Torque Converter

Remove and replace the torque converter on a 1972 Ford F-100 with 302ci V8 and automatic transmission, requiring transmission removal to access the converter.

Warnings

Tools required

Parts

• Torque converter × 1 — Use OEM specification for C4 or C6 transmission
• Transmission pan gasket × 1 — Use OEM specification
• Transmission filter × 1 — Use OEM specification
• Flexplate-to-converter bolts × 4 — 7/16"-20 thread, replace if damaged
• Driveshaft U-joint straps or bolts × 1 — Replace if worn
• Transmission crossmember bolts × 4 — Replace if corroded

Fluids

• Type F ATF — 11 qt

Preparation

1. Park vehicle on level, solid surface and apply parking brake firmly
2. Place wheel chocks behind rear wheels
3. Disconnect negative battery cable
4. Raise vehicle and support securely on jack stands at frame rails
5. Allow exhaust system to cool completely if vehicle was recently driven
6. Mark driveshaft and rear axle yoke alignment with paint for reinstallation reference
7. Position transmission jack nearby and verify operation

Procedure

1. 1

   Drain transmission fluid
   Position a large drain pan under the transmission pan. Remove the transmission pan bolts starting from one corner and working around, leaving 2 bolts partially threaded at one corner to control fluid drainage. Once most fluid has drained, remove remaining bolts and lower the pan. Remove the transmission filter by pulling straight down. Expect approximately 5-6 quarts to drain from the pan.
2. 2

   Disconnect driveshaft
   Remove the 4 U-joint strap bolts or U-bolts connecting the driveshaft to the rear axle pinion yoke. Support the driveshaft and slide it rearward to disengage the slip yoke from the transmission output shaft. Lower the driveshaft and set aside. Plug the transmission extension housing with a rag or rubber plug to prevent fluid loss and contamination.
3. 3

   Disconnect transmission linkage and cooler lines
   Disconnect the shift linkage at the transmission lever by removing the clevis pin or linkage clip. Disconnect the kickdown linkage if equipped. Using a flare nut wrench, disconnect both transmission cooler lines at the transmission fittings. Cap or plug the lines and transmission ports immediately to prevent contamination. Position lines out of the way.
4. 4

   Disconnect speedometer cable and electrical connections
   Unscrew the speedometer cable from the transmission extension housing. Disconnect any electrical connectors including the neutral safety switch and backup light switch connections. Note that a 1972 C4/C6 is hydraulically controlled and has no shift solenoids. Label connections if necessary for reinstallation reference.
5. 5

   Support engine and remove transmission crossmember
   Position a floor jack with a wood block under the engine oil pan to support engine weight. Remove the 2 bolts securing the transmission mount to the crossmember. Remove the 4 bolts securing the crossmember to the frame rails. Lower and remove the crossmember.
6. 6

   Remove transmission access cover and mark converter position
   Remove the flexplate inspection cover from the bottom of the bellhousing. This cover is secured by 2-3 bolts. With the cover removed, you will have access to the flexplate and torque converter. Using marking paint, mark the relationship between the torque converter and flexplate for balanced reassembly.
7. 7

   Remove flexplate-to-converter bolts
   Using a breaker bar on the crankshaft pulley bolt, rotate the engine to access each of the 4 flexplate-to-converter bolts through the inspection opening. Block the flexplate with a pry bar or wedge to prevent rotation while removing each bolt. Remove all 4 bolts and retain them for inspection. Rotate the converter to verify all bolts are removed.
8. 8

   Remove transmission-to-bellhousing bolts
   Remove the upper and lower bellhousing-to-transmission bolts. There are typically 4-6 bolts securing the transmission to the engine bellhousing. Access the upper bolts from above the transmission. Ensure all bolts are removed before attempting to separate the transmission.
9. 9

   Remove transmission assembly
   Position the transmission jack securely under the transmission pan with the adapter centered. Secure the transmission to the jack with a safety chain or strap. Carefully slide the transmission rearward, keeping it level, until the input shaft clears the bellhousing. Watch that the torque converter remains fully seated in the transmission pump during removal. Once clear, lower the transmission jack and remove the transmission from under the vehicle. Have an assistant guide the transmission to prevent binding.
10. 10

    Secure and remove torque converter
    With the transmission on a bench or stand, install a C-clamp or converter retention tool across the bellhousing to prevent the converter from sliding out. Carefully tilt the transmission to drain remaining fluid from the converter into a drain pan. Remove the retention tool and slide the torque converter straight out of the transmission pump. The converter should slide out with moderate effort; if resistance is felt, verify the converter hub is aligned and not binding in the pump.
11. 11

    Inspect flexplate and pump components
    Inspect the engine flexplate for cracks, particularly around the mounting bolt holes and center hub. Check for signs of impact or heat discoloration. Inspect the crankshaft pilot bearing or bushing in the crankshaft for wear. Inspect the transmission pump seal and bushing for wear or damage. Replace any damaged components before installing the new converter.
12. 12

    Install new torque converter
    Pour approximately 1 quart of fresh Type F ATF into the new torque converter. Carefully align the converter hub with the transmission pump and slide the converter into the pump bore. Rotate the converter while pushing it in to engage the pump drive gear, then the turbine shaft splines, and finally the stator support splines. The converter should seat in three distinct stages with approximately 1/2 inch of movement at each stage. Verify the converter is fully seated by confirming it has engaged all three stages and that the converter pilot/mounting pad sits recessed behind the bellhousing face rather than flush or proud. Consult the transmission service manual for the exact seat-depth dimension before proceeding. Install the retention tool to prevent the converter from sliding out during installation.
13. 13

    Install transmission assembly
    Position the transmission on the transmission jack and raise it into position under the vehicle. Carefully align the input shaft with the bellhousing bore and slide the transmission forward, keeping it level. Do not allow the transmission weight to hang on the input shaft. Verify the converter remains fully seated. Once the transmission is flush with the bellhousing, install the bellhousing-to-transmission bolts and tighten to 40-50 ft-lbs in a cross pattern.
14. 14

    Install flexplate-to-converter bolts
    Remove the converter retention tool. Rotate the crankshaft to align the first flexplate bolt hole with a converter mounting hole. Start all 4 flexplate-to-converter bolts by hand, aligning the marks made during disassembly. Using the crankshaft pulley bolt to rotate the engine, tighten each bolt to 28-40 ft-lbs in a cross pattern. Verify all 4 bolts are fully seated and torqued. Verified detail (Torque specification for flexplate-to-converter bolts on 1972 Ford F-100 302ci V8): 63.0 lb-ft (85.0 Nm)
15. 15

    Reinstall crossmember and remaining components
    Raise the transmission jack slightly to position the transmission mount to the crossmember. Install the crossmember to the frame rails and tighten the 4 mounting bolts to 70.0 lb-ft (95.0 Nm). Install the 2 transmission mount-to-crossmember bolts and tighten to 30-40 ft-lbs. Remove the floor jack from under the engine. Install the flexplate inspection cover with its 2-3 bolts.
16. 16

    Reconnect driveshaft and linkages
    Remove the plug from the transmission extension housing. Lubricate the slip yoke with ATF and slide it into the extension housing, aligning the splines. Connect the driveshaft to the rear axle yoke, aligning the marks made during disassembly. Install the 4 U-joint strap bolts or U-bolts and tighten to 26.0 lb-ft (35.0 Nm). Reconnect the shift linkage and kickdown linkage. Verify smooth movement of all linkages.
17. 17

    Reconnect cooler lines and electrical connections
    Remove the caps from the transmission cooler lines and transmission ports. Connect both cooler lines using flare nut wrenches and tighten fittings to 10-15 ft-lbs. Do not overtighten. Reconnect the speedometer cable and all electrical connectors. Verify all connections are secure.
18. 18

    Install new filter and transmission pan
    Install the new transmission filter by pushing it onto the pickup tube until fully seated. Clean the transmission pan and mating surface on the transmission case thoroughly. Install the new pan gasket and position the pan. Install all pan bolts and tighten in a cross pattern to 10-12 ft-lbs. Do not overtighten as this can distort the pan and cause leaks. Verified detail (Torque specification for transmission pan bolts on 1972 Ford F-100 C4/C6 transmission): 9.0 lb-ft (12.0 Nm)
19. 19

    Fill transmission with fluid
    Lower the vehicle to the ground. Add 5 quarts of Type F ATF through the dipstick tube. Start the engine and allow it to idle. With the parking brake applied and your foot on the brake pedal, shift through all gear positions, pausing 2-3 seconds in each position. Return to Park. Check the fluid level on the dipstick with the engine running and fluid at operating temperature. Add fluid as necessary to bring the level to the FULL mark. Total capacity is approximately 9-10 quarts for the C4 or approximately 12-13 quarts for the C6, including the torque converter. Verify the exact capacity for your transmission and fill to the dipstick FULL mark rather than by volume alone.

Reassembly

1. Torque all fasteners to specifications during reassembly
2. Verify torque converter is fully seated before installing transmission; improper seating will prevent proper bolt-up and cause immediate failure
3. Always replace transmission filter and pan gasket during torque converter service
4. Align driveshaft marks to maintain balance and prevent vibration

Verification

• Start engine and verify no transmission fluid leaks at pan, cooler lines, or extension housing
• With engine at idle and transmission in Park, verify smooth engagement when shifting to Drive and Reverse
• Verify proper transmission fluid level at operating temperature with engine running
• Test drive vehicle and verify smooth shifts through all gears with no slipping, shuddering, or unusual noises
• Recheck fluid level after test drive and top off if necessary
• Inspect for leaks after test drive, particularly at pan gasket and cooler line connections

More procedures for this vehicle