how do you change transmission oil in a manual transmission

Warm up the car, remove the fill plug first, then the drain plug, let the old gear oil drain out, reinstall the drain plug, and pump in the exact manual-transmission fluid your car calls for until it reaches the bottom of the fill hole. The big things are using the right fluid, keeping the car level, and not draining it unless you know you can get the fill plug back out.

Key takeaways

• Always open the fill plug before draining, so you do not get stuck with an empty gearbox you cannot refill.
• Use the exact fluid spec in the owner’s manual or service manual, not just any gear oil.
• Keep the vehicle level on jack stands or ramps so the fill level is correct.
• Replace crush washers or sealing washers if your plugs use them, and tighten to spec.

Deeper dive

On most manuals, you drive a few minutes to warm the fluid, park level, raise and support the car safely, then locate the transmission fill and drain plugs. Crack the fill plug loose first. Put a drain pan under the drain plug, remove it, and let it drain fully. Clean the plug, especially if it has a magnet, install a new washer if needed, and reinstall the drain plug. Pump in fresh fluid through the fill hole until it just starts to dribble out, then reinstall the fill plug. I’m assuming you mean a standard drain-and-fill, not a full teardown or flush.