Since automatic transmissions first appeared in volume production, their hydraulic circuits have relied on fine filtration to keep the transmission fluid clean and the valve body shifting reliably. The hydraulic filter for the automatic transmission sits inside the sump, capturing the fine metal particles and friction material debris that accumulate through normal clutch pack cycling. Unlike an oil filter on a petrol or diesel engine, the automatic transmission filter is often submerged in the fluid it cleans and may not have a conventional paper element — many designs use a mesh or felt media that cannot be cleaned and must be replaced with the fluid at each service. When a blocked or collapsed filter restricts fluid flow to the hydraulic circuit, the first symptom is typically sluggish or jerky gearshifts, particularly when the fluid is cold and viscosity is highest. In severe cases, shift hesitation progresses to slipping, then to complete refusal to engage a gear. Mahle and Vaico are well-regarded suppliers for these filters across Mercedes-Benz, Volkswagen, Audi, BMW, and Toyota applications. Because the filter housing dimensions, bypass valve calibration, and sump gasket interface are specific to each gearbox variant, matching the OE number is the only way to ensure proper installation and correct hydraulic resistance — a filter from a closely related but incorrect application may fit physically but alter valve body pressure in ways that damage shift quality.
Browse all Automatic transmission hydraulic filter in our catalogue
Hydraulic filters are gearbox-specific: housing shape, media grade, bypass valve calibration, and the sump pan gasket that typically comes with the filter kit all vary between transmission families and even between generations of the same gearbox model. Each listing on this page shows the TecDoc OE references mapped to specific transmission variants. Use your vehicle's make, model, engine, and build year. If your gearbox has been remanufactured or swapped, confirm the actual transmission code stamped on the housing before ordering.
OEM filters from suppliers such as Mahle are manufactured to the gearbox builder's exact media specification and bypass valve setting. Quality aftermarket equivalents from Vaico carry the same OE cross-references and are tested to the same hydraulic resistance tolerances. Budget filters may use incorrect media porosity — either too coarse (failing to catch debris) or too fine (restricting flow) — and may include a sump gasket that does not seal correctly, causing leaks and fluid loss that accelerate clutch wear.
Service intervals vary widely by manufacturer. Some gearboxes are specified as 'lifetime fill' with no scheduled change — though most specialists recommend fluid and filter service every 40,000–60,000 miles regardless, particularly if the vehicle is used for towing or in stop-start urban traffic that stresses the clutch packs harder than motorway driving. If the fluid has turned dark brown or smells burnt rather than having its normal red or amber colour, an overdue service is confirmed and the filter should be replaced alongside the fluid.
The clearest indicator is a shift quality change — gears that once changed smoothly now feel hesitant or jerky, particularly from cold when fluid viscosity amplifies any restriction in the circuit. Delayed engagement when selecting Drive or Reverse from Park, a brief 'flare' where engine revs rise without a corresponding increase in vehicle speed, and — in severe cases — the gearbox entering limp-home mode and locking into a single gear are all consistent with insufficient hydraulic pressure caused by filter blockage. Checking the fluid level and condition should always accompany any gearbox complaint.
Showing 100 of 1,345 Automatic transmission hydraulic filter OE numbers. Enter the OE on the main OE search to jump to any reference.
