Hummer H1 Service Manual page 244

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Problem
6. Overdrive roller clutch failure.
7. Valve body fault:
Engine Stalls
1. Idle speed incorrect (too low).
When Trans-
2. Torque converter clutch stuck in applied posi-
mission Is
Shifted Into
Gear
3.
4.
Slips In Drive/ 1. Low fluid level.
Reverse
2. Low fluid pressure.
3. Reverse servo seal failure (reverse range only).
No First Gear 1. Low roller clutch failure (not attached or bro-
In Either D
Range
2. Center support race, splines, or snap ring fail-
3. Forward clutch problem.
4. Overdrive roller clutch problem.
5. Shift solenoid fault (either solenoid).
No First Gear in 1. Low roller clutch failure.
1 Range (Man-
2. Center support fault:
ual Low)
3. Forward clutch fault.
4. Overdrive roller clutch failure.
5. Rear band fault:
6. Shift solenoid fault.
No Second 1. Overdrive roller or intermediate sprag clutch
Gear
2. Center support problem:
05745159
TRANSMISSION DIAGNOSIS GUIDE (Cont'd)
Potential Cause
• manual valve stuck, damaged
• Pressure switch failure
tion, or clutch is dragging.
Forward clutch seized.
Fourth clutch seized or dragging.
ken).
ure.
• race broken
• splines damaged
• snap ring not seated
• case damaged
• band worn
• servo failure
• incorrect apply pin
damage.
• snap ring not seated
• splines or race damaged
• support bolt missing, damaged
Transmission/Transfer Case
Correction
6. Replace transmission.
7. Remove and free-up binding valves. Replace
switch assembly if failed. Replace trans-
mission if valve body bores are damaged.
1. Check PCM operation with scan tool on turbo
diesel.
2. Check converter clutch valve and solenoid
operation. If OK, replace converter.
3. Replace transmission.
4. Replace transmission.
1. Top off fluid level and check for leaks.
2. Check line pressure and overhaul pump if low.
3. Overhaul servo.
1. Replace transmission.
2. Replace transmission.
3. Replace transmission.
4. Replace transmission.
5. Check with scan tool and replace as needed.
1. Replace transmission.
2. Replace transmission.
3. Replace transmission.
4. Replace transmission.
5. Replace transmission.
6. Check A and B solenoids with scan tool and
repair as needed.
1. Replace transmission.
2. Replace transmission.
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