🔧 Impala - Transmission Fluid Drain and Refill

Your Impala uses a sealed 6T70 six-speed automatic transmission. This procedure drains the old fluid, refills with GM-approved DEXRON-VI fluid, and sets the final level while the transmission is running at the specified temperature.

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

Assumption: This procedure is for routine fluid maintenance without transmission leaks or internal faults.

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⚠️ Safety & Precautions

• ⚠️ Support your Impala on four jack stands. The vehicle must remain level for an accurate fluid check.
• ⚠️ Never work beneath a vehicle supported only by a floor jack.
• ⚠️ Transmission fluid and nearby exhaust components can cause severe burns.
• ⚠️ Keep hands, clothing, and tools away from moving components while the engine is running.
• ⚠️ Do not use DEXRON-III, universal CVT fluid, or DCT fluid. Use only licensed DEXRON-VI automatic transmission fluid.
• ⚠️ Do not perform a pressurized transmission flush as part of this service.
• ⚠️ The battery does not need to be disconnected.

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🔧 Required Tools

You'll need the following tools for this repair:

• Hydraulic floor jack rated 2-ton minimum
• Four jack stands rated 2-ton minimum
• Two wheel chocks
• 10mm socket
• 11mm socket
• 3/8-inch-drive ratchet
• 3/8-inch-drive torque wrench rated 5-50 Nm
• OBD-II scan tool with transmission-fluid-temperature data (specialty)
• Long transmission-fluid funnel
• Graduated 8-quart drain pan
• Fluid measuring container marked in 100ml increments
• Plastic trim removal tool
• Mechanic's creeper
• LED work light
• Nitrile mechanic gloves
• Safety glasses
• Shop towels

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Licensed DEXRON-VI automatic transmission fluid - Qty: 6 quarts
• Transmission drain-plug sealing washer - Qty: 1
• Transmission level-plug sealing washer - Qty: 1

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📋 Before You Begin

• Park your Impala on firm, level pavement and apply the parking brake.
• Use the OBD-II scan tool to check for transmission fault codes before beginning. Record any codes instead of clearing them.
• The transmission has no conventional dipstick. Its level is checked through a level plug while the engine runs.
• A scan tool is required because the final fluid level must be checked at the correct transmission-fluid temperature.
• If the old fluid contains metal fragments, smells severely burned, or has a milky appearance, stop and have the transmission inspected.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Warm and Inspect the Transmission

• Use the OBD-II scan tool to verify that transmission-fluid temperature is warm enough for the fluid to drain easily, approximately 30-50°C (86-122°F).
• Use the LED work light to inspect beneath your Impala for fluid leaks before removing any plugs.
• Switch off the engine before raising the vehicle.

Step 2: Raise the Vehicle Level

• Place the two wheel chocks around a wheel that remains on the ground during initial lifting.
• Use the hydraulic floor jack at the approved front and rear lifting points.
• Place all four jack stands beneath the approved support points so your Impala sits level.
• Gently test stability before going underneath. Keep the floor jack clear of the work area.
• Match all four stand heights carefully.

Step 3: Remove the Lower Splash Shield

• Put on the safety glasses and nitrile mechanic gloves.
• Use the 10mm socket and 3/8-inch-drive ratchet to remove the splash-shield fasteners that block access to the transmission.
• Use the plastic trim removal tool to release any plastic retainers without breaking them.
• Support the shield by hand while removing its final fastener.

Step 4: Confirm the Fill Plug Opens

• Use the LED work light to locate the transmission fill cap on top of the transmission, below the air-intake area.
• Loosen the fill cap by hand before draining the transmission. This ensures the transmission can be refilled.
• Use shop towels to clean dirt from around the cap before removing it.

Step 5: Drain the Old Fluid

• Position the graduated 8-quart drain pan directly beneath the transmission drain plug.
• Use the 11mm socket and 3/8-inch-drive ratchet to loosen the drain plug slowly.
• Remove the plug by hand while keeping the drain pan centered beneath it.
• Allow the fluid to drain until it slows to an occasional drip.
• Use the fluid measuring container to record the amount removed. A normal drain commonly removes approximately 4.5-5.5 quarts, but the measured amount and final level check control the refill.

Step 6: Inspect and Install the Drain Plug

• Use shop towels to clean the drain plug and inspect it for damaged threads or excessive metal debris.
• Install a new transmission drain-plug sealing washer.
• Start the drain plug by hand to prevent cross-threading.
• Use the 11mm socket and 3/8-inch-drive torque wrench to tighten the plug to 12 Nm (106 in-lbs).
• Do not overtighten the plug because the transmission case is aluminum.

Step 7: Add the Initial Refill

• Insert the long transmission-fluid funnel into the fill opening.
• Add licensed DEXRON-VI fluid equal to approximately the amount removed, stopping about 0.5 quart short of that amount.
• Use the fluid measuring container to measure the refill accurately.
• Install the fill cap by hand so dirt cannot enter during the temperature check.
• Add slowly to prevent funnel overflow.

Step 8: Circulate the New Fluid

• Connect the OBD-II scan tool and display transmission-fluid temperature.
• Start the engine with the parking brake applied and keep your foot firmly on the brake pedal.
• Move the selector slowly through Park, Reverse, Neutral, Drive, and Low, pausing approximately three seconds in each position.
• Return the selector to Park and leave the engine idling.
• Use the LED work light to inspect the drain plug for leakage.

Step 9: Bring the Fluid to Checking Temperature

• Use the OBD-II scan tool to monitor transmission-fluid temperature while the engine idles.
• Proceed with the final check when the temperature reaches 85-95°C (185-203°F).
• Keep your Impala level, the engine idling, and the selector in Park throughout the check.
• Do not allow the temperature to exceed the checking range. If it does, reinstall the plug and let the transmission cool before repeating the check.

Step 10: Set the Final Fluid Level

• Wear safety glasses and nitrile mechanic gloves because the fluid and exhaust will be hot.
• Place the graduated 8-quart drain pan beneath the transmission level plug.
• Use the 11mm socket and 3/8-inch-drive ratchet to remove the level plug while the engine continues idling.
• If no fluid exits, install the long transmission-fluid funnel and add DEXRON-VI fluid in 0.25-quart increments until fluid begins to flow from the level opening.
• If fluid pours out in a steady stream, allow the excess to drain until it becomes a thin trickle or slow drip.
• Install a new level-plug sealing washer and start the plug by hand.
• Use the 11mm socket and 3/8-inch-drive torque wrench to tighten the level plug to 12 Nm (106 in-lbs).
• Reinstall the fill cap securely by hand.

Step 11: Reinstall the Splash Shield

• Switch off the engine and remove the OBD-II scan tool.
• Use the plastic trim removal tool to reinstall the plastic retainers.
• Use the 10mm socket and 3/8-inch-drive ratchet to reinstall the splash-shield fasteners until snug.
• Do not overtighten fasteners installed into plastic retainers.

Step 12: Lower the Vehicle

• Use the hydraulic floor jack to lift your Impala slightly from each pair of jack stands.
• Remove all four jack stands and lower the vehicle carefully.
• Remove the two wheel chocks only after the vehicle is fully on the ground.

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✅ After Repair

• ✅ Start the engine and verify smooth engagement in Reverse and Drive.
• ✅ Take a gentle 10-15 minute drive. Check that shifts remain smooth and no warning messages appear.
• ✅ Park on clean, level pavement and inspect beneath the transmission for leaks.
• ✅ Recheck for transmission fault codes with the OBD-II scan tool.
• ✅ Dispose of the used fluid through an authorized automotive-fluid recycling facility. Do not pour it onto the ground or into a drain.
• ✅ A drain and refill replaces only part of the transmission's total fluid. Do not add the full dry capacity.

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💰 DIY vs Shop Cost

Shop Cost: ₹9,000-₹16,000 (parts + labor)

DIY Cost: ₹4,500-₹7,500 (parts only)

You Save: ₹4,500-₹8,500 by doing it yourself!

Local labor rates vary. This repair takes a shop approximately 1-1.5 hours.

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🎯 Ready to get started?

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