System Pressure And Stall Speed, Check

System pressure and stall speed check

Special tools:
999 2531 MANOMETER 999 2531 Manometer
999 5074 NIPPLE 999 5074 NIPPLE

Oil level check
See Checking oil level Checking Oil Level.

Manometer connection




Loosen the air filter.
Remove the test plug from the transmission. Install nipple 999 5074 NIPPLE 999 5074 NIPPLE.
Connect the hose and manometer 999 2531 MANOMETER 999 2531 Manometer to the nipple.

Idle speed check
Start the engine and allow it to idle with the selector lever in position N.
Check idle speed. See the table below.

System pressure check
Depress the brake pedal.
Move the selective levers to the various gears and read off system pressure.





1), 800 rpm, model year 1992-1993

Check stall speed in conjunction with a system pressure check.
The check primarily provides information on the condition of the torque converter, transmission clutches and the engine.
The following is necessary to ensure correct test results:
- The engine provides full output
- System pressure is correct
- the transmission has the correct oil level and operating temperature

Note! Never check stall speed if system pressure is low

Check
Connect a tachometer so that it can be read from the driver's seat.
Air conditioning (AC) should be off. Place chocks behind all four wheels. Start the engine.

Caution! Apply the handbrake and depress the brake pedal hard with your left foot during the check.

Move the gear selector lever to position D . Apply full throttle for max 5 seconds and read off the highest rpm as well as system pressure. Compare with the table below.

Note! The stall speed check must not last more than 5 seconds.





1)See specifications.
Repeat the check with the gear selector in R.
Compare with the table.
If the rpm exceeds the table values, see High stall speed ; if speed is below the table values, see Low stall speed .

High stall speed
The conditions of element above are fulfilled. Is the acceleration time for 0-100 km/h normal?
If the actual stall speed exceeds the normal value by more than 300 rpm:
- Check if the oil is discolored or has a foul odor. See Oil, quality check Oil, Quality Check.
If the oil is OK, replace the torque converter: (See for the procedure for torque converter replacement.).
- For gasoline engines, see Gearbox/torque converter, replacing Gearbox/Torque Converter, Replacing.
Dirty oil indicates worn or burnt clutch discs; replace the transmission.
- For gasoline engines, see Gearbox/torque converter, replacing Gearbox/Torque Converter, Replacing.
Recheck stall speed after transmission replacement.

Low stall speed
Conditions of work element above are fulfilled.
If the actual stall speed falls below the normal value by more than 300 rpm:
Try with a new torque converter. (See Gearbox/torque converter, replacing Gearbox/Torque Converter, Replacing for gasoline engines and for diesel engines for the procedures that also apply to replacement of torque converter.)
Recheck stall speed after torque converter replacement. If the problem remains, replace the transmission:
- For gasoline engines, see Gearbox/torque converter, replacing Gearbox/Torque Converter, Replacing.
Noise:
Replace the transmission:
- For gasoline engines, see Gearbox/torque converter, replacing Gearbox/Torque Converter, Replacing.
Recheck stall speed after transmission replacement.