Specifications

Power Train Testing and Adjusting 40
7. Low oil flow through converter. Converter relief
valve stuck open (converter bypass orifice plugged)
8. Incorrect use of vehicle. Loads are too heavy for the
lift truck.
9. Too much inching operation (slipping the clutch
plates and discs).
10. Too much stalling of torque converter.
11.Cooler relief valve stuck open, full oil flow does
not go through oil cooler.
Problem: Clutch engagement is slow or loss of
power during engagement.
Probable cause:
1. Low oil pressure
2. Air mixed in the oil.
a. Air leaks on suction side of pump.
b. Low oil level also causes aeration.
3. Inching valve linkage adjustment is not correct.
4. Modulating valve assembly leaks or partially stuck.
Problem: Clutch engagement makes a rough shift.
Probable cause:
1. Modulating valve assembly, load piston and/or
reducing valve stuck.
Problem: Vehicle operates in one direction and
creeps in that direction in NEUTRAL. Engine stalls
when shifted to the other direction
.
Probable cause:
1. Failure of clutch in the direction the lift truck moves.
Clutch discs or plates are warped (damaged) or
held together because of too much heat.
2. Failure of the modulating valve assembly in the
direction the lift truck moves. The valve assembly
stuck in the engaged position possibly caused by
metal burrs (particles) or oil contamination.
Check List from Operation Noise
Problem: Noise in NEUTRAL only.
Probable cause:
1. Worn one-way clutch in torque converter.
2. Low oil level (pump cavitation).
3. Worn bearing next to pump.
Problem: Pump noise not normal
Probable cause:
1. A loud sound at short time periods gives an
indication that foreign material is in the
transmission hydraulic system.
2. A constant loud noise is an indication of pump
failure.
Problem: Noise in the Transmission that is not
normal.
Probable cause:
1. Transmission components have wear or damage.
a. Damaged gears.
b. Worn teeth or clutch plates and/or clutch discs.
c. Slipping clutch plates and disc noise.
d. Other component parts have wear or damage.
e. Failure of the thrust washers.
2. Modulating valve assembly makes noise.
Problem: Constant noise in the Drive axle.
Probable cause:
1. Lubricant not to the specific level.
2. Wrong type of lubricant.
3. Wheel bearings out of adjustment or have a defect.
4. Bevel gears not in adjustment for correct tooth
contact.
5. Teeth of bevel gear have damage or wear.