Axle Shaft - Rear

This procedure covers the removal and replacement of the rear axle shaft on a 2007 Ram 3500 with the AAM 11.5" rear differential, including bearing and seal service.

Warnings

Tools required

Parts

• Rear axle shaft (left or right as needed) × 1 — Use OEM specification
• Axle shaft bearing × 1 — Use OEM specification
• Axle shaft seal × 1 — Use OEM specification
• Differential cover gasket × 1 — Use OEM specification
• RTV silicone sealant (if reusing cover) × 1 — Mopar or equivalent
• Brake parts cleaner × 1 — Aerosol can

Fluids

• 75W-90 synthetic gear oil — 5.5 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Place wheel chocks in front of front wheels
3. Loosen rear wheel lug nuts while vehicle is on ground (dually models have inner and outer wheels)
4. Raise rear of vehicle and support securely with jack stands under frame rails
5. Remove rear wheels completely (both inner and outer on dually models)
6. Position drain pan under differential cover

Procedure

1. 1

   Drain differential fluid
   Remove all differential cover bolts using appropriate socket. Carefully pry cover loose at bottom edge and allow fluid to drain completely into drain pan. Once drained, remove cover fully and set aside. Remove old gasket material from housing and cover surfaces using a scraper and wire brush. Clean surfaces thoroughly with brake cleaner. The AAM 11.5" from the factory uses RTV silicone rather than a molded gasket. Differential cover sealant (RTV) or reusable cover gasket as applicable.
2. 2

   Remove axle shaft retaining hardware
   Locate the eight bolts securing the axle shaft flange to the hub assembly on the side being serviced. These bolts are accessible from the backside of the brake assembly. Use a socket and breaker bar to remove all eight bolts. Keep bolts organized for reinstallation.
3. 3

   Extract axle shaft from housing
   Pull the axle shaft straight out from the axle housing. On the AAM 11.5" full-floating axle, the shaft is retained only by the flange bolts and should pull straight out by hand once they are removed. If the shaft is stuck due to a stuck flange gasket or corrosion, tap the flange or use a slide hammer attached to the flange bolt holes to free it. Do not pry or hammer on brake components. Withdraw shaft completely and set aside.
4. 4

   Inspect differential and axle tube
   With axle shaft removed, visually inspect the differential internals for any metal shavings, damaged gears, or excessive wear. Check the axle tube bore for scoring or damage. Inspect the removed axle shaft splines for wear, twisting, or cracks. Replace shaft if any damage is found.
5. 5

   Remove axle shaft bearing and seal
   NOTE: The AAM 11.5" is a full-floating axle. The wheel bearings are tapered roller bearings that ride on the spindle and are serviced with the hub, not pressed into the axle tube. There is no axle-shaft bearing pressed into the tube on this axle. If hub bearing or seal service is required, remove the hub/spindle nut assembly and service the hub bearings and hub seal per the factory service manual. Take care not to damage the seal bore surface in the axle tube.
6. 6

   Clean and prepare axle tube
   Thoroughly clean the bearing and seal bore areas inside the axle tube using brake cleaner and shop rags. Remove any dirt, old grease, or debris. Inspect the bore surfaces for damage or scoring. Light surface rust can be cleaned with fine emery cloth, but deep scoring requires axle housing replacement.
7. 7

   Install new axle shaft bearing
   NOTE: This axle does not use a bearing pressed into the axle tube. If hub bearing service is required, install the tapered roller bearings and races into the hub, pack them with wheel bearing grease, and set preload per the factory service manual specification. Ensure bearing is fully seated and not cocked in the bore. The bearing should be approximately flush with or slightly recessed from the tube end.
8. 8

   Install new axle shaft seal
   Apply a thin coat of gear oil to the outer diameter of the new seal and the seal bore. If servicing the hub seal, install the new seal into the hub bore using a seal driver of appropriate diameter until it seats flush, with the seal lip facing inward. Install a new axle flange gasket or apply RTV to the axle shaft flange on reassembly. Ensure seal is installed squarely and not damaged during installation.
9. 9

   Install axle shaft
   Lightly coat the axle shaft splines with gear oil. Carefully insert the axle shaft into the axle tube, ensuring the splines align with the differential side gear. Slide the shaft in slowly to avoid damaging the new seal. Install a new axle flange gasket (or apply a thin bead of RTV) to the axle shaft flange. Push shaft in until the flange seats against the hub mounting surface. Ensure shaft is fully engaged with the differential side gear splines.
10. 10

    Secure axle shaft to hub
    Install all eight axle flange bolts through the hub and thread into the axle shaft flange. Start all bolts by hand before tightening. Tighten bolts in a star pattern to ensure even seating. Since factory torque specifications are not available in the database, tighten bolts firmly and evenly. Factory specification for the AAM 11.5" axle flange bolts is approximately 115 ft-lbs; verify with a factory service manual before final tightening.
    ℹ️Consult factory service manual for exact torque specification as none is provided in this database.
11. 11

    Install differential cover
    If reusing the original cover, clean it thoroughly and apply a 1/8" bead of RTV silicone sealant to the cover flange. If using a new gasket, position it on the differential housing. Install the cover and thread in all cover bolts finger-tight. Tighten bolts in a criss-cross pattern gradually to compress gasket or RTV evenly. Typical cover bolt torque is approximately 30 ft-lbs, but verify with service manual. If using RTV, allow 1 hour cure time before filling.
12. 12

    Refill differential with gear oil
    With vehicle level, remove the differential fill plug (located on the differential cover). Using a fluid pump or squeeze bottle, fill the differential with 75W-90 synthetic gear oil until fluid begins to drip from the fill hole. The AAM 11.5" differential requires approximately 3.5 quarts; verify capacity and friction modifier requirement with the factory service manual. Install and tighten the fill plug once proper level is achieved.

Reassembly

1. Reinstall inner and outer rear wheels (dually models) and hand-tighten lug nuts
2. Lower vehicle until wheels just contact ground but suspension is not loaded
3. Torque wheel lug nuts to specification in a star pattern (consult owner's manual for exact specification, typically 135-145 ft-lbs for 3500 series)
4. Fully lower vehicle to ground and remove jack stands
5. Remove wheel chocks

Verification

• Start vehicle and verify no differential leaks around cover, fill plug, or axle seals
• Test drive vehicle at low speed in a safe area, making several turns in both directions
• Listen for any abnormal noises from the rear axle during acceleration and deceleration
• After test drive, re-inspect all work areas for fluid leaks
• Check differential fluid level after 50-100 miles and top off if necessary
• Verify proper brake function if brake components were disturbed during axle removal

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