Automatic Transmission - Cvt: Maintenance Mercury Montego III

Internal Fluid Filter

The high pressure transmission fluid filter is located inside of the transaxle housing, just behind the transmission pressure filter case cover. The transmission filter is accessible by removing the transmission pressure filter case cover. The filter should be changed ever time the fluid is changed or whenever the transaxle is overhauled.

Fluid Pump

The fluid pump is a high-pressure radial-piston pump, the pump flow is controlled by the main pressure regulator in the valve body portion of the mechatronic unit. There are 8 pistons located radially around the circumference of the pump.

The pump is driven directly from the engine via the outer housing of the converter and supplies the transaxle with fluid. The converter is not supported on the pump bearings but on a plain bearing between the stator shaft and the converter hub. The pump draws in fluid from the fluid pan filter and discharges fluid at high pressure to the main regulator valve in the valve body.

Transmission Fluid Temperature (TFT) Sensor

The TCM utilizes one transmission fluid temperature sensor which is integrated within the TCM. The TCM uses the sensor input to activate various operational strategies.

High Fluid Level

A fluid level that is too high may cause the fluid to become aerated due to the churning action of the rotating internal parts. This will cause foaming, loss of fluid from the vent tube, fluid level indicator tube and possible transaxle malfunction and/or damage. If an overfill reading is indicated, loosen the fluid drain plug and allow a small amount of fluid to drain and re-check fluid level.

Low Fluid Level

A low fluid level could result in poor transaxle engagement, slipping of the chain, malfunction and damage to the transaxle variators. This could also indicate a leak in one of the transaxle seals or gaskets. Under normal circumstances, the fluid level should be checked during normal maintenance. If the transaxle starts to slip or shows signs of fluid leaking, the fluid level and DTCs should be checked.

Adding Fluid

If fluid needs to be added, add fluid in 0.25L (1/2 pint) increments through the fluid fill plug located on the top of the transaxle near the fluid level indicator. Do not overfill the fluid. For fluid type, refer to the SPECIFICATION CHART .

Fluid Condition Check

Note. The continuously variable transaxle (CVT) fluid is bluish-green when it is new. The CVT fluid will darken from bluish-green to darker green or brown as it ages. If there is an internal concern with a mechanical component, there will be metallic residue in the pan. With other transmission fluids, the odor was an indicator of heat damage or other concerns. With CVT fluid, the odor will not indicate heat damage or other concerns.

1. Check the fluid level.
2. Observe the color. The color under normal circumstances should be bluish green when new and will darken to dark green or brown as it ages, not black.
3. Hold the fluid level indicator over a white facial tissue and allow the fluid to drip onto the facial tissue and examine the stain.
4. If evidence of solid material is found, the transmission fluid pan should be removed for further inspection.
5. If fluid contamination or transaxle failure is confirmed by the sediment in the bottom of the fluid pan, the transaxle must be disassembled and completely cleaned or installed new.
6. If the transaxle is to be overhauled or if installing a new transaxle, install a new transmission fluid cooler and clean and flush the fluid cooler tubes. Refer to «TRANSAXLE/TRANSMISSION COOLING»(ref-233053) .
7. Carry out diagnostic checks and adjustments. Refer to «DIAGNOSIS BY SYMPTOM»(ref-233028-S04141298392006052400000) .

Drain

Note. Install a new high-pressure case filter when changing the transmission fluid. For additional information, refer to HIGH PRESSURE FILTER AND CASE COVER .

Scheme 291

1. With the vehicle in NEUTRAL, position it on a hoist. For additional information, refer to «JACKING & LIFTING»(ref-232992) .
2. Remove the fluid pan drain plug and allow the fluid to drain.
3. Install the fluid pan drain plug. Tighten to 25 Nm (18 lb-ft).
4. Fill the transaxle with approximately 4.7 L (5 quarts) of clean CVT automatic transmission fluid. Use the transmission fluid level setting procedure to fill the transaxle. For additional information, refer to «TRANSMISSION FLUID LEVEL CHECK AND SETTING»(ref-233028-S31912964632006052400000) .