General Motors recommends the use of DEXRON®-III automatic transmission fluid.
3T40 Automatic Transaxle
See Figures 1, 2, 3 and 4
The transmission dipstick is located to the left (if facing the engine) of the brake master cylinder. The dipstick handle is usually RED .
- Park the vehicle on a level surface.
- The transaxle should be at normal operating temperature when checking fluid level. To ensure the fluid is at normal operating temperature, drive the vehicle at least 10 miles.
- With the selector lever in P and the parking brake applied, start the engine.
- Open the hood and locate the transaxle fluid dipstick. Pull the dipstick from its tube, wipe it clean, and reinsert it. Make sure the dipstick is fully inserted.
- Pull the dipstick from its tube again. Holding it horizontally, read the fluid level. The fluid should be between the MIN and MAX mark. If the fluid is below the MIN mark, add fluid through the dipstick tube.
- Insert the dipstick, and check the level again after adding any fluid. Be careful not to overfill the transaxle.
See Figure 5
The fluid level screw is intended to be used for diagnosing a transaxle fluid leak or resetting the transaxle fluid level after service that involves a lose of fluid.
- The fluid level should be checked when the transaxle is near room temperature or at 104°F (40°C). To acquire this, left the car idle for 3-5 minutes with all of the accessories off.
- Apply the brake, then move the gear shift selector through all gear ranges, pausing three seconds in each range. Shift the lever into P .
- Raise and safely support the vehicle.
- Place a suitable drain pan under the check plug to catch any fluid that may drip out.
- Remove the oil check plug. The oil level should be at the bottom of the oil check hole. Because the transaxle operates correctly over a range of fluid levels, fluid may or may not drain out of the screw hole when the screw is removed.
- If fluid drains through the screw hole, the transaxle may have been overfilled. When fluid stops draining, then fluid level is correct and the check plug may be installed. If fluid does not drain through the screw hole, the transaxle fluid may have been low. Add fluid at the vent cap location in 1 pint increments until the oil level is at the bottom of the oil check hole.
- Install the oil check plug/fluid level screw and tighten to 10 ft. lbs. (14 Nm).
- Carefully lower the vehicle.
PAN & FILTER SERVICE
See Figures 6 through 17
The fluid should be changed according to the schedule in the Maintenance Intervals chart. If the car is normally used in severe service, such as stop and start driving, trailer towing, or the like, the interval should be halved. If the car is driven under especially nasty conditions, such as in heavy city traffic where the temperature normally reaches 90°F (32°C), or in very hilly or mountainous areas, or in police, taxi, or delivery service, the fluid should be changed every 15,000 miles (24,000 km.).
The fluid must be hot before it is drained; a 20 minute drive should accomplish this.
- To drain the automatic transaxle fluid, the fluid pan must be removed. Raise and safely support the vehicle. Place a drain pan underneath the transaxle pan, then remove the pan attaching bolts except on the four corners of the pan.
- Loosen the four attaching bolts on the corners approximately four turns each, but do not remove them.
- Very carefully pry the pan loose on one corner. You can use a small prybar for this if you work CAREFULLY. Do not distort the pan flange, or score the mating surface of the transaxle case. You'll be very sorry later if you do. As the pan is pried loose, all of the fluid is going to come pouring out.
- Carefully break the other corners loose until fluid is flowing steadily from the entire pan.
- After the fluid is down flowing, remove one corner bolt and attempt to drain any remaining fluid. Remove the remaining bolts and remove the pan and gasket. Throw away the gasket.
- Clean the pan with solvent and allow it to air dry. If you use a rag to wipe out the pan, you risk leaving bite of lint behind, which will clog the dinky hydraulic passages in the transaxle.
- Remove and discard the filter and the O-ring seal.
- Install a new filter and O-ring, locating the filter against the dipstick stop.
- Position a new gasket on the pan, then install the pan. Tighten the bolts evenly and in rotation to 8 ft. lbs. (11 Nm.). Do not overtighten.
- Add approximately 4 qts. (3.8 L) of DEXRON®III or IIE automatic transmission fluid to the transaxle through the dipstick tube. You will need a long necked funnel, or a funnel and tube to do this.
- With the transaxle in P , put on the parking brake, block the front wheels, start the engine and let it idle. DO NOT RACE THE ENGINE. DO NOT MOVE THE LEVER THROUGH ITS RANGES.
- With the lever in Park, check the fluid level. If it's OK, take the car out for a short drive, park on a level surface, and check the level again, as outlined earlier in this section. Add more fluid if necessary. Be careful not to overfill, which will cause foaming and fluid loss.
If the drained fluid is discolored (brown or black), thick, or smells burnt, serious transmission troubles, probably due to overheating, should be suspected. Your car's transaxle should be inspected by a reliable transmission specialist to determine the problem.