Complete disassembly, inspection, and rebuild of the front differential assembly including carrier bearings, pinion bearings, ring and pinion gears, and seals on the 2014 Ram 2500 with AAM 9.25 front axle.

Warnings

Tools required

Parts

• Front differential master overhaul kit × 1 — AAM 9.25 master bearing kit
• Ring and pinion gear set × 1 — Verify gear ratio from door sticker
• Pinion seal × 1 — Included in master kit
• Pinion nut × 1 — Use new nut
• Axle shaft seals × 2 — RH and LH
• Drain plug washer × 1 — Copper or aluminum crush washer
• Fill plug washer × 1 — Copper or aluminum crush washer
• Differential cover gasket or RTV × 1 — Mopar RTV sealant preferred
• Cotter pin for axle nut × 2 — Use appropriate size new pin

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 front wheel lug nuts while vehicle is on ground
4. Raise front of vehicle and support on jack stands at frame rails
5. Remove both front wheels
6. Place drain pan under front differential
7. Mark driveshaft and pinion flange orientation for reassembly
8. Take photos of component positions before disassembly for reference

Procedure

1. 1

   Drain differential and remove driveshaft
   Remove drain plug with new washer ready for reinstallation. Drain all gear oil into catch pan. Remove driveshaft U-joint strap bolts at front pinion flange and carefully lower driveshaft. Support driveshaft or remove completely. Plug or cap transfer case output to prevent fluid loss.
   Torque spec

   Drain Plug55 Nm (41 lb-ft)

   Driveshaft U-Joint Straps20 Nm (15 lb-ft)
2. 2

   Remove axle shafts
   Remove CV axle shaft bolts at both sides connecting inner CV joints to differential flanges. Remove cotter pins and axle nuts from wheel hubs. Carefully pull axle shafts from differential and hubs, supporting CV joints. Mark left and right for reinstallation. Plug differential side openings with rags to prevent debris entry.
   Torque spec

   CV Bolts82 Nm (61 lb-ft)

   Axle Nut250 Nm (184 lb-ft)
3. 3

   Remove differential cover and carrier
   Remove all differential cover bolts and carefully pry cover off. Clean mating surface thoroughly. Mark bearing cap positions and orientation with paint or punch marks. Remove bearing cap bolts and caps. Install case spreader tool on carrier housing and spread case slightly (no more than 0.015 inch). Carefully pry carrier assembly out of housing with bearing races. Remove carrier to workbench.
   Torque spec

   Cover Bolts46 Nm (34 lb-ft)
4. 4

   Measure and record pinion depth and backlash
   Before disassembly, install dial indicator on carrier and measure ring gear backlash at 4 points around the gear (should be 0.005-0.009 inch typically). Record pinion depth shim thickness if visible. Note gear tooth contact pattern by coating teeth with marking compound and rotating under load. Take detailed notes and photos of all measurements for reference during reassembly.
5. 5

   Remove ring gear from carrier
   Mark ring gear to carrier orientation. Remove all ring gear bolts (typically 10-12 bolts). Tap ring gear off carrier using soft-face hammer. If stuck, use brass drift evenly around gear. Do not pry between gear and carrier. Inspect carrier for cracks or damage. Clean carrier thoroughly.
6. 6

   Disassemble and measure pinion
   Hold pinion flange with appropriate tool and remove pinion nut (record torque required to rotate pinion for bearing preload reference). Use appropriate puller to remove flange. Carefully tap pinion out of housing from front. Catch pinion and bearings. Remove and record all shim thicknesses. Press bearings off pinion using bearing separator. Measure and record pinion head thickness with micrometer. Inspect pinion for wear or damage.
7. 7

   Remove carrier bearings and inspect components
   Using bearing puller or press, remove carrier bearings from carrier assembly. Keep shims with their respective bearings and record thicknesses. Inspect all bearing races and rollers for pitting, scoring, or wear. Inspect ring and pinion gear teeth for excessive wear, scoring, or damage. Check carrier for cracks. Clean all parts thoroughly with solvent and air dry.
8. 8

   Install new pinion bearings and determine depth
   Press new inner and outer pinion bearings onto new pinion using press and appropriate drivers. Install pinion depth gauge tool according to manufacturer instructions. Measure pinion depth and calculate correct shim thickness based on pinion head marking and gauge reading. Install calculated depth shim on pinion. Lubricate bearings with gear oil.
9. 9

   Install pinion assembly with preload
   Install new pinion seal in housing using seal driver. Install pinion with bearings into housing. Install collapsible spacer (new), outer bearing race, and companion flange. Install new pinion nut and tighten gradually while measuring rotational torque with inch-pound torque wrench. Target preload is typically 15-25 inch-pounds for new bearings. Do not overtighten or you must replace collapsible spacer. Once proper preload is achieved, do not back off nut.
10. 10

    Install ring gear on carrier
    Heat ring gear in hot water or oven to approximately 200°F for thermal expansion. Align marks on ring gear and carrier. Install ring gear onto carrier, ensuring proper seating. Install all ring gear bolts with medium-strength thread locker. Tighten bolts in star pattern to specifications (typically 90-100 ft-lbs, verify with service manual). Allow assembly to cool completely.
11. 11

    Install carrier bearings and set backlash
    Press new carrier bearings onto carrier assembly. Install bearing shims starting with recorded original thickness. Install carrier assembly into housing using case spreader. Install bearing caps in correct orientation with marks aligned. Tighten bearing cap bolts to specification. Measure ring gear backlash with dial indicator. Adjust by moving shims from one side to other until backlash is 0.005-0.009 inch. Ensure proper pinion-to-ring gear contact pattern.
12. 12

    Check gear tooth contact pattern
    Apply thin coat of gear marking compound to 6-8 teeth on ring gear. Rotate pinion in both directions under light resistance. Check contact pattern on drive and coast sides. Pattern should be centered on tooth face, slightly toward toe. Adjust pinion depth shim if pattern is too high or low. Adjust backlash if pattern is too far toward toe or heel. Repeat until proper pattern is achieved.
13. 13

    Install differential cover
    Clean housing and cover mating surfaces thoroughly with solvent. Remove all old gasket material and RTV. Apply continuous bead of RTV silicone sealant (approximately 1/8 inch bead) around cover mating surface. Install cover immediately while RTV is wet. Install all cover bolts and tighten in star pattern to specification. Allow RTV to cure for at least 1 hour before filling with oil.
    Torque spec

    Cover Bolts46 Nm (34 lb-ft)
14. 14

    Reinstall axle shafts and driveshaft
    Install new axle shaft seals in differential housing using seal driver. Clean axle shaft splines and CV joint mating surfaces. Carefully install axle shafts into differential and through hubs, ensuring proper engagement. Install CV bolts at differential flanges and tighten to specification. Install axle nuts finger-tight. Align driveshaft marks and install driveshaft to pinion flange. Install U-joint strap bolts and tighten evenly to specification.
    Torque spec

    CV Bolts82 Nm (61 lb-ft)

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

    Fill differential and perform final torque
    Remove fill plug with new washer ready. Using gear oil pump, fill differential with 75W-90 GL-5 gear oil until level reaches bottom of fill hole (approximately 1.5 quarts). Install fill plug with new washer and torque to specification. Install drain plug with new washer to specification. Torque axle nuts to specification and install new cotter pins. Install wheels and torque lug nuts in star pattern to specification. Lower vehicle.
    Torque spec

    Fill Plug55 Nm (41 lb-ft)

    Drain Plug55 Nm (41 lb-ft)

    Axle Nut250 Nm (184 lb-ft)

    Wheel Lug Nuts140 Nm (103 lb-ft)

Reassembly

1. Ensure all bearing preload and backlash measurements are within specification before final assembly
2. Apply thread locker to all fasteners as specified
3. Use only new crush washers, cotter pins, and collapsible spacer - never reuse these components
4. Allow RTV sealant to cure fully before filling with gear oil
5. Double-check all torque specifications after initial tightening

Verification

• Check for gear oil leaks around cover, pinion seal, and axle seals after first drive
• Test drive vehicle and listen for abnormal differential noise (whining, howling, or clunking)
• Verify smooth operation through turns in both directions in 4WD mode
• Recheck differential fluid level after first 50 miles of driving
• Monitor differential temperature during break-in period - should not be excessively hot
• Inspect gear tooth contact pattern if any noise is present - may require adjustment
• Check all fastener torque after 100 miles of operation

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