VAG 09G325429E OIL FILTER

The VAG 09G325429E is the Automatic Transmission Oil Filter / Strainer for the 6-speed Aisin AQ160 automatic transmission fitted to specific Volkswagen Group passenger vehicles (Golf Mk7 / Alltrack / SportWagen, Tiguan, Audi A3 / S3 1.8L variants, 2015-2018 production). The filter is an internal transmission component — a metal-pan-housed strainer assembly with rigid frame and synthetic / felt filter medium — that filters automatic transmission fluid (ATF) before it enters the valve body, torque converter circuits, clutch packs, and lubrication galleries. This is NOT an engine oil filter — despite the ok.parts listing description "Oil Filter", the part is an automatic gearbox internal filter, replaced only during transmission service operations (not at routine engine oil changes).

The transmission oil filter performs a critical filtration function within the automatic gearbox's internal hydraulic circuit. ATF (automatic transmission fluid) is the operating medium for multiple functions inside the 6-speed AQ160 transmission: (1) hydraulic actuation of clutch packs and brake bands via the valve body's electro-hydraulic solenoids; (2) lubrication of planetary gear sets, bearings, and clutch pack friction surfaces; (3) cooling of friction components through circulation through the transmission oil cooler; (4) torque transmission through the torque converter fluid coupling. Any debris in the ATF — friction-material wear particles from clutch packs, metallic wear from bearings and thrust washers, or carbon deposits from localised overheating — can clog the valve body's narrow control orifices, damage solenoid valves, and accelerate clutch pack wear.

The filter sits inside the transmission housing above the oil pan, drawing ATF up into the hydraulic circuit via the oil pump pickup. Captured debris accumulates progressively restricting flow. On high-mileage transmissions with extended service intervals, the filter becomes significantly loaded, restricting ATF flow and compromising clutch pack engagement timing and lubrication adequacy.

The 09G325429E filter is a genuine VW Group supplied component originally manufactured for VAG by a partnership with Aisin (the AQ160 transmission's Japanese manufacturer). The aftermarket equivalent supplied by ok.parts replicates the OEM filter media specification, frame geometry, and mounting hole pattern for correct fitment in the AQ160 transmission housing. The filter is an essential component of any AQ160 transmission service operation — replacement is mandatory whenever the transmission oil pan is dropped for ATF service, even if the existing filter appears visually serviceable.

Oil or fuel filters for internal combustion engines and transmissions are classified under HS 8421.23 (oil or petrol-filters for internal combustion engines). Confirm exact 10-digit subheading and applicable duty rates with your customs broker. Commercial invoice description: automatic transmission oil filter / strainer for 6-speed Aisin AQ160 transmission, synthetic / felt filter medium in metal frame, internal transmission service component.

Does NOT fit: VW / Audi vehicles with DSG (DQ250, DQ200, DQ500, DL501) dual-clutch transmissions — completely different transmission architecture, different filter references (DSG uses mechatronic-integrated filters); VW / Audi with 6-speed Tiptronic ZF 09L / 09M / 09P transmissions (Touareg, Q7, larger V6 / V8 applications) — ZF-designed transmissions with different filter references; VW / Audi with 8-speed ZF 8HP automatic transmissions (Audi A6 / A7 / A8 / Q5 / Q7 newer generations) — different transmission architecture; Manual transmission VW / Audi vehicles — no automatic transmission, no transmission oil filter applicable; 2.0L TDI diesel variants with AQ160 — verify by VW parts catalogue; some diesel AQ160 applications may use different filter reference; VW / Audi AWD / Quattro variants with AQ160 — verify; the verified application list above is for FWD "W/o AWD" configuration. Engine oil filter applications for these same vehicles use entirely different VAG references (typically 06H115561, 03L115562, or similar — consult specific service manual). Always verify by reading the OEM number stamped on existing filter before ordering, AND confirm with supplier via inquiry form that the part matches your specific VW / Audi VIN.

Difficulty: Moderate to Difficult. Estimated time: 90–180 minutes. Transmission service procedure is NOT a simple oil change — ATF fill specifically requires the VAG VCDS / VAS adaptation procedure to set correct fluid level at specified transmission temperature. Workshop equipment + VCDS tool access strongly recommended.

1. 1
   Park vehicle on level surface, allow transmission to cool fully (operating temperature ~80-100°C at service is dangerous to handle). Lift vehicle on hoist or using axle stands rated for vehicle weight; ensure safe and stable underbody access.
2. 2
   Position ATF catch container under transmission pan (capacity at least 6-8 L). The AQ160 transmission holds approximately 5.5-7 L of ATF, but full extraction requires drainage of fluid retained in torque converter and transmission cooler lines (depending on service procedure).
3. 3
   Remove ATF drain plug (if AQ160 application has one) and drain primary fluid volume. Some AQ160 applications require dropping the transmission pan for drainage; consult VW / Audi service manual for your specific vehicle.
4. 4
   Remove transmission pan bolts (typically 14-16 bolts around pan perimeter) and carefully lower the pan. Critical: pan contains residual ATF; lower carefully to avoid spillage. Inspect pan magnet and pan floor for metallic debris (small amount of fine "fuzz" normal; large flakes / fragments indicate internal wear).
5. 5
   Remove the old filter from inside the transmission. Filter is typically retained by 2-4 small bolts to the valve body or transmission housing. Photograph orientation and mounting bolt pattern before removal.
6. 6
   Compare new filter (09G325429E) to old — verify dimensions, mounting hole pattern, sealing surfaces match exactly. Confirm OEM number reads 09G325429E or supersession 9G325429E.
7. 7
   Install the new filter with new sealing O-ring or gasket (typically supplied with the filter, or separately as part of a transmission service kit). Torque mounting bolts to OEM specification (typically 6-10 Nm for small bolts — consult VW service manual for exact value).
8. 8
   Clean transmission pan thoroughly — remove all old gasket residue, debris, and magnetic accumulation from pan magnets. Wipe with clean lint-free cloth. Replace pan gasket with new gasket — reusing old gasket produces leak.
9. 9
   Refit transmission pan with new gasket, torque pan bolts in criss-cross sequence to OEM specification (typically 8-12 Nm for AQ160 pan bolts). Refit drain plug with new sealing washer.
10. 10
    Refill with fresh VAG-specified ATF — AQ160 uses G 055 005 or G 060 162 ATF specification (newer revision). Initial fill typically 4-5 L; final level setting requires VCDS adaptation procedure.
11. 11
    Critical: VCDS / VAS ATF level adaptation — connect VAG-COM / VCDS / VAS diagnostic tool, navigate to transmission control unit, run "ATF level check / set" adaptation. Procedure requires: start engine, hold brake, shift through all gear positions, return to Park, monitor transmission fluid temperature on diagnostic display; when fluid temperature reaches specified range (typically 35-45°C), open ATF level check plug and top up or drain to correct level. Close level check plug at correct level.
12. 12
    Test drive vehicle verifying smooth shifts at all gear ratios, smooth TCC lockup, no warning lights, no fault codes after drive cycle. Re-scan for transmission DTCs; clear any historical codes. For commercial fleet operations: schedule re-inspection after 1,000-2,000 km verifying no leak from pan gasket and normal transmission operation.