How to change your transmission fluid

Checking and adding fluid to your car’s transmission

A low fluid level can cause shifting an drive problems or premature failure of an automatic transmission. Check the transmission-fluid level once a month. After you’ve driven the car a few miles to warm up the fluid, stop on level ground, put the shift lever into Park and, with the engine running, pull out the transmission dipstick (on a Honda, shut off the engine and immediately pull the dipstick). The fluid level should be between the Add and Full marks. If it’s at or below Add, shut off the engine and add enough fluid to bring it to Full.

Automatic transmission fluid is sold in quart cans, but in most cases the amount needed will be subs tan-daily less. Don’t simply use the whole can; overfilling can also cause problems. Cap the can with a plastic lid or foil wrap to keep out dirt; save it. Pour the fluid into the dipstick tube. Use a special long-necked funnel sold in auto parts stores.

Types of fluid

Use only the fluid formulated for your transmission; otherwise shift problems can result. Most cars use Dexron II fluid. Exceptions are Mazda, Volvo, and certain Fords that use Type F. Other Fords use Dexron or Type H. If you own a Ford, check with a dealer to find out which fluid your transmission requires. Dexron and Type F are readily available, but Type H may be available only from a dealer.

If the transmission requires fluid every few months, have it checked for leaks. Smell the dipstick and compare the odor with fresh fluid. If the dipstick sample is discolored or smells burned, the transmission may soon need repair.