Transmission R&R - Manual

Complete removal and reinstallation of the NV4500 or G56 manual transmission from a 2007 Ram 3500 with 5.9L Cummins diesel engine and 4WD.

Warnings

Tools required

Parts

• Transmission input shaft seal × 1 — Use OEM specification
• Clutch kit (disc, pressure plate, throwout bearing) × 1 — Use OEM or equivalent for 5.9L Cummins
• Pilot bearing × 1 — Use OEM specification
• Transmission-to-engine gasket or RTV sealant × 1 — Use OEM specification
• Shifter tower boot/seal × 1 — Use OEM specification
• Clutch slave cylinder × 1 — Use OEM specification if internal type
• Transfer case output seal (rear) × 1 — Use OEM specification

Fluids

• ATF+4 transmission fluid — 8 qt
• ATF+4 transfer case fluid — 2.5 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect both battery negative terminals to prevent electrical shorts
3. Raise vehicle using floor jack and support securely on jack stands at frame rails (minimum 24 inches ground clearance recommended)
4. Remove skid plates if equipped to access transmission and transfer case
5. Drain transmission fluid by removing drain plug or accessing fill/drain from shifter opening
6. Drain transfer case fluid using drain plug
7. Position fluid catch pans under transmission bell housing area and transfer case

Procedure

1. 1

   Remove driveshafts
   Mark front and rear driveshaft flanges to their yokes with paint pen for reinstallation alignment. Remove rear driveshaft by unbolting four bolts at rear axle flange and four bolts at transfer case flange. Remove front driveshaft by unbolting from front differential and transfer case. Support driveshafts and lower carefully to avoid damaging CV joints or U-joints. Store away from work area.
2. 2

   Disconnect shift linkage and electrical connections
   Remove shift tower/boot from transmission top by removing mounting bolts (typically 4-6 bolts). Lift shifter assembly up and out of transmission. Disconnect backup light switch connector and vehicle speed sensor connector from transmission case. Disconnect any ground straps attached to transmission bell housing. If equipped with G56 transmission, disconnect reverse lockout solenoid connector.
3. 3

   Disconnect clutch hydraulic line
   Locate clutch hydraulic line connection at bell housing (external slave cylinder) or internal connection point. For external slave cylinder, remove mounting bolts and disconnect hydraulic line, allowing fluid to drain into catch pan. For internal slave cylinder (common on G56), disconnect hydraulic line at bell housing entry point. Cap or plug line to minimize fluid loss and contamination.
4. 4

   Support transfer case and separate from transmission
   Position a second transmission jack or support fixture under transfer case. Remove transfer case-to-transmission mounting bolts (typically 6 bolts around adapter housing). Carefully slide transfer case rearward off transmission output shaft, supporting weight on jack. Lower transfer case slightly and move away from transmission work area but keep supported if reinstalling same unit.
5. 5

   Remove transmission crossmember
   With transmission jack positioned under transmission (not yet supporting full weight), remove transmission mount-to-crossmember fasteners. Remove crossmember-to-frame bolts on both sides. Carefully lower and remove crossmember from vehicle. Inspect transmission mount rubber isolator for deterioration and replace if cracked or compressed.
6. 6

   Disconnect exhaust system if necessary
   Depending on exhaust configuration, loosen or remove exhaust pipe hangers near transmission to provide clearance. On some configurations, the front exhaust pipe may need to be unbolted from turbo or exhaust manifold to provide adequate clearance for transmission removal. Support exhaust with wire or strap to prevent damage.
7. 7

   Remove starter motor
   Disconnect electrical connections from starter solenoid (battery cable and trigger wire). Remove starter mounting bolts (typically 3 bolts). Carefully remove starter motor from bell housing, maneuvering past exhaust and other components. Inspect starter for wear if reinstalling; note that Cummins starters are heavy-duty units.
8. 8

   Remove bell housing to engine block bolts
   Position transmission jack securely under transmission, taking up weight but not lifting. Remove all bell housing-to-engine block bolts (typically 6-8 bolts of varying lengths). Note bolt locations and lengths for reinstallation. Some upper bolts may require extension or universal joint socket to access. Inspect for any additional brackets or ground straps that may be attached.
9. 9

   Separate transmission from engine
   With all bolts removed and transmission supported on jack, carefully slide transmission straight rearward, keeping input shaft aligned with clutch assembly. Continue sliding until input shaft clears clutch disc and pilot bearing. Once clear of engine (approximately 12-16 inches), carefully lower and tilt transmission as needed to maneuver past crossmembers and exhaust. Guide transmission out from under vehicle, maintaining control with transmission jack at all times.
10. 10

    Inspect clutch and flywheel
    With transmission removed, inspect clutch disc for wear, contamination, or glazing. Check pressure plate fingers for even wear and proper height. Inspect flywheel surface for heat cracks, scoring, or hot spots. Measure flywheel runout with dial indicator if available (should be less than 0.010 inch). Remove and replace pilot bearing in crankshaft. If clutch shows significant wear or if over 100k miles, strongly consider complete clutch replacement while transmission is out.
11. 11

    Clean and prepare mating surfaces
    Thoroughly clean transmission bell housing mating surface and engine block mating surface using wire brush and solvent. Remove all old gasket material or RTV residue. Inspect bell housing for cracks, especially around mounting bolt holes. Clean input shaft splines with solvent and light wire brush. Inspect input shaft seal in transmission front bearing retainer and replace if showing any seepage. Apply light coating of high-temperature grease to input shaft splines.
12. 12

    Install clutch assembly (if replacing)
    If installing new clutch, position clutch disc against flywheel with proper orientation (marked side typically faces pressure plate, or 'flywheel side' stamping). Insert clutch alignment tool through clutch disc hub and into pilot bearing to center disc. Position pressure plate over clutch disc and align with dowel pins on flywheel. Install pressure plate bolts hand-tight, then torque in star pattern per clutch manufacturer specifications. Remove alignment tool only after pressure plate is fully secured.
13. 13

    Reinstall transmission to engine
    Apply small amount of high-temperature grease to input shaft splines and clutch spline hub. Position transmission on transmission jack and raise into position. Carefully align transmission input shaft with clutch disc splines and pilot bearing. Slide transmission forward slowly, ensuring input shaft enters pilot bearing smoothly. If resistance is felt, slightly rotate transmission output shaft to help splines align. Do not force or use bolts to draw transmission to engine. Once transmission is fully seated against engine block with no gap, install all bell housing bolts hand-tight, then torque in star pattern.
14. 14

    Reinstall remaining components
    Reinstall starter motor and torque mounting bolts. Reconnect starter electrical connections. Install transmission crossmember and torque frame bolts, then install transmission mount and torque fasteners. Reconnect clutch hydraulic line and slave cylinder, torquing mounting bolts. Reconnect all electrical connectors (backup light switch, VSS, reverse lockout solenoid if equipped). Reattach transfer case to transmission using new gasket or RTV, torquing mounting bolts in star pattern. Reinstall front and rear driveshafts, aligning marks made during disassembly and torquing flange bolts.
15. 15

    Refill fluids and final checks
    Install shifter tower with new boot/seal and torque mounting bolts. Fill transmission with the manufacturer-specified manual transmission fluid (G56 uses Mopar/Pentosin GL-4 75W-85 MTF, approximately 4.4 quarts) through the fill plug; verify exact fluid type and capacity against the service manual. Fill transfer case with approximately 2.0 quarts ATF+4 (verify exact capacity against service manual). Reinstall skid plates if equipped. Bleed the clutch hydraulic system per the manufacturer procedure for the internal concentric slave cylinder (bleed at the hydraulic line fitting/master cylinder), pumping the clutch pedal until a firm pedal is achieved with no air bubbles. Reconnect battery negative terminals. Lower vehicle from jack stands.

Reassembly

1. Torque all fasteners to manufacturer specifications; consult service manual for specific values not provided in database
2. Ensure driveshaft alignment marks are matched to prevent vibration
3. Verify all electrical connectors are fully seated and locked
4. Double-check that transmission and transfer case are filled to proper levels before operation
5. Ensure clutch pedal has proper free play after bleeding hydraulic system (typically 1/2 to 1 inch)

Verification

• Start engine and verify no unusual noises from transmission or bell housing area
• With engine running and clutch pedal depressed, verify smooth shifting into all gears
• Test drive vehicle and verify proper clutch engagement and disengagement
• Check for fluid leaks around bell housing, transmission case, transfer case, and driveshaft flanges
• Verify backup lights function properly in reverse gear
• Confirm no driveline vibration during test drive at various speeds
• Recheck transmission and transfer case fluid levels after test drive

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