This procedure covers the replacement of the ring and pinion gear set in the rear differential of a 2011-2014 Ford F-150 4WD with 3.5L EcoBoost engine, including differential disassembly, bearing preload setup, and gear pattern verification.

Warnings

Tools required

Parts

• Ring and pinion gear set (verify correct ratio) × 1 — Use OEM specification or quality aftermarket
• Pinion bearing kit (inner and outer bearings with races) × 1 — Use OEM specification
• Carrier bearing set (left and right) × 1 — Use OEM specification
• Pinion seal × 1 — Use OEM specification
• Differential cover gasket or RTV silicone × 1 — Use OEM specification
• Ring gear bolts × 10 — Use new OEM bolts
• Pinion nut × 1 — Use new OEM nut
• Marking compound for gear pattern check × 1 — Dykem or equivalent
• Crush sleeve or solid spacer (depending on application) × 1 — Use OEM specification

Fluids

• Motorcraft 75W-140 Synthetic Gear Oil — 2.5 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Loosen rear wheel lug nuts while vehicle is on ground
3. Raise rear of vehicle and support on jack stands at frame rails
4. Remove rear wheels
5. Place drain pan under rear differential
6. Mark driveshaft and pinion flange orientation for reassembly
7. Take photos of component orientation before disassembly
8. Clean exterior of differential housing with degreaser and wire brush
9. Ensure work area is clean to prevent contamination during assembly

Procedure

1. 1

   Remove driveshaft and drain differential
   Remove the four driveshaft U-joint strap bolts at the pinion flange. Support driveshaft and slide it rearward out of the way. Secure it with wire or mechanic's wire to the frame. Remove differential cover bolts and carefully pry cover off. Allow gear oil to drain completely into drain pan. Clean all gasket material from cover and housing mating surfaces.
   Torque spec

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

   Differential Cover Bolts35 Nm (26 lb-ft)
2. 2

   Mark and measure original setup
   Using an inch-pound torque wrench on the pinion nut, measure and record the pinion bearing preload (rotational torque to turn pinion). Typical specification is 15-25 inch-pounds for used bearings. Install dial indicator on housing and measure ring gear backlash at multiple teeth around the ring gear. Record these measurements - they indicate the original setup and will guide your new installation. Use paint or marker to indicate carrier bearing cap orientation.
3. 3

   Remove carrier assembly
   Remove carrier bearing cap bolts. Note that caps are marked for orientation (left/right). Using a pry bar, carefully work the carrier assembly loose from the housing. The carrier bearings are press-fit, so it may require moderate force. Remove carrier assembly from housing and place on clean workbench. Remove ring gear bolts and separate ring gear from carrier using soft-faced hammer if necessary.
4. 4

   Remove pinion assembly
   Using pinion holding tool to prevent rotation, remove pinion nut with impact wrench or breaker bar. Remove pinion flange using appropriate puller. Carefully drive or press pinion shaft out from front of housing. The pinion will bring the inner bearing, crush sleeve (or shim pack), and any shims with it. Catch all components and keep organized. Remove pinion seal from housing. Use brass drift to carefully drive out outer and inner pinion bearing races from housing. Remove carrier bearings from carrier using bearing puller.
5. 5

   Clean and inspect housing
   Thoroughly clean differential housing interior with solvent and clean rags. Inspect housing for cracks, damage, or excessive wear. Clean all bearing bores and seal surfaces. Inspect housing bearing bores for any damage or excessive wear. Ensure all old gasket material is removed from cover mounting surface. Clean carrier and inspect spider gears and thrust washers for wear. Replace if necessary.
6. 6

   Install new pinion bearing races
   Using bearing race driver set and hammer or hydraulic press, install new outer pinion bearing race into housing bore. Ensure race is seated fully and squarely. Install new inner pinion bearing race into housing bore in same manner. Verify both races are fully seated with no gaps. Apply thin coat of gear oil to race surfaces.
7. 7

   Determine pinion depth
   Use pinion depth setting gauge tool to determine correct shim thickness for new pinion gear. Install gauge tool in housing with appropriate adapters. Measure variance from nominal using dial indicator. New pinion gear will have variance number etched on it (e.g., +2 or -3). Calculate required shim thickness using gauge reading and pinion variance marking. Select appropriate shim(s) from pinion shim kit. This is critical for correct gear pattern.
   ⚠Pinion depth is the most critical measurement in ring and pinion setup. Take multiple measurements to ensure accuracy.
8. 8

   Assemble and install pinion
   Install selected pinion depth shim on pinion shaft. Press inner pinion bearing onto pinion shaft using hydraulic press. Install new crush sleeve (or solid spacer with shim pack) onto pinion shaft. Lubricate inner bearing with gear oil. Carefully insert pinion assembly into housing from front, seating inner bearing into race. Install outer pinion bearing onto pinion shaft (do not press, it will be drawn on by the nut). Install new pinion seal using seal driver, ensuring it seats evenly. Install pinion flange and new pinion nut.
9. 9

   Set pinion bearing preload
   Using pinion holding tool and torque wrench, tighten pinion nut gradually in small increments. Frequently check rotational torque with inch-pound torque wrench. Target preload is 15-25 inch-pounds for new bearings. Once crush sleeve begins to compress, tighten nut in very small increments (1/8 turn or less) and check preload after each increment. Stop immediately when reaching specified preload range. DO NOT overtighten - if you exceed preload specification, you must start over with all new components.
   ⚠️Once pinion nut is tightened and crush sleeve compressed, it cannot be loosened and re-used. Exceeding preload requires replacement of crush sleeve, bearings, and starting over.
10. 10

    Install ring gear on carrier
    Clean ring gear and carrier mounting surfaces thoroughly. Align ring gear on carrier, ensuring proper orientation. Apply thread locking compound to new ring gear bolts. Install ring gear bolts and tighten in star pattern gradually to ensure even seating. Follow torque specifications for ring gear bolts (typically 80-100 lb-ft, but verify for your specific application). Press new carrier bearings onto carrier using hydraulic press or appropriate bearing installation tool. Ensure bearings are fully seated against shoulders.
11. 11

    Install carrier and set backlash
    Install carrier bearing shims on both sides of carrier (start with shims that match original thickness measured during disassembly). Carefully install carrier assembly into housing, seating bearings into races. Install bearing caps in correct orientation (marked during disassembly). Hand-tighten cap bolts. Using dial indicator, measure ring gear backlash at multiple points around ring gear. Target backlash is typically 0.005-0.008 inches. Adjust by moving shims from one side to the other - moving shim from right to left increases backlash, left to right decreases it. Maintain total shim thickness to preserve bearing preload. When backlash is correct, torque bearing cap bolts to specification.
12. 12

    Check gear pattern
    Apply gear marking compound to 3-4 teeth on ring gear in multiple locations around gear. Rotate pinion in both directions under light resistance (use shop towel on flange for drag). Examine contact pattern on ring gear teeth. Pattern should be centered on tooth face for both drive and coast sides. If pattern is incorrect, adjust pinion depth (requires disassembly) or backlash as needed. Drive side pattern toward toe indicates pinion too deep or backlash too tight. Coast side pattern toward toe indicates pinion too shallow or backlash too loose. Repeat adjustment and pattern check until correct pattern is achieved.
    ℹ️Proper gear pattern is essential for gear life. Pattern should be centered lengthwise on tooth and slightly toward toe end. Research correct pattern images before proceeding.
13. 13

    Final bearing preload check
    With carrier installed and bearing caps torqued, check total rotating torque (pinion preload plus carrier bearing drag). Use inch-pound torque wrench on pinion nut and measure torque required to rotate pinion. Total should be pinion preload (15-25 inch-pounds) plus carrier bearing drag (typically 5-10 inch-pounds additional). If total is too low, bearings are loose and require additional shim thickness. Remove carrier and add equal shims to both sides to increase bearing preload without changing backlash.
14. 14

    Install differential cover and fill
    Clean differential cover and housing mating surfaces thoroughly. Apply continuous bead of RTV silicone to cover (or install new gasket per manufacturer instructions). Install cover and cover bolts. Tighten bolts in star pattern to prevent warping cover. Torque cover bolts to specification. Allow RTV to cure per manufacturer instructions (typically 1 hour minimum before filling). Remove fill plug from differential housing. Using fluid pump, fill differential with Motorcraft 75W-140 Synthetic Gear Oil until it reaches bottom of fill hole (approximately 2 quarts). Install fill plug and tighten.
    Torque spec

    Differential Cover Bolts35 Nm (26 lb-ft)
15. 15

    Reinstall driveshaft and wheels
    Align driveshaft with pinion flange using marks made during disassembly. Install U-joint strap bolts and tighten evenly in cross pattern to specification. Install rear wheels and hand-tighten lug nuts. Lower vehicle to ground and torque wheel lug nuts in star pattern to specification.
    Torque spec

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

    Wheel Lug Nuts140 Nm (103 lb-ft)

Reassembly

1. Verify all fasteners are torqued to specification
2. Ensure differential is filled to proper level with correct gear oil
3. Check for any fluid leaks around cover and pinion seal
4. Verify driveshaft is properly aligned and secured

Verification

• Start engine and shift through all gears to verify proper operation
• Test drive vehicle at low speed (under 20 mph) and listen for abnormal noise from differential
• Check for smooth engagement and no vibration during acceleration and deceleration
• After initial 50-mile break-in period, re-check differential fluid level and inspect for leaks
• Monitor differential for unusual noise or temperature during first 500 miles - some gear noise is normal during break-in but should diminish
• After 500 miles, consider changing differential fluid to remove any break-in debris

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