Flywheel Resurface

This procedure covers removal of the transmission and clutch assembly to access and remove the flywheel for resurfacing, then reinstallation of all components.

Warnings

Tools required

Parts

• Flywheel resurfacing service × 1 — Take to machine shop - check minimum thickness specification
• Clutch disc and pressure plate kit × 1 — Use OEM specification or equivalent
• Pilot bearing × 1 — Use OEM specification
• Transmission input shaft seal × 1 — Use OEM specification
• Transmission to engine gasket/seal × 1 — Use OEM specification
• Flywheel bolts × 8 — Use new OEM bolts - torque-to-yield

Fluids

• ATF+4 — 11 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect both battery cables (negative first, then positive) to prevent electrical shorts
3. Raise vehicle on lift or securely support on jack stands at frame rails
4. Remove skid plates and belly pans if equipped
5. Allow engine and transmission to cool completely if recently driven
6. Position transmission jack under transmission for future support
7. Have transmission drain pan and fluid catch containers ready

Procedure

1. 1

   Drain transmission and transfer case fluids
   Place drain pan under transmission. Remove transmission drain plug and allow manual transmission fluid (MOPAR MS-9224 / API GL-4 synchromesh spec) to drain completely. Remove transfer case drain plug and drain fluid into separate container if you plan to reuse it. If fluid is contaminated, plan to replace with fresh ATF+4.
2. 2

   Remove driveshafts
   Mark front and rear driveshaft flanges for reinstallation alignment. Remove four bolts at each driveshaft flange connection (front driveshaft to transfer case and front axle, rear driveshaft to transfer case and rear axle). Support driveshafts and slide out of slip yokes. Plug transfer case and transmission outputs with rags or caps to prevent fluid loss and contamination.
3. 3

   Disconnect shift linkage and electrical connections
   Disconnect clutch hydraulic line at transmission slave cylinder - be prepared for fluid spillage. Disconnect transmission wiring harness connectors including reverse light switch, speed sensors, and any additional sensors. Remove shift lever boot and unbolt shift lever from transmission tower. For G56 6-speed, remove shift tower assembly completely (four bolts).
4. 4

   Remove transfer case
   Support transfer case with a jack or stand. Remove transfer case to transmission mounting nuts (typically six nuts). Carefully pry transfer case away from transmission and lower it clear. The transfer case weighs approximately 80-90 lbs, so maintain control during removal.
5. 5

   Support engine and remove crossmember
   Place jack stand or support under engine oil pan using a block of wood to distribute load. Do not support on drain plug. Ensure engine is securely supported. Remove transmission crossmember bolts and lower crossmember away from vehicle.
6. 6

   Disconnect starter and inspection cover
   Disconnect starter motor wiring. Remove starter mounting bolts and remove starter motor. Remove lower inspection cover/dust shield bolts to access flywheel and clutch assembly. This provides access to flywheel and clutch pressure plate bolts.
7. 7

   Remove transmission to engine bolts
   With transmission jack positioned securely under transmission, remove all transmission to engine mounting bolts. There are typically 6-8 bolts of varying lengths around the bell housing perimeter. Keep bolts organized by location as they may be different lengths. Ensure transmission is properly supported on jack before removing final bolts.
8. 8

   Separate and remove transmission
   Carefully slide transmission straight back away from engine. The input shaft must slide out of the pilot bearing and clutch disc without binding. Keep transmission level during removal. Once input shaft clears clutch, lower transmission on jack and roll out from under vehicle. The transmission weighs approximately 200-250 lbs.
9. 9

   Remove clutch pressure plate and disc
   Install flywheel holding tool or lock flywheel using starter ring gear. Mark pressure plate position on flywheel for reinstallation reference. Gradually loosen pressure plate bolts in a star pattern, turning each bolt 1-2 turns at a time to evenly release spring pressure. Remove all bolts and carefully remove pressure plate and clutch disc. Inspect clutch disc for wear, oil contamination, or damage.
10. 10

    Remove flywheel bolts and flywheel
    With flywheel locked using holding tool, remove all eight flywheel mounting bolts. These are high-strength torque-to-yield bolts and must be replaced - do not reuse. Carefully remove flywheel from crankshaft. The flywheel for the 5.9L Cummins weighs approximately 50-60 lbs. Inspect crankshaft flange and dowel pins for damage.
11. 11

    Inspect and prepare flywheel for resurfacing
    Clean flywheel thoroughly with brake cleaner. Inspect for cracks, heat checking, hot spots, or severe scoring. Measure flywheel thickness at multiple points if possible. Take flywheel to qualified machine shop for resurfacing. Provide minimum thickness specification from service manual. Machine shop should check for warpage, resurface clutch surface, and verify thickness is within specification.
12. 12

    Clean and inspect mating surfaces
    While flywheel is at machine shop, thoroughly clean crankshaft flange with brake cleaner. Remove any gasket material, oil residue, or debris. Inspect crankshaft dowel pins for damage. Clean bell housing interior and inspect pilot bearing bore. Remove and replace pilot bearing using appropriate driver or installation tool. Ensure new pilot bearing is properly seated and lubricated per manufacturer instructions.
13. 13

    Install resurfaced flywheel
    Clean resurfaced flywheel with brake cleaner to remove any machining oil or residue. Align flywheel on crankshaft dowel pins. Install NEW flywheel bolts (do not reuse old torque-to-yield bolts). Lock flywheel with holding tool. Tighten flywheel bolts in star pattern in stages to final specification per service manual (verify exact value; 5.9L Cummins flywheel bolts are commonly specified around 137 ft-lbs / 185 Nm). Verify flywheel is seated flush against crankshaft flange.
14. 14

    Install new clutch assembly
    Clean pressure plate mounting surface on flywheel. Install new clutch disc on flywheel with raised hub portion facing transmission (away from flywheel). Insert clutch alignment tool through disc and into pilot bearing to center disc. Position new pressure plate on flywheel, aligning dowel pins or previous reference marks. Start all pressure plate bolts and tighten gradually in star pattern to specification per clutch kit instructions (typically 37-40 ft-lbs). Remove alignment tool only after pressure plate is fully torqued.
15. 15

    Reinstall transmission
    Apply light coat of high-temp grease to transmission input shaft splines (do not over-grease). Install new transmission input shaft seal if worn. Position transmission on jack and raise into position. Ensure clutch alignment tool is still in place to guide input shaft. Carefully slide transmission forward, ensuring input shaft enters pilot bearing and clutch disc splines without binding. Align transmission to engine and install all mounting bolts hand-tight first, then torque in star pattern to specification (verify exact value against service manual for the G56/Cummins application). Remove clutch alignment tool through starter opening.

Reassembly

1. Install transmission crossmember and torque mounting bolts to specification
2. Install transfer case with new gasket or sealant as specified, torque mounting nuts properly
3. Reinstall starter motor and dust shield/inspection cover
4. Reconnect all electrical connectors to transmission and transfer case sensors
5. Install shift lever assembly and reconnect shift linkage with proper adjustment
6. Reconnect clutch hydraulic line and bleed clutch system if necessary
7. Install front and rear driveshafts, aligning reference marks made during disassembly
8. Torque all driveshaft flange bolts to specification in star pattern
9. Refill transmission with 8.0 quarts ATF+4 through fill plug until fluid reaches proper level
10. Refill transfer case with 2.5 quarts ATF+4
11. Reinstall skid plates and belly pans
12. Reconnect battery cables (positive first, then negative)
13. Lower vehicle to ground

Verification

• Start engine and verify no unusual noises from bell housing area
• Test clutch pedal operation - should feel firm with proper engagement point
• Check for fluid leaks at transmission, transfer case, and hydraulic clutch line
• With engine running, verify clutch fully disengages by attempting to shift through all gears with vehicle stationary
• Perform test drive including all gears - verify smooth shifting and no clutch slippage under load
• Check transmission and transfer case fluid levels after test drive and top off if necessary
• Listen for any abnormal vibrations or noises that could indicate flywheel imbalance or improper installation
• Verify no clutch chatter during engagement and smooth take-off operation

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