🔧 Regal - Automatic Transmission Fluid Drain & Fill

This is a “drain-and-fill” service (not a full flush). You’ll drain the old fluid, refill with the correct spec fluid, then set the final fluid level at the correct transmission temperature so shifting and lubrication stay correct.

Difficulty Level: Intermediate | Estimated Time: 1.5-3 hours

---

⚠️ Safety & Precautions

• 🧯 Work on level ground and support the car on jack stands, not a jack.
• 🔥 Transmission fluid can be hot; let the car cool if you just drove it.
• 🧤 Wear nitrile gloves and safety glasses; ATF is slippery and irritating.
• ⚠️ Keep the car level during filling and level-checking, or the fluid level will be wrong.

---

🔧 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
• Drain pan (10-quart minimum)
• Shop rags
• Torque wrench (10–80 Nm range)
• Ratchet
• 10mm socket
• 13mm socket
• Torx T30 bit
• 8mm hex bit socket
• Fluid transfer pump (specialty)
• OBD-II scan tool with live data (specialty)
• Infrared thermometer

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Automatic transmission fluid (GM AW-1 spec) - Qty: 5 quarts
• Drain/fill plug sealing washers - Qty: 2
• Brake cleaner - Qty: 1

---

📋 Before You Begin

• 🧭 Park on a flat, level surface, set the parking brake, and place wheel chocks behind the rear wheels.
• Lift the front with a floor jack and support with jack stands. Keep the car as level as possible (best practice: raise/support all four corners).
• Have your fluid transfer pump ready. This tool pumps new ATF into the fill port (you can’t pour it in easily from above).
• Assumption: Your Regal uses the common AWD 6-speed automatic with a temperature-based level check; steps below follow that style.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the lower splash shield (if equipped)

• Use a 10mm socket and Torx T30 bit to remove the fasteners.
• Set the shield and hardware aside in a small pile so nothing gets lost.

Step 2: Locate the transmission plugs

• Find the transmission case and identify the fill plug, drain plug, and level/check plug.
• Use an 8mm hex bit socket where applicable (an “hex bit socket” is an Allen-key shaped bit that fits on a ratchet).
• Tip: Always loosen the fill plug first.

Step 3: Loosen the fill plug first

• Place a drain pan underneath (some fluid may drip).
• Use a ratchet with the correct socket/bit (often 8mm hex bit socket) to crack the fill plug loose.
• If the fill plug will not loosen, stop here (you don’t want an empty transmission you can’t refill).

Step 4: Drain the old transmission fluid

• Position your drain pan under the drain plug.
• Remove the drain plug using a ratchet and correct socket/bit (often 8mm hex bit socket).
• Let it drain until it slows to an occasional drip (usually 10–20 minutes).
• Clean the plug area with shop rags and brake cleaner.

Step 5: Reinstall the drain plug

• Install a new sealing washer on the drain plug.
• Thread it in by hand first to avoid cross-threading.
• Use a torque wrench to tighten: Torque to 35 Nm (26 ft-lbs).

Step 6: Fill with new transmission fluid

• Insert the hose from the fluid transfer pump (specialty) into the fill port.
• Pump in GM AW-1 spec ATF until you’ve added about what drained out (commonly ~4 quarts on a drain-and-fill).
• Reinstall the fill plug finger-tight for now (you may need to reopen it after level-checking).

Step 7: Warm the transmission and circulate fluid

• Start the engine with the car still safely supported on jack stands.
• Hold the brake and move the shifter slowly through P-R-N-D and back, pausing 2–3 seconds in each gear.
• Use an OBD-II scan tool with live data (specialty) to monitor transmission fluid temperature (this plugs into the diagnostic port and shows sensor data).
• If you don’t have live data, use an infrared thermometer on the transmission pan as a rough guide (less accurate).

Step 8: Set the final fluid level (temperature-based check)

• With the engine idling and the car level, bring fluid temperature to about 35–45°C (95–113°F).
• Place the drain pan under the level/check plug.
• Remove the level/check plug using the ratchet and correct socket/bit.
• Correct level behavior:
  • If fluid dribbles out in a thin stream, the level is OK. Let it reduce to a drip.
  • If no fluid comes out, add fluid through the fill port using the fluid transfer pump (specialty) until it just starts to dribble from the level port.
• Reinstall the level/check plug and tighten with a torque wrench: Torque to 35 Nm (26 ft-lbs).
• Tighten the fill plug with a torque wrench: Torque to 35 Nm (26 ft-lbs).

Step 9: Reinstall the splash shield

• Reinstall the shield using the 10mm socket and Torx T30 bit.
• Snug fasteners evenly (do not over-tighten). If you use a torque wrench: Torque to 10 Nm (89 in-lbs).

---

✅ After Repair

• 🧼 Wipe everything clean, then run the engine and check for leaks around the drain, level, and fill plugs.
• 🚗 Road test 10–15 minutes. Verify smooth shifting and no slipping.
• 🔎 Recheck for leaks after the drive. If you notice delayed engagement or flare shifts, the level may be off and should be rechecked at temperature.
• Tip: Dispose of used ATF at a recycling center.

---

💰 DIY vs Shop Cost

Shop Cost: $250-$450 (parts + labor)

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

You Save: $160-$405 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5-2.5 hours.

---

🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.