Flexplate

Remove and replace the flexplate on a 1992 Dodge Viper 8.0L V10 by separating the transmission from the engine, removing the torque converter bolts, and installing a new flexplate with proper torque sequence.

Warnings

Tools required

Parts

• Flexplate × 1 — Use OEM specification for 8.0L V10
• Flexplate bolts × 8 — Use OEM specification, typically supplied with flexplate
• Transmission pan gasket × 1 — Use OEM specification
• Transmission fluid filter × 1 — Use OEM specification
• Rear main seal (if damaged during inspection) × 1 — Use OEM specification

Fluids

• ATF+3 automatic transmission fluid — 8 qt

Preparation

1. Ensure the vehicle is on a level surface and the parking brake is engaged.
2. Disconnect the negative battery cable and secure it away from the battery terminal.
3. Raise the vehicle on a lift or support it securely on jack stands at all four corners.
4. Remove the rear wheels to provide access to the exhaust and driveline components.
5. Allow the engine and exhaust system to cool completely if the vehicle was recently operated.
6. Place a drain pan under the transmission pan to catch fluid during removal.
7. Have a second person available to assist with transmission removal and installation.

Procedure

1. 1

   Drain transmission fluid and remove transmission pan
   Place a drain pan under the transmission pan. Remove the transmission pan bolts and lower the pan carefully, allowing fluid to drain. Remove the transmission filter and gasket. Clean the mating surface on the transmission case thoroughly with brake cleaner and a wire brush.
2. 2

   Remove exhaust system components
   Disconnect the exhaust system at the manifold flanges. Remove the exhaust crossover pipe and support brackets. Lower the exhaust system or remove it completely to provide clearance for transmission removal. The Viper uses a side-exit exhaust that must be disconnected at multiple points for adequate clearance.
3. 3

   Remove driveshaft
   Mark the driveshaft and differential flange orientation with paint or a marker for proper reassembly alignment. Remove the 4 bolts securing the driveshaft to the rear differential flange. Slide the driveshaft rearward to disengage it from the transmission output shaft. Support the driveshaft and remove it from under the vehicle. Inspect the universal joints for wear or damage.
4. 4

   Disconnect transmission cooler lines and electrical connections
   Locate the transmission cooler lines at the right side of the transmission. Place a drain pan underneath and disconnect the cooler lines, allowing remaining fluid to drain. Cap or plug the lines to prevent contamination. Disconnect all electrical connectors from the transmission, including the neutral safety switch, speed sensor, and solenoid pack connectors. Label connectors if necessary for reassembly reference.
5. 5

   Disconnect shift linkage and remove transmission bellhousing access cover
   Disconnect the shift cable from the transmission shift lever. Remove the shift cable bracket mounting bolts if necessary. Locate the bellhousing inspection cover on the lower front of the transmission bellhousing. Remove the cover bolts and remove the inspection cover to access the torque converter and flexplate.
   Torque spec

   Cover Bolts16 Nm (12 lb-ft)
6. 6

   Mark and remove torque converter bolts
   Using the bellhousing access opening, mark the relationship between the torque converter and flexplate with paint for reassembly balance reference. Rotate the crankshaft using a breaker bar on the crankshaft pulley bolt to access each torque converter bolt through the access opening. The torque converter has 4 bolts securing it to the flexplate. Remove all 4 torque converter bolts and push the torque converter back slightly into the transmission bellhousing to disengage it from the flexplate.
7. 7

   Support transmission and remove crossmember
   Position a transmission jack under the transmission oil pan with a block of wood to distribute the load. Raise the jack until it just contacts the transmission and secure the transmission to the jack with a safety chain or strap. Remove the transmission mount-to-crossmember mounting bolts. Remove the crossmember-to-frame mounting bolts and lower the crossmember from the vehicle.
   Torque spec

   Mounting Bolts47 Nm (35 lb-ft)
8. 8

   Remove transmission-to-engine mounting bolts
   Support the rear of the engine with an engine support fixture or hoist to prevent the engine from tilting when the transmission is removed. Remove all transmission-to-engine bellhousing bolts. There are typically 6-8 bolts securing the transmission to the engine block around the perimeter of the bellhousing. Ensure all bolts are removed before attempting to separate the transmission.
9. 9

   Separate and remove transmission
   Carefully slide the transmission straight back on the transmission jack, ensuring the torque converter remains fully seated in the transmission pump. The transmission input shaft must clear the crankshaft pilot bearing without binding. Continue pulling the transmission back until it is completely separated from the engine. Lower the transmission jack and roll it out from under the vehicle. Verify the torque converter stayed with the transmission and did not remain on the flexplate studs.
10. 10

    Inspect torque converter and crankshaft
    With the transmission removed, inspect the torque converter hub for cracks, wear grooves, or discoloration indicating overheating. Check the converter hub seal surface for scoring. Inspect the crankshaft flange for cracks, worn bolt holes, or runout. Check the rear main seal for leakage. If the seal is leaking or damaged, replace it now while access is available. Inspect the crankshaft pilot bearing if equipped.
11. 11

    Lock crankshaft and remove flexplate bolts
    Lock the crankshaft from rotating using a flywheel holding tool engaged in the ring gear teeth, or wedge a large screwdriver between the ring gear and the bellhousing opening. Remove all 8 flexplate mounting bolts in a crisscross pattern to prevent warping. Note the orientation and any shims or spacers behind the flexplate. Remove the flexplate from the crankshaft flange.
12. 12

    Inspect old flexplate and crankshaft flange
    Inspect the old flexplate for cracks around the bolt holes, ring gear damage, or warping. Cracks typically appear radiating from the bolt holes or in the thin sections near the ring gear. Check for heat discoloration indicating slippage or overheating. Clean the crankshaft flange thoroughly with brake cleaner and a wire brush, removing all old thread locker and debris. Inspect the crankshaft bolt holes for thread damage. Check crankshaft flange runout with a dial indicator if warpage is suspected; runout should not exceed 0.010 inch.
13. 13

    Install new flexplate
    Position the new flexplate onto the crankshaft flange, aligning all bolt holes. Ensure the flexplate is oriented correctly with the torque converter mounting pads facing the transmission side. If an indexing dowel or offset bolt pattern is present, ensure proper alignment. Install all 8 new flexplate bolts finger-tight. Apply medium-strength thread locker to the bolt threads as specified.
14. 14

    Torque flexplate bolts in sequence
    Lock the crankshaft using the flywheel holding tool. Torque the flexplate bolts in a crisscross star pattern to the specified torque in three stages: first to 30 lb-ft, then to 50 lb-ft, and finally to the full 63 lb-ft. This ensures even clamping force and prevents flexplate warping. Verify all bolts are properly torqued by rechecking each bolt in sequence.
    Torque spec

    Flexplate Bolts85 Nm (63 lb-ft)
15. 15

    Reinstall transmission
    Ensure the torque converter is fully seated in the transmission pump; the converter should be recessed approximately 1/2 inch behind the bellhousing face when properly seated. Apply a small amount of high-temperature grease to the torque converter hub and pilot. Position the transmission on the transmission jack and raise it into position behind the engine. Align the transmission with the engine block and slide it forward, ensuring the torque converter hub engages the crankshaft properly and the input shaft slides into the crankshaft pilot. Continue until the bellhousing contacts the engine block evenly. Install all transmission-to-engine bellhousing bolts and torque them in a crisscross pattern to specification.
    Torque spec

    Transmission-to-Engine Bolts55 Nm (41 lb-ft)
16. 16

    Install torque converter bolts
    Align the torque converter with the flexplate using the alignment marks made during disassembly. Rotate the crankshaft to access each bolt hole through the bellhousing inspection opening. Install all 4 torque converter bolts, applying medium-strength thread locker to the threads. Torque each bolt to specification in a crisscross pattern while holding the crankshaft from rotating. Rotate the crankshaft by hand to verify smooth rotation with no binding or unusual noise.
    Torque spec

    Torque Converter Bolts50 Nm (37 lb-ft)
17. 17

    Reinstall crossmember and transmission mount
    Raise the transmission slightly with the transmission jack if needed to align the mount. Position the crossmember into place and install the crossmember-to-frame bolts. Install the transmission mount-to-crossmember bolts and torque all mounting bolts to specification. Lower the transmission jack slightly to transfer the weight to the mount, then remove the transmission jack.
    Torque spec

    Mounting Bolts47 Nm (35 lb-ft)
18. 18

    Reinstall bellhousing inspection cover
    Position the bellhousing inspection cover over the opening and install the cover bolts. Torque the cover bolts to specification to ensure a proper seal and prevent rattling.
    Torque spec

    Cover Bolts16 Nm (12 lb-ft)
19. 19

    Reconnect shift linkage and electrical connections
    Reconnect the shift cable to the transmission shift lever and install the cable bracket if removed. Reconnect all electrical connectors to the transmission, including the neutral safety switch, speed sensor, and solenoid pack. Ensure all connectors are fully seated and locked.
20. 20

    Reinstall driveshaft
    Apply a small amount of grease to the transmission output shaft splines. Slide the driveshaft forward, engaging the slip yoke with the transmission output shaft. Align the driveshaft-to-differential flange using the alignment marks made during disassembly. Install the 4 flange bolts and torque them to specification in a crisscross pattern.
21. 21

    Reconnect transmission cooler lines
    Remove the plugs or caps from the transmission cooler lines. Reconnect the cooler lines to the transmission fittings and tighten securely. Ensure the lines are properly routed and secured with any retaining clips to prevent chafing or damage.
22. 22

    Reinstall exhaust system
    Position the exhaust system back into place and reconnect it at the manifold flanges and support brackets. Install all exhaust bolts and torque them to specification. Ensure adequate clearance between the exhaust and driveshaft, transmission, and body components.
23. 23

    Install new transmission filter and pan
    Install a new transmission filter into the valve body. Position a new transmission pan gasket on the pan or transmission case as specified by the gasket type. Align the transmission pan and install all pan bolts finger-tight. Torque the pan bolts in a crisscross pattern to specification to prevent warping the pan or crushing the gasket.
    Torque spec

    Gasket Bolts20 Nm (15 lb-ft)
24. 24

    Refill transmission fluid and check operation
    Add approximately 4-5 quarts of ATF+3 transmission fluid through the dipstick tube. Reinstall the rear wheels and lower the vehicle to the ground. Reconnect the negative battery cable. 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 briefly in each gear. Return to Park and check the fluid level with the engine running and at operating temperature. Add fluid as necessary to bring the level to the full mark. Check for leaks around the transmission pan, cooler lines, and bellhousing. Road test the vehicle to verify proper transmission operation and no abnormal noises from the flexplate area.

Reassembly

1. Torque all fasteners to specification using the proper sequence where indicated.
2. Use new gaskets and seals where specified.
3. Apply thread locker to flexplate and torque converter bolts as specified.
4. Verify the torque converter is fully seated in the transmission pump before installation.
5. Align all balance marks made during disassembly to maintain driveline balance.
6. Refill transmission fluid to the proper level with the engine running at operating temperature.

Verification

• Start the engine and verify no abnormal noises from the bellhousing or flexplate area.
• Check for transmission fluid leaks at the pan, cooler lines, and bellhousing.
• Verify the transmission engages all gears smoothly without slipping or harsh shifts.
• Road test the vehicle and verify smooth acceleration with no vibration or unusual noises.
• Recheck transmission fluid level after road test and top off if necessary.
• Verify the shift indicator matches the actual gear selection.
• Check that the parking brake holds and the vehicle does not move in Park on an incline.

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