🔧 Odyssey - Automatic Transmission Fluid Change

This service replaces the automatic transmission fluid in your Odyssey to help maintain smooth shifting and protect the 9-speed automatic transmission. This is a drain-and-fill service, not a power flush.

Difficulty Level: Beginner | Estimated Time: 1-2 hours

Assumption: This procedure is for the stock 9-speed automatic transmission used on your Odyssey EX.

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⚠️ Safety & Precautions

• ⚠️ Work on a level surface so the fluid level is accurate.
• ⚠️ Transmission fluid can be hot. Let the vehicle cool if it was recently driven.
• ⚠️ Always support your Odyssey with jack stands. Never rely on a floor jack alone.
• ⚠️ Keep dirt out of the fill opening. Even small debris can damage the transmission.
• ⚠️ Do not power-flush this transmission. Use a drain-and-fill method only.
• ⚠️ Battery disconnect is not required for this service.

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🔧 Required Tools

You'll need the following tools for this repair:

• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks
• Safety glasses
• Nitrile gloves
• 3/8-inch drive ratchet
• 10mm socket
• Phillips screwdriver
• Flat trim clip remover
• Torque wrench 3/8-inch drive
• Fluid drain pan 8-quart minimum
• Long-neck funnel
• Clean measuring container 5-quart minimum
• Clean shop towels
• Scan tool with transmission fluid temperature data (specialty)

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Honda ATF Type 3.1 automatic transmission fluid - Qty: 4 quarts
• Transmission drain plug sealing washer - Qty: 1
• Replacement splash shield clips - Qty: 4

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📋 Before You Begin

• Park your Odyssey on level ground and set the parking brake.
• Chock the rear wheels with wheel chocks so the van cannot roll.
• Warm the transmission slightly with a short drive, then let it sit a few minutes so the fluid is warm but not burning hot.
• A scan tool is recommended because the final fluid level is checked with the transmission fluid at the correct temperature. A scan tool reads live data from the vehicle computers.
• Do not mix fluid types. Use Honda ATF Type 3.1 only for this 9-speed transmission.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Raise and Support the Front

• Use the wheel chocks behind the rear wheels.
• Use the floor jack to lift the front of your Odyssey at the front center jacking point.
• Place jack stands under the approved front support points.
• Gently lower the vehicle onto the jack stands.
• Give the vehicle a light push by hand to confirm it is stable.
• Never crawl under an unsupported vehicle.

Step 2: Remove the Lower Splash Shield

• Put on safety glasses and nitrile gloves.
• Use a 10mm socket to remove the splash shield bolts.
• Use a Phillips screwdriver to remove any screw-style retainers.
• Use a flat trim clip remover to remove plastic push clips. A trim clip remover is a small pry tool that removes plastic clips without breaking them.
• Set the splash shield aside.

Step 3: Locate the Transmission Drain Plug

• Slide the fluid drain pan under the transmission case.
• Find the transmission drain plug at the bottom of the transmission housing.
• Clean around the drain plug with clean shop towels before removing it.
• Clean first so dirt cannot enter.

Step 4: Drain the Old Fluid

• Use a 3/8-inch drive ratchet to loosen and remove the transmission drain plug.
• Let the fluid drain fully into the fluid drain pan.
• This may take several minutes.
• Inspect the drain plug for heavy metal debris. A light gray paste on the magnet is normal.

Step 5: Reinstall the Drain Plug

• Remove the old sealing washer from the drain plug by hand.
• Install a new transmission drain plug sealing washer.
• Thread the drain plug in by hand first to avoid cross-threading.
• Use a torque wrench 3/8-inch drive to tighten the drain plug to Torque to 49 Nm (36 ft-lbs).

Step 6: Measure the Drained Fluid

• Carefully pour the old fluid from the drain pan into a clean measuring container.
• Record the amount removed.
• Use this amount as your starting refill amount.
• Most drain-and-fill services remove about 3-4 quarts, but always measure what came out.

Step 7: Refill the Transmission

• Open the transmission fill point from the top side of the engine bay.
• Use a long-neck funnel to add Honda ATF Type 3.1 automatic transmission fluid.
• Add the same amount that drained out first.
• Add fluid slowly to avoid spills.
• Reinstall the fill cap or fill plug securely by hand.
• Do not overfill the transmission.

Step 8: Circulate the New Fluid

• Start the engine with your foot on the brake.
• Use the gear selector to slowly move through each gear position.
• Pause for 3 seconds in each position.
• Return the shifter to Park.
• Leave the engine idling during the fluid level check.

Step 9: Check Transmission Fluid Temperature

• Connect the scan tool with transmission fluid temperature data to the diagnostic port under the driver side dash.
• Read the transmission fluid temperature on the scan tool.
• Check the level when the fluid is in the service temperature range shown by the scan tool.
• If the scan tool cannot read transmission fluid temperature, do not guess the final level. Have the level verified with the correct scan data.

Step 10: Verify Final Fluid Level

• With the engine idling and the vehicle level, inspect the transmission level according to the factory check method.
• If fluid is low, use the long-neck funnel to add small amounts of Honda ATF Type 3.1 automatic transmission fluid.
• If fluid is overfilled, drain a small amount using the 3/8-inch drive ratchet at the drain plug, then reinstall and torque the plug again to Torque to 49 Nm (36 ft-lbs).
• Wipe all spilled fluid with clean shop towels.

Step 11: Reinstall the Lower Splash Shield

• Raise the splash shield back into place.
• Use the flat trim clip remover by hand to position the clips, then press the clips into place.
• Use the Phillips screwdriver to reinstall screw-style retainers.
• Use the 10mm socket to reinstall the splash shield bolts.
• Tighten splash shield fasteners snug only; do not overtighten plastic parts.

Step 12: Lower the Vehicle

• Use the floor jack to lift your Odyssey slightly off the jack stands.
• Remove the jack stands.
• Lower the vehicle slowly to the ground with the floor jack.
• Remove the wheel chocks.

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✅ After Repair

• Test drive your Odyssey for 10-15 minutes on local roads.
• Check for smooth engagement from Park to Drive and Reverse.
• Recheck under the vehicle for leaks around the drain plug.
• If shifting feels harsh, delayed, or a warning light appears, stop driving and scan for transmission codes.
• Dispose of used transmission fluid at an auto parts store, recycling center, or service shop that accepts waste oil.

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💰 DIY vs Shop Cost

Shop Cost: $180-$350 (parts + labor)

DIY Cost: $55-$110 (parts only)

You Save: $125-$240 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1-1.5 hours.

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