Flexplate

This procedure covers the removal and replacement of the flexplate on a 2007 Ram 3500 with the 5.9L Cummins diesel engine and 4WD, requiring transmission removal to access the flexplate.

Warnings

Tools required

Parts

• Flexplate × 1 — Use OEM specification for 5.9L Cummins
• Flexplate bolts × 8 — Use OEM specification, typically M11 x 1.5
• Transmission to engine bolts (inspect and replace if damaged) × 1 — Use OEM specification
• Transmission fluid filter and gasket kit × 1 — Use OEM or equivalent
• Transmission pan gasket × 1 — Use OEM or equivalent

Fluids

• ATF+4 — 20 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect both battery terminals, negative first
3. Raise vehicle and support securely on heavy-duty jack stands at frame rails
4. Remove skid plates and belly pans if equipped
5. Allow transmission to cool if vehicle was recently operated
6. Place drain pan under transmission and drain transmission fluid from pan
7. Remove driveshaft(s) - mark orientation for reinstallation
8. Remove transfer case if equipped (4WD model)
9. Disconnect transmission cooler lines and cap to prevent contamination
10. Disconnect shift linkage, electrical connectors, and speedometer cable from transmission
11. Support engine with engine support bar or place jack under oil pan with wood block

Procedure

1. 1

   Remove transmission crossmember
   Support transmission with transmission jack. Remove the bolts securing the transmission crossmember to the frame. Carefully lower the transmission jack slightly to allow access to the upper bellhousing bolts. Do not let the transmission hang unsupported on the input shaft.
2. 2

   Disconnect torque converter from flexplate
   Remove the inspection cover or dust shield from the lower bellhousing to access the torque converter bolts. Rotate the crankshaft using a socket on the crankshaft pulley bolt to bring each torque converter bolt into view through the inspection opening. Remove all torque converter to flexplate bolts (verify count against factory service manual; typically 4 on the 48RE). Mark the torque converter orientation to the flexplate if visible.
3. 3

   Remove bellhousing bolts
   Remove all bellhousing to engine block bolts. There are typically 6-8 bolts around the perimeter of the bellhousing. Note the location of different length bolts and any brackets or grounds attached. Support the transmission weight fully on the transmission jack before removing the final bolts.
4. 4

   Separate and remove transmission
   Carefully slide the transmission straight back away from the engine, ensuring the torque converter stays with the transmission and does not fall. The input shaft must clear the crankshaft pilot bearing. Move slowly and keep the transmission level. Once clear of the engine, lower the transmission jack and roll the transmission out from under the vehicle. Install a torque converter holding tool or secure converter to prevent it from falling out.
5. 5

   Inspect and mark flexplate orientation
   With the transmission removed, thoroughly inspect the flexplate for cracks, especially around the bolt holes and in the area between the crankshaft mounting surface and the torque converter mounting surface. Use a marker or paint pen to mark the flexplate position relative to the crankshaft flange before removal to maintain engine balance.
6. 6

   Lock crankshaft rotation
   Use a flywheel holding tool or wedge a large pry bar between the flexplate teeth and the engine block (through the starter opening) to prevent crankshaft rotation. Be careful not to damage flexplate teeth if reusing. Ensure the tool or pry bar is secure before attempting to loosen bolts.
7. 7

   Remove flexplate bolts
   Remove all flexplate to crankshaft bolts in a cross pattern to prevent warping. There are typically 8 bolts securing the flexplate to the crankshaft. These bolts are high-strength and may require significant force to break loose. Inspect the old bolts for thread damage or stretching; consult the factory service manual to determine whether these bolts are reusable or single-use before discarding.
8. 8

   Remove and inspect flexplate
   Carefully remove the flexplate from the crankshaft flange. Inspect the crankshaft flange surface for damage, burrs, or debris. Clean the crankshaft flange thoroughly with brake cleaner and a lint-free cloth. Inspect the rear main seal for leaks; now is an opportune time to replace if needed. Check the pilot bearing or bushing in the crankshaft for wear.
9. 9

   Prepare new flexplate for installation
   Unpack the new flexplate and inspect for shipping damage. Compare the new flexplate to the old unit to confirm correct part number and bolt pattern. Clean the mounting surface of the new flexplate. Apply thread locker to the new flexplate bolt threads only if specified by the factory service manual, and use the exact grade (medium or high strength) called out; many replacement bolts come with pre-applied threadlocker and require none.
10. 10

    Install flexplate to crankshaft
    Align the new flexplate to the crankshaft flange using the alignment marks made during removal or according to the balance marks on the flexplate and crankshaft (if present). Install all new flexplate bolts finger tight. Ensure the flexplate is fully seated against the crankshaft flange with no gaps.
11. 11

    Torque flexplate bolts
    With the crankshaft locked in position, torque the flexplate bolts in a cross pattern. Since no specific torque specs are provided in the database, consult the factory service manual for exact specifications (approximately 101 ft-lbs / 137 Nm for the 5.9L Cummins flexplate bolts). Perform torque sequence in multiple stages: first to 50% of final torque, then to 100% in cross pattern. Verify all bolts are properly torqued.
12. 12

    Reinstall transmission
    Position the transmission on the transmission jack and roll under the vehicle. Apply a small amount of high-temperature grease to the input shaft splines. Ensure the torque converter is fully seated in the transmission pump (should be recessed approximately 1/2 inch from bellhousing face). Carefully align the transmission with the engine block and slide forward, guiding the input shaft into the crankshaft pilot bearing. The torque converter pilot must engage the crankshaft center. Do not force; wiggle and rotate slightly if binding occurs.
13. 13

    Install bellhousing and torque converter bolts
    Install all bellhousing to engine block bolts and tighten in a cross pattern. Reinstall any brackets or ground straps removed earlier. Rotate the crankshaft to align the torque converter mounting holes with the flexplate. Install all torque converter to flexplate bolts finger tight, then torque to specification in a cross pattern. Rotate the engine several full revolutions by hand to verify smooth operation and proper clearances.
14. 14

    Reinstall transmission crossmember and components
    Raise the transmission into final position and install the transmission crossmember. Torque crossmember bolts to specification. Remove the transmission jack. Reconnect all shift linkage, electrical connectors, speedometer cable, and transmission cooler lines. Install the transfer case if equipped, ensuring proper alignment and torque of mounting bolts.
15. 15

    Complete final assembly
    Reinstall the driveshaft(s) according to alignment marks made during removal. Install inspection cover or dust shield. Reinstall skid plates and belly pans. Refill transmission with ATF+4 to proper level. A pan-only service typically requires about 4-6 quarts, while a full dry fill (converter drained) is approximately 17-19 quarts. Check dipstick while running in park at operating temperature and add gradually to avoid overfilling. Install new transmission filter if accessible. Reconnect battery terminals (positive first). Remove jack stands and lower vehicle.

Reassembly

1. Ensure all electrical connectors, shift linkage, and cooler lines are properly secured
2. Verify all bellhousing bolts and crossmember bolts are torqued to specification
3. Check that driveshaft(s) are installed with proper phasing and alignment marks matched
4. Confirm torque converter bolts are accessible and properly torqued through inspection opening
5. Double-check transmission fluid level when engine is at operating temperature in park

Verification

• Start engine and check for unusual noises or vibrations that could indicate improper flexplate installation
• With engine running, verify transmission engages smoothly in all gears
• Check for transmission fluid leaks around bellhousing and cooler line connections
• Test drive vehicle and listen for abnormal sounds during acceleration and deceleration
• Verify no grinding, clicking, or knocking sounds from bellhousing area during operation
• Re-check transmission fluid level after test drive and top off if necessary
• Inspect flexplate installation through inspection cover opening to verify proper bolt tightness and no visible cracks

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