Transmission R&R - Automatic

Complete removal and reinstallation of the automatic transmission on a 1994-2007 Dodge Ram 2500 with 5.9L Cummins diesel and 4WD, including transfer case separation and torque converter handling.

Warnings

Tools required

Parts

• Transmission pan gasket × 1 — Use OEM specification
• Transmission drain plug washer × 1 — Use OEM specification
• Transmission filter kit × 1 — Use OEM specification
• Transfer case gasket or RTV sealant × 1 — Mopar RTV or equivalent
• Transmission cooler line O-rings × 2 — Use OEM specification
• Transmission crossmember bushings (if worn) × 2 — Inspect before replacement

Fluids

• Mopar ATF+4 — 14 qt

Preparation

1. Park vehicle on level surface and set parking brake firmly
2. Disconnect both battery cables (negative first, then positive)
3. Raise vehicle and support securely on jack stands at frame rails
4. Remove skid plates and belly pans if equipped
5. Mark front and rear driveshaft positions relative to yokes with paint pen for proper alignment on reinstallation
6. Place drain pan under transmission and drain fluid via drain plug
7. Allow transmission to cool completely if vehicle was recently operated

Procedure

1. 1

   Remove transfer case skid plate and drain fluids
   Remove transfer case skid plate mounting bolts. The transmission pan on these units typically has no factory drain plug; loosen the pan bolts progressively and lower one corner to drain fluid into the pan, then remove the pan. Remove transfer case drain plug and drain transfer case fluid into separate container. Install drain plugs with new washers hand-tight for now.
   Torque spec

   Drain Plug34 Nm (25 lb-ft)
2. 2

   Disconnect driveshafts
   Remove rear driveshaft from transfer case output yoke by removing four U-joint strap bolts. Support driveshaft and slide rearward out of transfer case. Remove front driveshaft from transfer case front output using same method. Cap or plug transfer case openings to prevent contamination. Secure driveshafts out of work area.
3. 3

   Disconnect electrical connections and shift linkage
   Disconnect transmission range sensor connector, speed sensor connectors, and solenoid pack connector from passenger side of transmission. Disconnect shift linkage at transmission lever by removing retaining clip. Disconnect transfer case electrical connectors and vent tube. Label all connections for proper reassembly.
4. 4

   Remove transmission cooler lines
   Place drain pan under transmission cooler line connections at transmission case. Use appropriate flare nut wrench to disconnect cooler lines from transmission. Cap or plug lines and transmission ports immediately to prevent contamination. Note routing of lines for reinstallation.
   ⚠Cooler lines may retain pressurized fluid. Loosen slowly and have rags ready to catch spillage.
5. 5

   Remove transmission crossmember
   Support transmission with transmission jack positioned securely under transmission pan. Remove two nuts securing transmission mount to crossmember. Remove four or six bolts (depending on year) securing crossmember to frame rails. Carefully lower and remove crossmember. Inspect mount bushings and replace if deteriorated.
6. 6

   Separate transfer case from transmission
   Support transfer case with second transmission jack or suitable support. Remove the mounting nuts/bolts securing transfer case to transmission adapter housing (verify count and size — typically six nuts on studs for the NV241 series). Carefully slide transfer case rearward off transmission output shaft, maintaining level position. Remove transfer case gasket material from both mating surfaces.
   ⚠Transfer case weighs approximately 90-100 lbs. Ensure adequate support before removing final mounting bolt.
7. 7

   Remove starter motor
   Disconnect wiring from starter solenoid and motor. Remove two or three mounting bolts securing starter to bellhousing (typically 15mm). Remove starter motor and set aside. Inspect starter gear for damage and replace if necessary.
8. 8

   Access and mark torque converter
   Through starter opening or inspection cover, rotate engine crankshaft to access torque converter bolts. Mark torque converter position relative to flexplate with paint pen for balanced reinstallation. Remove dust cover from bellhousing if present by removing cover screws.
9. 9

   Remove torque converter bolts
   Using socket through starter opening or bellhousing access, remove the torque converter to flexplate bolts (verify count — typically four on 47RE/48RE) while rotating crankshaft for access to each. Push torque converter slightly toward transmission to disengage from flexplate. Secure torque converter to transmission using safety wire or strap to prevent falling during transmission removal.
   ⚠Do not rotate engine using crankshaft bolt on Cummins. Use flywheel access or rotate via alternator belt with care.
   Torque spec

   Flywheel Bolts95 Nm (70 lb-ft)
10. 10

    Remove transmission bellhousing bolts
    Install engine support bar across engine bay or use hoist with load leveler attached to engine lifting eyes to support engine weight. Remove all bellhousing to engine block mounting bolts. On Cummins models, there are typically six to eight bolts of varying lengths around perimeter. Note bolt locations and lengths for proper reinstallation. Upper bolts may require extensions or universal joint sockets.
    ⚠️Engine must be properly supported before removing final bellhousing bolts. Unsupported engine can shift and cause severe injury.
11. 11

    Remove transmission assembly
    Verify all electrical connections, cooler lines, linkages, and mounting bolts are disconnected. Double-check torque converter is secured to transmission. With transmission jack positioned securely under transmission pan, carefully slide transmission rearward away from engine, maintaining level position. Transmission must move straight back approximately 2-3 inches before clearing dowel pins and bellhousing. Once clear of engine, lower transmission on jack and roll from under vehicle. Verify torque converter remained with transmission.
    ⚠Maintain transmission level during removal to prevent torque converter from falling out. If converter slides forward, reinstall and secure before proceeding.
12. 12

    Inspect and prepare for installation
    Inspect flexplate for cracks, heat damage, or missing teeth. Check flywheel ring gear condition. Inspect crankshaft rear seal for leaks. Clean bellhousing mating surface on engine block. If installing used or rebuilt transmission, verify torque converter is fully seated by measuring depth from bellhousing face to converter ear lugs (should be approximately 1/2 inch recessed minimum). Replace transmission filter and pan gasket if servicing existing transmission.
    Torque spec

    Transmission Pan Bolts12 Nm (9 lb-ft)
13. 13

    Install transmission assembly
    Apply thin coat of high-temp grease to torque converter hub and pilot. Ensure torque converter is fully seated in transmission pump by rotating while applying light inward pressure - you should feel three distinct engagement points. Position transmission on jack and raise into position. Carefully align transmission with engine block dowel pins while maintaining level position. Slide transmission forward, rotating torque converter slightly to engage flexplate pilot. Continue sliding forward until bellhousing contacts engine block completely. Do not use bolts to draw transmission to engine.
    ⚠️Never use bellhousing bolts to pull transmission to engine. If transmission does not slide forward easily, torque converter is not properly seated or alignment is incorrect. Forcing installation will damage transmission pump.
14. 14

    Install bellhousing bolts and torque converter
    Install all bellhousing to engine block mounting bolts in their original locations, starting with upper bolts. Thread all bolts hand-tight before torquing. Torque bellhousing mounting bolts to specification. Rotate engine to access torque converter bolt holes through starter opening. Align torque converter to flexplate using alignment marks made during removal. Install and torque four converter to flexplate bolts in star pattern.
    Torque spec

    Flywheel Bolts95 Nm (70 lb-ft)
15. 15

    Reinstall transfer case and remaining components
    Apply new gasket or RTV sealant bead to transfer case mating surface. Position transfer case on jack and align with transmission output shaft and adapter housing. Slide transfer case forward onto output shaft, ensuring proper spline engagement. Install and torque transfer case mounting bolts. Install transmission crossmember and torque mounting hardware. Install starter motor and torque mounting bolts. Reconnect all electrical connections, shift linkage, and cooler lines with new O-rings. Install driveshafts aligned with original marks. Reinstall skid plates.
16. 16

    Refill fluids and perform initial checks
    Torque transmission drain plug with new washer. Through fill tube, add approximately 6-7 quarts of the specified ATF initially (Mopar ATF+4 for 1998+; earlier 1994-1997 units originally specified ATF+3/Mopar 7176 — verify by model year). Start engine and allow to idle. With parking brake applied and foot on brake pedal, shift through all gear ranges, pausing 2-3 seconds in each position. Return to Park. Check fluid level with engine running and at operating temperature - add fluid as needed to bring to full mark on dipstick. Total dry-fill capacity is approximately 17-19 quarts including the torque converter and cooler; always verify final level on the dipstick at operating temperature. Refill transfer case with approximately 2 quarts Mopar ATF+4 (verify exact capacity and fluid spec for the specific transfer case model). Torque fill plug.
    Torque spec

    Drain Plug34 Nm (25 lb-ft)

    Fill Plug34 Nm (25 lb-ft)

Reassembly

1. Ensure all bellhousing bolts are torqued to proper specification - mixing up bolt locations or using wrong torque can cause transmission failure
2. Verify torque converter to flexplate bolts are installed and torqued properly - missing bolts will cause catastrophic failure
3. Double-check all electrical connectors are fully seated and locked - transmission will not shift properly with loose connections
4. Confirm driveshafts are installed in original orientation using alignment marks to prevent driveline vibration
5. Verify transmission cooler lines are properly routed and not contacting exhaust or driveshaft

Verification

• Start engine and verify no fluid leaks from transmission pan, drain plug, cooler lines, or case mating surfaces
• With parking brake set and foot on brake, verify transmission shifts smoothly through all gear ranges without harsh engagement or slipping
• Test drive vehicle and verify smooth acceleration, proper shift points, and no abnormal noises or vibrations
• Verify 4WD engagement operates properly through all transfer case ranges
• After test drive, recheck transmission fluid level hot with engine running and top off if necessary
• Inspect underneath vehicle for any fluid drips or leaks after 50-100 miles of operation
• Verify no check engine lights or transmission fault codes are present using scan tool

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