Both the automatic and manual transmissions covered by this information use Mercon® automatic transmission fluid for lubrication. DO NOT use improper fluids such as Dexron® or gear oil. Use of improper fluids could lead to leaks or transmission damage.
On automatic transmissions the fluid type is normally stamped on the dipstick. Be sure to double check the dipstick before adding any fluid.
See Figures 1, 2, 3 and 4
It is very important to maintain the proper fluid level in an automatic transmission. If the level is either too high or too low, poor shifting operation and internal damage are likely to occur. For this reason, a regular check of the fluid level is essential.
Although it is best to check fluid at normal operating temperature, it can be checked overnight cold, if the ambient temperatures are 50-95°F (21-35°C). If so, refer to the dots on the transmission dipstick instead of the cross-hatched area and level marking lines.
- Drive the vehicle for 15-20 minutes allowing the transmission to reach operating temperature.
If the car is driven at extended highway speeds, is driven in city traffic in hot weather or is being used to pull a trailer, fluid temperatures will likely exceed normal operating and checking ranges. In these circumstances, give the fluid time to cool (about 30 minutes) before checking the level.
- Park the car on a level surface, apply the parking brake and leave the engine idling. Make sure the parking brake is FIRMLY ENGAGED. Shift the transmission and engage each gear, then place the selector in P (PARK).
- Open the hood and locate the transmission dipstick. Wipe away any dirt in the area of the dipstick to prevent it from falling into the filler tube. Withdraw the dipstick, wipe it with a clean, lint-free rag and reinsert it until it fully seats.
- Withdraw the dipstick and hold it horizontally while noting the fluid level. It should be between the upper (FULL) and the lower (ADD) marks.
- If the level is below the lower mark, use a funnel and add fluid in small quantities through the dipstick filler neck. Keep the engine running while adding fluid and check the level after each small amount. DO NOT overfill as this could lead to foaming and transmission damage or seal leaks.
See Figure 5
The fluid level should be checked every six months or 6000 miles (9600 km), whichever comes first.
- Park the car on a level surface, turn the engine OFF , FIRMLY apply the parking brake and block the drive wheels.
Ground clearance may make access to the transmission filler plug impossible without raising and supporting the vehicle, BUT if this is done the car MUST be supported at four corners and level. If only the front or rear is supported, an improper fluid level will be indicated. If you are going to place the car on four jackstands, this might be the perfect opportunity to rotate the tires as well.
- Remove the filler plug from the side of the transmission case using a 3 / 8 in. drive ratchet and extension. The fluid level should be even with the bottom of the filler hole.
- If additional fluid is necessary, add it through the filler hole using a siphon pump or squeeze bottle.
- When you are finished, carefully install the filler plug, but DO NOT overtighten it and damage the housing.
DRAIN AND REFILL
See Figures 6 through 18
Under normal service (moderate highway driving excluding excessive hot or cold conditions), the manufacturer feel that automatic transmission fluid should not need to be changed. However, if a major service is performed to the transmission, if transmission fluid becomes burnt or discolored through severe usage or if the vehicle is subjected to constant stop-and-go driving in hot weather, trailer towing, long periods of highway use at high speeds, fluid should be changed to prevent transmission damage. A preventive maintenance change is therefore recommended for most vehicles at least every 90,000 miles (145,000 km).
Although not a required service, transmission fluid changing can help assure a trouble-free transmission. Likewise, changing the transmission filter at this time is also added insurance.
- Raise the car and support it on jackstands.
The torque converters on some transmissions are equipped with drain plugs. Because it may take some time to drain the fluid from the converter, you may wish to follow that procedure at this time, then come back to the pan and filter removal.
- Place a drain pan under the transmission.
- Loosen all of the pan attaching bolts to within a few turns of complete removal, then carefully break the gasket seal allowing most of the fluid to drain.
- When fluid has drained to the level of the pan flange, remove the pan bolts and carefully lower the pan doing your best to drain the rest of the fluid into the drain pan.
- Clean the transmission oil pan thoroughly using a safe solvent, then allow it to air dry. DO NOT use a cloth to dry the pan which might leave behind bits of lint. Discard the old pan gasket.
- Loosen and remove the oil filter screen retaining bolts, then carefully lower the filter from the transmission. Make sure any gaskets or seals are removed with the old filter. The A4LD transmission usually has an O-ring for each of the tubes connecting the filter to the valve body, while the AOD transmission usually has one round seal and a rectangular gasket.
- Install the new oil filter screen making sure all gaskets or seals are in place, then secure using the retaining screws.
- Place a new gasket on the fluid pan, then install the pan to the transmission. Tighten the attaching bolts to 8-10 ft. lbs. (8-11 Nm) for the A4LD transmission or to 71-119 inch lbs. (8-13 Nm) for AOD transmissions.
- Add three quarts of fluid to the transmission through the filler tube.
- Remove the jackstands and carefully lower the vehicle.
- Start the engine and move the gear selector through the shift pattern. Allow the engine to reach normal operating temperature.
- Check the transmission fluid. Add fluid, as necessary to obtain the correct level.
Some torque converters, such as those usually used on the AOD transmission, are equipped with drain plugs, if so you will probably want to drain the fluid in the converter also at the time of a transmission pan fluid change. Just, make sure that you compensate for the additional fluid drained during the refilling process.
- Remove the lower engine dust cover.
- Rotate the torque converter until the drain plug comes into view.
- Remove the drain plug and allow the transmission fluid to drain. This could take some time, so you may wish to perform the other transmission service (fluid pan and filter removal) while waiting.
- Once the fluid has been drained, install the drain plug.
- Install the engine dust cover.
- Make sure the transmission is properly refilled with fluid before attempting to drive the vehicle.
See Figure 19
Under normal conditions, the manufacturer feels that manual transmission fluid should not need to be changed. However, if the car is driven in deep water (as high as the transmission casing) it is a good idea to replace the fluid. Little harm can come from a fluid change when you have just purchased a used vehicle, especially since the condition of the transmission fluid is usually not known.
If the fluid is to be drained, it is a good idea to warm the fluid first so it will flow better. This can be accomplished by 15-20 miles of highway driving. Fluid which is warmed to normal operating temperature will flow faster, drain more completely and remove more contaminants from the housing.
- Drive the vehicle to assure the fluid is at normal operating temperature.
- Raise and support the vehicle safely on jackstands. Remember that the vehicle must be supported level (usually at four points) so the proper amount of fluid can be added.
- Place a drain pan under the transmission housing, below the drain plug. Remember that the fluid will likely flow with some force at first (arcing outward from the transmission), and will not just drip straight downward into the pan. Position the drain pan accordingly and move it more directly underneath the drain plug as the flow slows to a trickle.
- Remove the drain plug and allow the transmission fluid to drain out.
The transmission drain plug is usually a square receiver which is designed to accept a3/8in. driver such as a ratchet or extension.
- Once the transmission has drained sufficiently, install the the drain plug.
- Remove the filler plug, and fill the transmission to the proper level with the required fluid.
- Reinstall the filler plug once you are finished.
- Remove the jackstands and carefully lower the vehicle.