Transmission Fluid Change

This procedure drains and refills the transmission fluid on the 2009 Aston Martin DB9 equipped with the Touchtronic 6-speed ZF automatic transmission, including filter replacement if accessible.

Warnings

Tools required

Parts

• Transmission drain plug crush washer × 1 — Use OEM specification for ZF 6HP26
• Transmission filter (if serviceable) × 1 — ZF 6HP26 internal filter or use OEM Aston Martin specification
• Transmission pan gasket (if removable pan) × 1 — Use OEM specification for ZF 6HP26

Fluids

• Touchtronic 6-speed ZF ATF — 9.5 qt

Preparation

1. Park vehicle on level ground and engage parking brake.
2. Allow engine and transmission to cool for at least 2 hours if recently driven.
3. Raise vehicle on lift or jack stands to provide access to transmission underside. Ensure vehicle is stable and secure.
4. Locate transmission oil pan and drain plug on underside of transmission. Clean surrounding area to prevent contamination during service.
5. Prepare drain pan and position under transmission drain plug area.
6. Have all replacement parts and fluid ready before beginning drain procedure.

Procedure

1. 1

   Access and remove undertray
   Remove the rear/transaxle undertray sections to access the transmission (rear transaxle) pan. These are typically secured with Torx fasteners around the perimeter. Remove the undertray fasteners and carefully lower the undertray, noting any clips or secondary fasteners at the rear edge. Set aside for reinstallation.
2. 2

   Drain transmission fluid
   Position the drain pan directly under the transmission drain plug. Using the appropriate drive tool for the drain plug (verify the exact drive type and size against OEM/ZF documentation before applying force), carefully loosen the drain plug. Verify the correct plug drive size before applying force. Once loose, remove by hand while maintaining pressure to prevent sudden fluid release. Allow fluid to drain completely into the pan, which may take 10-15 minutes. Inspect the drained fluid for metal particles, burning odor, or excessive discoloration indicating internal wear.
   ⚠Fluid may still be warm. Control the plug removal to prevent splashing.
3. 3

   Inspect drain plug and replace crush washer
   Once fluid drainage slows to drips, remove and inspect the drain plug threads and sealing surface for damage. Clean the plug threads and sealing surface with a clean shop towel, taking care not to damage the soft alloy sealing face. Remove and discard the old crush washer from the drain plug. Install the new crush washer onto the drain plug. Do not reuse the old washer as it will not seal properly.
4. 4

   Assess transmission filter accessibility
   Determine if the transmission pan is removable for filter service. On the ZF 6HP26, the pan is typically sealed and may require pan removal for filter access. If undertray removal reveals a removable pan with approximately 17-20 perimeter bolts, proceed to filter replacement. If the pan is not designed for routine removal or no bolts are visible, skip filter replacement and proceed to drain plug installation. Note: Some ZF 6HP26 variants have lifetime internal filters not intended for routine service.
   ℹ️Forcing removal of a non-serviceable pan can cause damage. Consult service documentation if pan design is unclear.
5. 5

   Remove transmission pan (if serviceable)
   If the transmission pan is removable, carefully remove the pan bolts in a criss-cross pattern using the appropriate Torx socket. Loosen all bolts several turns before removing any completely to prevent pan distortion. Once bolts are removed, carefully pry the pan loose, being aware that residual fluid (approximately 1-2 quarts) will spill. Have drain pan positioned to catch this fluid. Lower the pan and pour remaining fluid into drain pan.
   Torque spec

   Transmission Pan Bolts12 Nm (9 lb-ft)
6. 6

   Replace transmission filter (if accessible)
   On the ZF 6HP26 the filter is integrated into the oil pan assembly, so there is no separate bolt-on filter to remove from the valve body. The filter is replaced together with the pan as a single unit. Discard the old pan/filter assembly and prepare the new pan/filter unit for installation, verifying it matches the OEM specification for this application. Because the filter is integrated into the pan on the ZF 6HP26, there are no separate filter mounting bolts to install; simply proceed to installing the new pan/filter assembly in the next step.
   Torque spec

   Transmission Filter Bolts8 Nm (6 lb-ft)
7. 7

   Clean and reinstall transmission pan (if removed)
   Thoroughly clean the transmission pan interior, removing all sludge, metal particles, and old gasket material. Clean the transmission case mating surface with a clean shop towel, ensuring no debris or old gasket material remains. Inspect the pan magnet (if equipped) and clean thoroughly. Install the new pan/gasket unit; note the ZF 6HP26 pan gasket is typically bonded to the replacement pan assembly rather than supplied as a separate gasket, so verify gasket type before assembly. Position the pan and hand-start all bolts before tightening. Tighten pan bolts in a criss-cross pattern to specification to ensure even gasket compression.
   Torque spec

   Transmission Pan Bolts12 Nm (9 lb-ft)
8. 8

   Install drain plug
   Clean the drain plug hole threads in the transmission pan or case. Thread the drain plug with new crush washer into the transmission by hand to ensure proper thread engagement. Once hand-tight, use a torque wrench and appropriate socket to tighten the drain plug to specification. Do not overtighten as this can strip the aluminum transmission case threads.
   Torque spec

   Transmission Drain Plug35 Nm (26 lb-ft)
9. 9

   Refill transmission with fluid
   Locate the transmission fill plug on the side of the transmission case or the dipstick tube if equipped. The ZF 6HP26 uses a side-mounted overflow fill/level plug and requires a fluid pump for filling; this transmission has no dipstick. Using a fluid pump with extension tube, add ZF-approved ATF meeting the ZF Lifeguard 6 (Shell M-1375.4 / Aston Martin OEM) specification. For a pan-drop drain-and-fill, add approximately the amount drained (typically 4-5 quarts) and then set final level using the temperature-dependent level-check procedure; do not simply add the full 9.5 quart dry-fill capacity. If using the level-check (overflow plug) method, the level must be set with the engine running and transmission fluid at the specified temperature window (typically ~30-40°C per ZF/OEM spec); add fluid until it just begins to trickle from the level plug at that temperature, then install the plug. A scan tool to monitor fluid temperature is strongly recommended. Refer to service documentation for exact fill procedure for this transmission variant. Note: Using a fluid pump with extension tube or funnel with long extension, add fluid through the fill point. Note that a pan-drop drain-and-fill typically only replaces approximately 4-5 quarts (full dry-fill capacity is near 9.5 quarts), so add ZF LifeguardFluid 6 (Shell M-1375.4 spec ATF) until it reaches the correct level per the fill procedure. Note: The ZF 6HP26 requires the fluid temperature to be within approximately 30-40°C during the overflow level check, and a scan tool is required to monitor transmission fluid temperature for a correct fill. Note: Using a fluid pump with extension tube, add fluid equal to the amount drained (typically approximately 4-5 quarts for a pan drop, or refer to OEM documentation for exact fill) of the ZF-approved ATF specified for the ZF 6HP26 (per Aston Martin specification) through the fill point. Do not assume full dry-fill capacity on a service refill.
   ℹ️Some ZF transmissions require fluid temperature to be within specific range (30-50°C) during level check. A scan tool may be needed for precise fill procedure.
10. 10

    Check fluid level and cycle transmission
    With the transmission filled, start the engine and allow it to idle. With the parking brake engaged and foot on brake pedal, shift through all gear positions (P-R-N-D-S and back to P), pausing 2-3 seconds in each position. This circulates fluid through all circuits. Return to Park and check the fluid level using the overflow fill-plug method with the fluid temperature monitored by scan tool (approximately 30-40°C). With the vehicle level and engine running, open the fill/level plug; fluid should just trickle out at the correct temperature. Add fluid as necessary and reinstall the plug while fluid is within the specified temperature range. Note: Check the level using the overflow-plug method at the specified fluid temperature; this transmission does not use a conventional dipstick, so set the level per the temperature-dependent overflow procedure rather than a cold/hot dipstick range.
11. 11

    Reinstall undertray and lower vehicle
    Reinstall the engine/transmission undertray, ensuring all clips and fasteners are properly engaged. Tighten undertray fasteners securely but do not overtighten plastic clips. Verify no tools or materials were left in the engine bay or under the vehicle. Carefully lower the vehicle to the ground.

Reassembly

1. Ensure all fasteners are tightened to specification and no fluid leaks are present at the drain plug or pan gasket.
2. Double-check that the fill plug or dipstick is properly seated after final fluid level check.
3. Dispose of used transmission fluid and filter according to local environmental regulations.

Verification

• Start the engine and check for leaks around the drain plug and transmission pan (if removed) while engine idles.
• With engine at operating temperature, perform a final fluid level check using the appropriate method for this transmission.
• Test drive the vehicle and verify smooth shifting through all gears with no slipping, harsh engagements, or delayed shifts.
• After test drive, recheck fluid level and inspect for leaks. Top off fluid if necessary.
• Monitor transmission operation over the next several days to ensure proper function and no leaks develop.

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