Replace the automatic locking hub assembly on the front axle of a 2014 Ram 2500 4WD with 6.7L Cummins Diesel engine.

Warnings

Tools required

Parts

• Automatic locking hub assembly × 1 — Use OEM specification
• Axle nut cotter pin × 1 — Use OEM specification
• Hub mounting bolt set × 1 — Use OEM specification
• Front differential cover gasket × 1 — Use OEM specification if removing cover

Fluids

• 75W-90 GL-5 Gear Oil — 1.5 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Chock rear wheels securely
3. Loosen wheel lug nuts while vehicle is on ground
4. Raise front of vehicle and support on jack stands rated for vehicle weight
5. Remove front wheel on side being serviced
6. Allow differential to cool completely if vehicle was recently driven

Procedure

1. 1

   Remove axle nut and cotter pin
   Remove the cotter pin from the axle nut using pliers or a removal tool. Using a 36mm socket and breaker bar, loosen and remove the axle nut. Note that this nut is torqued to 250 Nm and will require significant force. Set the nut aside as it should be replaced with a new one during reassembly.
2. 2

   Remove brake caliper and rotor
   Remove the brake caliper mounting bolts and hang the caliper securely from the suspension using a wire or bungee cord to avoid stress on the brake hose. Slide the brake rotor off the hub. If the rotor is stuck, use a rubber mallet to tap it free.
3. 3

   Mark and remove front driveshaft (if necessary for access)
   If access to the hub is restricted, mark the front driveshaft orientation to the front pinion flange with a paint marker or punch marks. Remove the four U-joint strap bolts at the differential using a socket wrench. Support the driveshaft and carefully lower it away from the pinion flange. Secure the driveshaft out of the way.
   Torque spec

   Driveshaft U-Joint Straps20 Nm (15 lb-ft)
4. 4

   Position drain pan
   Place a drain pan with at least 2 quart capacity beneath the locking hub assembly. When the hub is removed, gear oil from the front differential will drain out through the axle tube opening.
5. 5

   Remove locking hub mounting bolts
   Locate the mounting bolts securing the locking hub assembly to the steering knuckle. There are typically 6 bolts arranged in a circular pattern. Remove all mounting bolts using the appropriate socket. Keep track of bolt locations if they are different lengths.
   Torque spec

   Mounting Bolts37 Nm (27 lb-ft)
6. 6

   Remove old locking hub assembly
   Carefully pull the locking hub assembly straight off the axle shaft. The assembly may be tight due to O-ring seals. Use a pry bar if necessary, being careful not to damage the steering knuckle mounting surface. Allow gear oil to drain into the pan. Remove and inspect the O-ring seals on the hub and axle shaft.
7. 7

   Clean mounting surfaces
   Thoroughly clean the steering knuckle mounting surface and the axle shaft splines using a wire brush and brake cleaner. Remove all old gasket material, dirt, and gear oil residue. Inspect the axle shaft splines for wear or damage. Check the steering knuckle bore for scoring or damage.
8. 8

   Prepare new locking hub assembly
   Unpack the new locking hub assembly and verify it matches the original. Install new O-ring seals if provided separately, lubricating them lightly with gear oil. Inspect the internal splines of the new hub to ensure they are clean and undamaged. Apply a light coat of gear oil to the axle shaft splines.
9. 9

   Install new locking hub assembly
   Align the splines of the locking hub assembly with the axle shaft splines. Carefully slide the hub assembly onto the axle shaft, ensuring proper engagement. Push the hub fully onto the steering knuckle until it seats against the mounting surface. Verify the hub is fully seated before installing bolts.
10. 10

    Install and torque mounting bolts
    Apply medium-strength thread locker to the threads of the mounting bolts. Install all mounting bolts finger-tight in a star pattern to ensure even seating. Using a torque wrench, tighten the mounting bolts in a star pattern to the specified torque of 37 Nm (27 lb-ft). Make a second pass in the same pattern to verify torque.
    Torque spec

    Mounting Bolts37 Nm (27 lb-ft)
11. 11

    Reinstall brake rotor and caliper
    Slide the brake rotor back onto the hub assembly. Reinstall the brake caliper onto the mounting bracket and torque the caliper bolts to manufacturer specification. Ensure the brake hose is not twisted or kinked.
12. 12

    Install and torque axle nut
    Install the new axle nut onto the axle shaft threads. Using a torque wrench and 36mm socket, torque the axle nut to 250 Nm (184 lb-ft). Install a new cotter pin through the axle shaft hole and bend the ends to secure. If using a staked nut design, stake the nut collar into the axle shaft groove using a punch.
    ⚠Always use a new cotter pin or properly stake the nut as specified - this is a critical safety fastener
    Torque spec

    Axle Nut250 Nm (184 lb-ft)
13. 13

    Reinstall driveshaft (if removed)
    If the front driveshaft was removed, align the marked reference points on the driveshaft yoke and pinion flange. Install the U-joint strap bolts and tighten evenly in a crossing pattern to 20 Nm (15 lb-ft) using a torque wrench.
    Torque spec

    Driveshaft U-Joint Straps20 Nm (15 lb-ft)
14. 14

    Refill front differential
    Using a fluid pump or squeeze bottle, add 75W-90 GL-5 gear oil through the differential fill plug opening until oil begins to drip from the fill hole. Install and tighten the fill plug. Approximately 1.5 quarts should be required to bring the level back to specification.
15. 15

    Reinstall wheel and lower vehicle
    Mount the wheel onto the hub and install the lug nuts. Tighten lug nuts in a star pattern by hand. Lower the vehicle until the tire just contacts the ground. Using a torque wrench, torque the lug nuts to 140 Nm (103 lb-ft) in a star pattern. Fully lower the vehicle and remove jack stands.
    Torque spec

    Wheel Lug Nuts140 Nm (103 lb-ft)

Reassembly

1. Verify all fasteners have been properly torqued using specified values and patterns
2. Check for any gear oil leaks around the locking hub mounting surface
3. Ensure the axle nut cotter pin is properly installed and secured
4. Verify brake caliper and rotor are properly installed and secured

Verification

• Start the vehicle and shift the transfer case through all positions (2H, 4H, 4L) to verify locking hub engagement
• Test drive the vehicle in 4WD mode at low speed and verify proper engagement without binding or unusual noises
• Listen for clicking or grinding noises from the hub during turns which could indicate improper installation
• After test drive, inspect the locking hub area for any gear oil leaks
• Verify the front axle engages and disengages properly when shifting between 2WD and 4WD modes
• Recheck wheel lug nut torque after 50-100 miles of driving

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