Powertrain
Low/Reverse clutch assembly. Diagnosis and Testing
In this manual: Powertrain
~9min read
Low/Reverse Clutch
For Low/Reverse clutch operation,
REFER TO: Transmission Description - System Operation and Component Description (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Description and Operation).
REFER TO: Low/Reverse Clutch Assembly (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Description and Operation).
Low/Reverse Clutch
| Condition | Possible Sources | Action |
| Low/Reverse clutch not applied | SSD filter screen blocked | CLEAN or INSTALL a new solenoid. REFER TO: Solenoid (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Removal and Installation). |
| SSD mechanically stuck in the OFF position | INSTALL a new solenoid. REFER TO: Solenoid (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Removal and Installation). | |
| Low/Reverse, 4-5-6 clutch regulator valve stuck in closed position | DISASSEMBLE, CLEAN and INSPECT the low/reverse clutch regulator valve. If the bore or valve is damaged, INSTALL a new main control valve body. REFER TO: Main Control Valve Body (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). |
|
| VBS CBR1/456, CBR1/456, CBR1 hydraulic circuits blocked or leaking. | DISASSEMBLE and INSPECT the main control valve body and separator plate passages for debris/blockage. CLEAN as necessary. REFER TO: Main Control Valve Body (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). | |
| Clutch bypass valve stuck in home position | DISASSEMBLE, CLEAN and INSPECT the multiplex shift valve. If the bore or valve is damaged, INSTALL a new main control valve body. Refer to Main Control Valve Body (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). | |
| Low and Reverse Clutch Apply Seal to Transmission Case | REMOVE the main control valve body. Refer to Main Control Valve Body (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Removal and Installation). INSPECT the CBR1 circuit seal between the main control valve body and the transmission case for absence or damage. INSTALL a new seal. |
|
| Rear Planetary Carrier/Sun Gear | INSPECT the planetary carrier/sun gear for wear and damage that would prevent the gear from holding. INSTALL new components as necessary. Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). |
|
| Low/Reverse Clutch Friction Plates | DISASSEMBLE and INSPECT the low/reverse clutch friction and steel plates. INSTALL new components as necessary. Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). |
|
| Low/Reverse Clutch Piston Seal Leak | INSPECT the low/reverse clutch piston and seal. INSTALL new components as necessary. Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). |
|
| Center support cracked or leaking. | INSPECT the center support for damage. INSTALL new components as necessary. Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). |
|
| Low/Reverse Clutch Always Applied | SSD O-Rings Damaged/Leaking | INSTALL a new solenoid. REFER TO: Solenoid (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Removal and Installation). |
| SSD mechanically stuck in the ON position | INSTALL a new solenoid. REFER TO: Solenoid (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Removal and Installation). | |
| Low Reverse/Overdrive (4, 5, 6) Clutch Regulator Valve Stuck On | DISASSEMBLE, CLEAN and INSPECT the low/reverse clutch regulator valve and spring. If the bore, valve or spring is damaged, INSTALL a new main control valve body. Refer to Main Control Valve Body (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). | |
| VBS CBR1/456, CBR1/456, CBR1 Hydraulic Circuit Leak | DISASSEMBLE and INSPECT the main control valve body passages and separator plate for leaks. CLEAN as necessary. Refer to Main Control Valve Body (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). | |
| Low One-Way Clutch (OWC) | INSPECT the low one-way clutch (OWC) for free rotation in the reverse direction. INSTALL new components as necessary. Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). |
|
| Low/Reverse Clutch Friction Plates | DISASSEMBLE and INSPECT the low/reverse clutch friction and steel plates. INSTALL new components as necessary. Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). |
|
| Low/Reverse Clutch Piston Return Spring | INSPECT the return spring for damage. INSTALL new components as necessary. Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). |
|
| Low/Reverse Clutch Delayed/Soft/Slipping Engagement | Incorrect shift strategy programmed in PCM | Remove the SSD and record the solenoid tape number. Refer to Solenoid (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Removal and Installation). Using the diagnostic tool, verify that the correct range number is stored in the PCM. If the range numbers do not match, replace the SSD with the correct range number. |
| SSD Filter Screen Partially Blocked or Restricted. | CLEAN or INSTALL a new solenoid. REFER TO: Solenoid (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Removal and Installation). | |
| SSD mechanically sticking | INSTALL a new solenoid. REFER TO: Solenoid (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Removal and Installation). | |
| Low Reverse/Overdrive (4, 5, 6) Clutch Regulator Valve Sticking | DISASSEMBLE, CLEAN and INSPECT the low/reverse clutch regulator valve. If the bore or valve is damaged, INSTALL a new main control valve body. REFER TO: Main Control Valve Body (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). |
|
| Low Reverse/Overdrive (4, 5, 6) Clutch Lock Valve Stuck On | DISASSEMBLE, CLEAN and INSPECT the low/reverse clutch lock valve. If the bore or valve is damaged, INSTALL a new main control valve body. Refer to Main Control Valve Body (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). | |
| VBS CBR1/456, CBR1/456, CBR1 Hydraulic Circuits Blocked or Leaking | DISASSEMBLE and INSPECT the main control valve body and separator plate passages for debris/blockage. CLEAN as necessary. REFER TO: Main Control Valve Body (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). | |
| Low and Reverse Clutch Apply Seal to Transmission Case | REMOVE the main control valve body. Refer to Main Control Valve Body (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Removal and Installation). INSPECT the CBR1 circuit seal between the main control valve body and the transmission case for absence or damage. INSTALL a new seal. |
|
| Low/Reverse Clutch Friction Plates | DISASSEMBLE and INSPECT the low/reverse clutch friction and steel plates. INSTALL new components as necessary. Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). |
|
| Low/Reverse Clutch Piston Seal Leak | INSPECT the low/reverse clutch piston and seal. INSTALL new components as necessary. Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). |
|
| Center support cracked or leaking. | INSPECT the center support for damage. INSTALL new components as necessary. Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). |
|
| Low/Reverse Clutch Engages Abruptly | Incorrect shift strategy programmed in PCM | Remove the SSD and record the solenoid tape number. Refer to Solenoid (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Removal and Installation). Using the diagnostic tool, verify that the correct range number is stored in the PCM. If the range numbers do not match, replace the SSD with the correct range number. |
| SSD mechanically sticking | INSTALL a new solenoid. REFER TO: Solenoid (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Removal and Installation). | |
| Low Reverse/Overdrive (4, 5, 6) Clutch Regulator Valve Sticking | DISASSEMBLE, CLEAN and INSPECT the low/reverse clutch regulator valve and spring. If the bore, valve or spring is damaged, INSTALL a new main control valve body. Refer to Main Control Valve Body (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). | |
| Low Reverse/Overdrive (4, 5, 6) Clutch Lock Valve Stuck in OFF Position | DISASSEMBLE, CLEAN and INSPECT the low/reverse feed orifice, the clutch lockout valve and spring. If the orifice, valve or spring is damaged, INSTALL a new main control valve body. REFER TO: Main Control Valve Body (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). | |
| VBS CBR1/456, CBR1/456, CBR1 Hydraulic Circuits Blocked or Leaking | DISASSEMBLE and INSPECT the main control valve body and separator plate passages for debris/blockage. CLEAN as necessary. REFER TO: Main Control Valve Body (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). | |
| Low/Reverse Clutch Friction Plates | DISASSEMBLE and INSPECT the low/reverse clutch friction and steel plates. INSTALL new components as necessary. Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). |
|
| Low/Reverse Clutch Piston Return Spring | INSPECT the return spring for correct installation and damage. INSTALL new components as necessary. REFER TO: Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). REFER TO: Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). |
|
| - | Center support cracked or leaking. | INSPECT the center support for damage. INSTALL new components as necessary. Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). Refer to Transmission (307-01A Automatic Transmission - 6-Speed Automatic Transmission - 6F35, Overhaul). |
Test yourself
A quick Ford Fusion quiz: every answer comes with an explanation and a link to the manual page.
Was this page helpful?