Table 2-2. Troubleshooting

TM 10-3930-242-34

MALFUNCTION

TEST OR INSPECTION

TEST INSPECTION

CORRECTIVE ACTION

Step 8. Check for dirty lubrication pressure valve,

Step 3. Check for scored piston rod.

sticking open.

Replace defective piston rod (para 5-15).

If sticking, clean valve (para 4-4).

17.

HYDRAULIC SYSTEM LOSES PRESSURE.

23. CONVERTER STALL SPEED LOW.

Step 1. Check for defective hydraulic control valve.

Step 1. Check for improperly adjusted throttle link-

Repair or replace defective hydraulic con-

age.

trol valve (para 6-2, 6-3, 64, or 6-8).

If improperly adjusted, adjust throttle

Step 2. Check for defective hydraulic pump.

linkage for full governor travel (para 3-7).

Repair or replace defective hydraulic

Step 2. Check for improperly tuned engine.

pump (para 6-15 or 6-16).

If improperly tuned, tune engine (para

18.

HYDRAULIC VALVES WILL NOT HOLD.

3-7,3-14, and 3-15).

Step 1. Check for scored valve spool.

24. CONVERTOR STALL SPEED HIGH.

Rep] ace defective valve spool (para 6-2 or

Step 1. Check for low convertor pressure.

6-4).

If pressure is low, overhaul transmission

Step 2. Check for dirt or foreign matter in valve.

(para 4-2).

Clean valve (para 6-2 or 64).

Step 2. Check for slipping clutches.

Step 3. Check for weak or broken detent spring.

If clutches are slipping, rebuild transmis-

Replace defective spring (para 6-2).

sion (para 4-2),

19.

TRUCK LOSES FOUR WHEEL DRIVE.

Step 3. Check for freewheeling stator.

Step 1. Check for defective or wrongly adjusted

If stator freewheeling, rebuild transmis-

transmission control cable.

sion (para 4-2).

Adjust or replace cable (para 4-2i).

25. TRANSMISSION OIL TEMPERATURE HIGH.

Step 2. Check for defective shifter coupling.

Step 1. Check for low oil level.

Replace defective shifter coupling (para

If low, add oil to proper level. Refer to the

5-7).

lubrication order.

Step 3. Check for defective planetary gears (find

Step 2. Check for high oil level.

drive).

If oil level high, drain oil to proper level.

Replace defective planetary gears (para

Step 3. Check for low water level in engine cooling

4-2).

system.

20.

DIFFERENTIALS EXCESSIVELY NOISY.

Allow engine and transmission to cool.

Step 1. Check for broken or worn bearing.

Add coolant and check for leaks. Correct as

Replace defective bearing (para 5-6).

required.

Step 2. Check for defective pinion and ring gear.

Step 4. Check for extended operation in inefficient

Replace defective ring and pinion gear

transmission range.

(para 5-6)

Operate unit in lower transmission range.

21.

PLANETARY DRIVES EXCESSIVELY NOISY.

26. FORKLIFT TRUCK HAS POWER LOSS.

Step 1. Check for worn or broken planetary gear.

Step 1. Check for low engine output.

Replace defective planetary gears (para

Check engine tune, If necessary, tune en-

4-2).

gine (para 3-7, 3-14, and 3-15).

Step 2. Check for worn or broken bearings.

Step 2. Check for slipping clutch,

Replace defective bearings (para 4-2).

Check clutch pressure (para 4-2h).

22.

TRANSMISSION MAIN PRESSURE LOW.

Step 3. Check for low main pressure.

Step 1. Check for low oil level.

Refer to 22, above.

Add oil if low. Refer to the lubrication

Step 4. Check for improper convertor functioning

order,

such as stator (or stators) locked, convertor

Step 2. Check for clogged strainer screen.

element interference, or noise at stall.

Clean strainer screen (para 4-2).

Overhaul torque converter (para 4-2).

Step 3. Check for defective main pressure regulator

27. NO POWER TRANSMITTED IN ANY RANGE.

spring.

Step 1. Check for proper positioning of control val-

Replace defective spring (para 4-4).

ves.

Step 4. Check for main pressure regulator valve

Adjust control valve linkage if necessary

sticking open,

(para 4-2).

Rebuild main pressure regulator body as-

Step 2. Check for low main pressure.

sembly (para 4-4).

Refer to 22, above.

Step 5. Check for clutch cutoff valve sticking open.

Step 3. Check for mechanical failure.

Rebuild control valve body assembly (para

Disassemble and rebuild the transmission

4-5).

(para 4-2).

Step 6. Check for aerated oil (foaming).

28. NO POWER TRANSMITTED IN ONE RANGE.

Oil level high, or of improper grade. If

Step 1. Check for slipping clutch by checking clutch

high, drain to proper level. If improper

grade, drain and fill. Refer to the lubrica-

pressure (para 4-2h) and by checking for

worn piston seals.

tion order.

Rebuild transmission if necessary (para

Step 7. Check for worn or damaged input oil pump.

4-2).

If damaged, rebuild pump (para 4-2).

2-3