gasket (or use Toyota FIPG where specified), clean the magnets, and torque pan bolts correctly (low torque, typically under 10 N·m).
• Set fluid level at the correct temperature using the overflow plug method (ATF ~40 °C). A scan tool that reads ATF temp helps avoid over/underfill.

How often? There’s no fixed Toyota interval for the strainer, but many workshops will inspect/replace it around 150,000–200,000 km or sooner if symptoms show. Routine fluid refreshes every 60,000–100,000 km (more often for towing or hot city work) keep the hydraulics happy. If in doubt, confirm the exact transmission code and parts by VIN, as filter and gasket part numbers vary across Aisin families.

• Does a 2006 Mark X have a serviceable transmission filter?

Yes. It uses an internal oil strainer inside the pan, not an external canister. It’s typically replaced when the pan is removed for inspection or repair, rather than on every fluid change.

• How often should the transmission filter be replaced on a Mark X?

There’s no strict interval. Many techs inspect it around 150,000–200,000 km or earlier if there are symptoms like harsh shifts or dirty fluid. Prioritise ATF condition, replace the strainer when contamination is present or the pan is already off.

• What fluid should be used and how much goes in?

Use Toyota ATF WS only. A drain‑and‑fill is typically 3.5–4.5 litres, total capacity is roughly 7.5–8.5 litres depending on transmission. Set the level at the correct temperature using the overflow plug method.