🔧 Highlander - Automatic Transmission Fluid Drain and Fill

Changing the transmission fluid on your Highlander is a drain-and-fill service, not a full flush. This replaces part of the automatic transmission fluid and helps keep shifting smooth while reducing wear inside the transmission.

Difficulty Level: Intermediate | Estimated Time: 1.5-2.5 hours

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⚠️ Safety & Precautions

• ⚠️ Work on a cool or mildly warm vehicle only. Hot automatic transmission fluid can burn skin.
• ⚠️ Keep your Highlander level during filling and final level checking.
• ⚠️ Never crawl under a vehicle supported only by a jack. Use jack stands.
• ⚠️ Use only Toyota WS-compatible automatic transmission fluid. The wrong fluid can cause shift problems or transmission damage.
• ⚠️ 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
• 10mm socket
• 14mm socket
• 24mm socket
• 3/8-inch drive ratchet
• 1/2-inch drive ratchet
• Torque wrench 5-80 Nm
• Drain pan 8-quart minimum
• Fluid transfer pump
• Measuring container marked in quarts
• Infrared thermometer
• OBD scan tool with live transmission temperature (specialty)
• Shop towels

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Toyota WS-compatible automatic transmission fluid - Qty: 4 quarts
• Transmission drain plug gasket - Qty: 1
• Transmission fill plug gasket - Qty: 1

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📋 Before You Begin

• 🅿️ Park your Highlander on level ground and set the parking brake.
• 🛞 Place wheel chocks behind the rear wheels.
• 🌡️ For the most accurate level check, use an OBD scan tool with live transmission temperature. This means the tool can read the fluid temperature from the vehicle computer.
• 🧪 Measure the amount of old fluid drained. Refill with the same amount first, then fine-tune the level.
• 📌 Assumption: This procedure covers a standard drain-and-fill service on the 6-speed automatic transmission used with your Highlander.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Raise and Support the Vehicle

• Use a floor jack rated 3-ton minimum to lift the front of your Highlander at the front center jacking point.
• Place jack stands rated 3-ton minimum under the proper front support points.
• Lower the vehicle gently onto the jack stands.
• Use the floor jack to raise the rear if needed, then support it with jack stands so the vehicle sits level.
• Use a small level or visual check to make sure the vehicle is not nose-up or nose-down.

Step 2: Remove the Lower Splash Shield

• Put on safety glasses and nitrile gloves.
• Use a 10mm socket and 3/8-inch drive ratchet to remove the lower splash shield bolts.
• Use a trim clip removal tool if any plastic clips are fitted.
• Set the shield and fasteners aside in order.
• Take photos before removing panels.

Step 3: Locate the Transmission Fill and Drain Plugs

• Use a flashlight to find the automatic transmission case on the driver side area of the powertrain.
• Identify the fill plug on the side of the transmission case.
• Identify the drain plug on the lower part of the transmission pan area.
• Always remove the fill plug first. This confirms you can refill the transmission before draining it.

Step 4: Remove the Fill Plug First

• Place the drain pan under the transmission area.
• Use a 24mm socket and 1/2-inch drive ratchet to loosen and remove the fill plug.
• Remove the old fill plug gasket.
• If the fill plug will not loosen, stop. Do not drain the fluid.

Step 5: Drain the Old Transmission Fluid

• Move the drain pan directly under the transmission drain plug.
• Use a 14mm socket and 3/8-inch drive ratchet to remove the drain plug.
• Let the fluid drain until it slows to a drip.
• Measure the drained fluid using a measuring container marked in quarts.
• Typical drain amount is about 2.5-3.5 quarts, but use your measured amount as the starting refill amount.

Step 6: Reinstall the Drain Plug

• Wipe the drain plug with shop towels.
• Install a new transmission drain plug gasket on the drain plug.
• Thread the drain plug in by hand first to avoid cross-threading.
• Use a 14mm socket and torque wrench to tighten the drain plug to Torque to 49 Nm (36 ft-lbs).

Step 7: Refill the Transmission

• Use a fluid transfer pump to pump Toyota WS-compatible automatic transmission fluid into the fill opening.
• Add the same amount of fluid that came out.
• Install the fill plug finger-tight for now using the old plug position only as a temporary seal.
• Do not fully torque the fill plug yet.

Step 8: Warm the Fluid and Circulate It

• Connect the OBD scan tool with live transmission temperature.
• Start the engine with your foot on the brake.
• Move the shifter slowly through P, R, N, D, then back to P.
• Pause 3 seconds in each gear position.
• Keep the engine idling during the level check.

Step 9: Check Fluid Temperature

• Use the OBD scan tool to monitor automatic transmission fluid temperature.
• Begin the final level check when fluid temperature is approximately 40-45°C (104-113°F).
• If you do not have scan-tool temperature, use an infrared thermometer on the transmission pan as a less accurate backup.
• Do not overheat the fluid during the check. Let it cool if needed.

Step 10: Final Fluid Level Check

• With the engine idling and your Highlander level, remove the fill plug using a 24mm socket and 1/2-inch drive ratchet.
• If no fluid comes out, use the fluid transfer pump to add fluid in small amounts until fluid begins to trickle from the fill opening.
• If fluid pours out heavily, let it drain until it becomes a small steady trickle.
• The correct level is reached when fluid just trickles from the fill opening at the correct temperature.

Step 11: Install and Torque the Fill Plug

• Turn the engine OFF after the level is set.
• Install a new transmission fill plug gasket on the fill plug.
• Thread the fill plug in by hand first.
• Use a 24mm socket and torque wrench to tighten the fill plug to Torque to 39 Nm (29 ft-lbs).

Step 12: Reinstall the Splash Shield

• Use your hands to position the lower splash shield.
• Use a 10mm socket and 3/8-inch drive ratchet to reinstall the bolts.
• Tighten small splash shield bolts snugly by hand with the ratchet.
• Do not overtighten plastic shield fasteners.

Step 13: Lower the Vehicle

• Use the floor jack to lift your Highlander slightly off the jack stands.
• Remove the jack stands.
• Lower the vehicle slowly to the ground.
• Remove the wheel chocks after the vehicle is fully on the ground.

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✅ After Repair

• ✅ Start the engine and check for leaks around the drain plug and fill plug.
• ✅ Road test for 10-15 minutes with gentle acceleration.
• ✅ Confirm smooth shifts from a stop and during light cruising.
• ✅ Recheck underneath for leaks after the road test.
• ✅ Dispose of old transmission fluid at a recycling center or auto parts store that accepts used fluid.

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💰 DIY vs Shop Cost

Shop Cost: $180-$320 (parts + labor)

DIY Cost: $45-$90 (parts only)

You Save: $135-$230 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.0-1.5 hours.

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🎯 Ready to get started?

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