Check your vehicle’s manual for the correct transmission fluid type, specification, and capacity
Park on a level surface, set the parking brake, and block the wheels
Warm the engine per the manual’s instructions (some transmissions require operating temperature)
Locate the transmission fill plug and drain plug (or pan drain procedure)
Gather tools and supplies: correct fluid, new filter/gasket if required, drain pan, funnel, sockets/wrenches, gloves, shop towels
Wear gloves and eye protection
Place the drain pan under the drain plug
Remove the drain plug and allow fluid to drain completely
Remove the transmission pan if the procedure requires a filter replacement or gasket replacement
Remove old gasket material and inspect the pan for debris or metal shavings
Replace or reinstall the filter if applicable
Install a new pan gasket (or torque with the specified gasket condition)
Reinstall the pan and tighten bolts to the specified torque pattern
Reinstall the drain plug with a new sealing washer if required and tighten to spec
Add new fluid through the fill opening using a funnel
If the vehicle has a dipstick, add fluid in small amounts and keep checking
If the vehicle has a fill plug procedure, fill until fluid starts to run out of the correct fill port (per manual)
Start the engine and shift through all gear positions, pausing as specified, then return to Park (or Neutral as specified)
Re-check fluid level per the manual’s temperature and method (dipstick vs fill plug)
Adjust fluid level by adding or draining small amounts until correct
Reinstall the dipstick (if equipped) or fill plug (if equipped)
Check for leaks around the drain plug and pan
Dispose of used fluid properly
Record the date, mileage, fluid type, and any service parts replaced