The following covers Hyundai Sonata models from 1994 through 1998. Check and replace the automatic transmission fluid level at the 10,000 mile mark and every 20,000 miles thereafter, if you drive the car under normal driving conditions. If you drive the car under severe driving conditions, change the automatic transmission fluid every 15,000 miles.
Raise the front of the Sonata with ramps or a floor jack. Safely support it with jack stands and wheel blocks. Place a drain pan beneath the transmission drain plug. Use a ratchet or socket wrench, whichever is most appropriate, to remove the drain plug. Wait for the fluid to stop draining.
Loosen the retaining bolts on the transmission fluid pan with a socket wrench. Gently tap the side of the pan with a rubber mallet to break the seal. Support the pan with one hand while you remove the bolts completely. Carefully lift the pan to drain the remaining fluid from the pan.
Check the fluid filter for clogs or damage. Replace the filter if necessary. Clean the pan, gasket and gasket surfaces with a safe solvent and allow them to air dry. Replace the pan and gasket to their original positions. Ensure the bolt holes line up and reinstall the retaining bolts. Progressively tighten the bolts in a criss cross fashion to 7 1/2 to 8 1/2 foot pounds with a torque wrench.
Replace the drain plug and tighten it to 22 to 25 foot pounds. Lower the car and make sure it's on level ground.
Remove the transmission fluid dipstick and replace it with a funnel. Alternate adding small amounts of fresh automatic transmission fluid and checking the fluid level until the fluid level reaches the lower mark on the dipstick. Hyundai recommends the use of Mopar ATF Plus Type 7176 or its equivalent.
Start the engine, let it idle for 2 to 3 minutes and check the fluid level again. Add more transmission fluid if necessary. When the fluid level reaches the appropriate position on the dipstick, replace the dipstick, close the hood and turn off the engine.
