CV Axles - Front Pair

This procedure covers the removal and replacement of both front CV axles on a 2007 Ram 3500 with 5.9L Cummins diesel and 4WD, requiring front differential fluid drain and refill.

Warnings

Tools required

Parts

• Front CV axle - driver side × 1 — Use OEM specification or heavy-duty aftermarket for Cummins diesel
• Front CV axle - passenger side × 1 — Use OEM specification or heavy-duty aftermarket for Cummins diesel
• Front axle hub nut × 2 — Replace if damaged or if cotter pin style
• Differential drain plug gasket × 1 — Copper or aluminum crush washer
• Differential fill plug gasket × 1 — Copper or aluminum crush washer

Fluids

• 75W-90 synthetic gear oil — 3.5 qt

Preparation

1. Park vehicle on level surface and set parking brake firmly
2. Place wheel chocks behind rear wheels
3. Loosen front wheel lug nuts while vehicle is on ground (do not remove)
4. Using breaker bar and 36mm socket, loosen both front axle hub nuts while vehicle is on ground with full weight on wheels (break torque only, do not remove)
5. Raise front of vehicle with floor jack and support securely on jack stands under frame rails
6. Remove front wheels completely
7. Position large drain pan under front differential

Procedure

1. 1

   Remove axle hub nuts
   With vehicle raised and supported, remove the front wheel and access the unit bearing hub assembly. Remove the axle shaft nut/hub bearing retaining bolts as applicable for the solid axle. Clean the axle shaft splines with a wire brush.
2. 2

   Disconnect tie rod ends (if required for clearance)
   On the passenger side, you may need to disconnect the tie rod end from the steering knuckle for CV axle clearance. Remove the cotter pin and castle nut, then use a tie rod separator or pickle fork to separate the tie rod end from the knuckle. Note the position for reassembly.
3. 3

   Support the brake caliper and rotor assembly
   Remove the brake caliper and rotor to access the unit bearing hub assembly. Secure the caliper with wire or a bungee cord to prevent strain on the brake hose. Do not let the caliper hang by the hose.
4. 4

   Separate CV axle from hub assembly - driver side
   Unbolt the unit bearing hub assembly from the steering knuckle. Remove the hub assembly to expose the axle shaft. Slide the axle shaft out of the axle tube; the inner end is retained at the differential.
5. 5

   Remove driver side CV axle from differential
   Position a drain pan under the differential. Slide the driver side axle shaft out of the axle tube; the inner shaft is retained by a circlip engaging the differential side gear. Apply steady pull and the axle will disengage. Some differential fluid may drain from the tube. Remove the shaft completely from the vehicle.
6. 6

   Separate CV axle from hub assembly - passenger side
   Repeat the separation process for the passenger side CV axle. Use the CV axle puller, slide hammer, or brass punch method to press or drive the splined shaft out of the hub bearing assembly. Move the hub assembly outward to create clearance for axle removal.
7. 7

   Remove passenger side CV axle from differential
   With drain pan positioned under the passenger side, pry the passenger CV axle from the differential case using the same technique as the driver side. The inner joint will pop free from the circlip. Allow remaining differential fluid to drain into the pan. Remove the axle completely from the vehicle.
8. 8

   Drain remaining differential fluid
   With both axles removed and most fluid already drained, remove the differential drain plug at the bottom of the front axle housing to drain any remaining fluid. Allow to drain completely. Replace the drain plug gasket with a new copper or aluminum crush washer.
9. 9

   Inspect and clean differential and hub splines
   Inspect the differential side gears and axle openings for damage or excessive wear. Clean the hub bearing splines with a wire brush and shop towels. Inspect hub bearings for roughness or play (replace if necessary before proceeding). Clean the differential housing mounting surfaces.
10. 10

    Install new driver side CV axle into differential
    Ensure the circlip is properly seated on the inner splined stub of the new driver side CV axle. Insert the inner CV joint straight into the differential side gear, applying firm pressure. You should feel and hear the circlip snap into place. Pull back on the axle to verify it is locked in position.
11. 11

    Install driver side CV axle into hub assembly
    Align the outer CV joint splines with the hub bearing and push the axle shaft through the hub. Use a dead blow hammer to tap the end of the shaft if needed to fully seat the splines. Thread the new 36mm axle hub nut onto the shaft by hand and snug slightly (do not torque yet).
12. 12

    Install new passenger side CV axle
    Repeat the installation process for the passenger side CV axle. Insert the inner joint into the differential until the circlip locks in place, then install the outer end through the hub bearing. Thread the new 36mm hub nut onto the shaft and snug by hand.
13. 13

    Refill front differential
    Locate the fill plug on the front differential housing. Remove the fill plug and gasket. Using a fluid pump or squeeze bottle, add 75W-90 synthetic gear oil (approximately 1.5 quarts / 3.0 pints for the AAM 9.25 front axle — verify capacity in factory service data) through the fill hole until fluid reaches the bottom of the fill plug opening. Install a new fill plug gasket and reinstall the fill plug.
14. 14

    Reconnect tie rod and brake components
    If the tie rod end was disconnected, reconnect it to the steering knuckle and install the castle nut. Torque to specification and install a new cotter pin. If brake calipers were removed, reinstall them with mounting bolts properly torqued. Pump the brake pedal if calipers were disturbed.
15. 15

    Reinstall wheels and torque axle hub nuts
    Reinstall both front wheels and thread lug nuts by hand. Lower the vehicle until the tires just touch the ground with most weight still on jack stands. Torque the axle shaft nut and unit bearing hub retaining bolts to manufacturer specification (verify exact values in factory service data for the AAM front axle). Fully lower the vehicle and torque wheel lug nuts in a star pattern to specification (typically 135 ft-lbs for Ram 3500).

Reassembly

1. Ensure both CV axle circlips are fully engaged in the differential by attempting to pull the axles outward
2. Verify all fasteners are properly torqued including axle hub nuts, wheel lug nuts, and any suspension or steering components that were disconnected
3. Double-check front differential fluid level after vehicle has been lowered and leveled

Verification

• Start the engine and verify no fluid leaks from the front differential drain or fill plugs
• Test drive the vehicle in 4WD mode and verify smooth operation with no clicking, popping, or binding from the CV axles
• Turn the steering wheel full lock in both directions while driving slowly to verify CV joints operate smoothly under load
• Recheck axle hub nut torque and wheel lug nut torque after 50-100 miles of driving
• Inspect for any gear oil leaks around the CV axle seals at the differential after test drive

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