Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
1987 Ford Bronco II 4WD V6-177 2.9LFACTORY OEM SERVICE PROCEDURE
A/T - Torque Converter Slip/DTC 628/P0741 Set
Article No.
97-22-4
10/27/97
TRANSMISSION - A4LD, 4R44E/4R55E, 5R55E - TORQUE CONVERTER SLIP - DIAGNOSTIC TROUBLE CODE (DTC) 628 OR P0741 STORED IN MEMORY
FORD:
1985-93 MUSTANG
1987-88 THUNDERBIRD
LINCOLN-MERCURY:
1988 COUGAR
LIGHT TRUCK:
1985-90 BRONCO II
1985-97 RANGER
1987-97 AEROSTAR
1991-97 EXPLORER
ISSUE:
Some vehicles may experience excessive torque converter slippage, torque converter not engaging, or Diagnostic Trouble Code (DTC) 628 or P0741 stored in memory. This may be caused by damage to the fluid pump support seal and/or to the groove on the pump where the seal is located.
ACTION:
Inspect the fluid pump seal for damage. Refer to the following Service Procedure for details.
SERVICE PROCEDURE
1. Follow normal diagnostic procedures as listed in the appropriate Service Manual.
2. Inspect the fluid pump support for damage. If damaged, also inspect the fluid pump support seal groove on the pump.
3. If the groove is damaged, replace the pump.

4. If the groove is not damaged, replace the fluid pump support seal with a redesigned Seal (F77Z-7L323-AA). Refer to Figure 1.
5. Do not replace the torque converter unless it is damaged or fails the criteria listed in the appropriate Service Manual and/or refer to TSB 96-26-12.
PART NUMBER PART NAME
F77Z-7L323-AA Fluid Pump Support Seal
OTHER APPLICABLE ARTICLES: 96-26-12
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES: 501000, 502000, 504000
97-22-4
10/27/97
TRANSMISSION - A4LD, 4R44E/4R55E, 5R55E - TORQUE CONVERTER SLIP - DIAGNOSTIC TROUBLE CODE (DTC) 628 OR P0741 STORED IN MEMORY
FORD:
1985-93 MUSTANG
1987-88 THUNDERBIRD
LINCOLN-MERCURY:
1988 COUGAR
LIGHT TRUCK:
1985-90 BRONCO II
1985-97 RANGER
1987-97 AEROSTAR
1991-97 EXPLORER
ISSUE:
Some vehicles may experience excessive torque converter slippage, torque converter not engaging, or Diagnostic Trouble Code (DTC) 628 or P0741 stored in memory. This may be caused by damage to the fluid pump support seal and/or to the groove on the pump where the seal is located.
ACTION:
Inspect the fluid pump seal for damage. Refer to the following Service Procedure for details.
SERVICE PROCEDURE
1. Follow normal diagnostic procedures as listed in the appropriate Service Manual.
2. Inspect the fluid pump support for damage. If damaged, also inspect the fluid pump support seal groove on the pump.
3. If the groove is damaged, replace the pump.
4. If the groove is not damaged, replace the fluid pump support seal with a redesigned Seal (F77Z-7L323-AA). Refer to Figure 1.
5. Do not replace the torque converter unless it is damaged or fails the criteria listed in the appropriate Service Manual and/or refer to TSB 96-26-12.
PART NUMBER PART NAME
F77Z-7L323-AA Fluid Pump Support Seal
OTHER APPLICABLE ARTICLES: 96-26-12
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES: 501000, 502000, 504000
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- β’ You smell fuel, burning insulation, or see smoke.
- β’ Brakes feel soft, pull hard to one side, or make grinding noises.
- β’ The engine overheats, stalls repeatedly, or misfires under load.
- β’ You are missing required tools, torque specs, or safe lifting equipment.
- β’ You are not confident in the next step or safety outcome.
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