Complete disassembly, inspection, and rebuild of the front differential assembly on the Rivian EDV 500, including bearing replacement, seal installation, and gear pattern verification.

Warnings

Tools required

Parts

• Front differential rebuild kit (includes bearings, seals, shims) × 1 — Use OEM specification
• Differential cover gasket or RTV silicone × 1 — Use OEM specification
• Front axle seals (left and right) × 2 — Use OEM specification
• Pinion seal × 1 — Use OEM specification
• Crush sleeve or pinion shim pack × 1 — Use OEM specification
• Ring gear bolts × 1 — Use OEM specification
• Differential case bolts × 1 — Use OEM specification
• Marking compound × 1 — Gear pattern compound

Fluids

• 75W-90 GL-5 Gear Oil — 1.5 qt

Preparation

1. Place vehicle on lift and raise to working height, ensuring proper support on manufacturer-specified lift points
2. Using Rivian diagnostic software, disable high-voltage system and place vehicle in service mode
3. Disconnect 12V battery negative terminal and wait 5 minutes for system capacitors to discharge
4. Remove front wheels and store safely
5. Drain front differential fluid into appropriate container by removing drain plug, allow 15 minutes for complete drainage
6. Disconnect front drive unit electrical connectors and secure away from work area
7. Remove front driveshafts from differential output flanges and support with mechanics wire
8. Support front drive unit assembly with transmission jack before removal

Procedure

1. 1

   Remove front drive unit assembly from vehicle
   Remove all mounting bolts securing the front drive unit to the subframe. Carefully lower the assembly on the transmission jack. Transport to clean workbench for disassembly. Note the position of any wiring harness brackets or ground connections for reinstallation.
2. 2

   Remove differential cover and drain remaining fluid
   With the drive unit on the workbench, remove all differential cover bolts in a crisscross pattern. Carefully separate the cover from the housing using a plastic mallet if needed. Remove and discard the gasket or clean off old RTV. Allow any remaining fluid to drain completely.
3. 3

   Mark and remove differential bearing caps
   Use a center punch or marker to clearly mark the bearing caps and housing for proper reassembly orientation. Remove the bearing cap bolts and carefully remove both bearing caps. Note the position of any shims behind the bearing caps and measure their thickness with a micrometer. Record all measurements.
4. 4

   Remove differential carrier assembly
   Carefully lift the differential carrier assembly with ring gear attached from the housing. If bearing races are tight, use a differential spreader tool to slightly spread the housing (maximum 0.015 inches). Remove side bearings using a bearing puller, keeping left and right bearings separate and labeled.
5. 5

   Disassemble and inspect ring gear
   Remove ring gear bolts (these are typically one-time-use bolts and should be replaced). Separate ring gear from carrier using a soft mallet if needed. Inspect ring gear teeth for wear, pitting, scoring, or cracking. Inspect carrier for cracks or damage. Check spider gear and side gear wear by attempting to rock gears - excessive play indicates replacement needed.
6. 6

   Remove pinion assembly
   Mark pinion flange orientation to pinion shaft. Hold pinion flange and remove pinion nut. Use a flange puller to remove the pinion flange. Tap pinion shaft out of housing from the front, catching bearings and shims. Remove pinion seal from housing using seal puller. Remove and label front and rear pinion bearings and note all shim positions and thicknesses.
7. 7

   Clean and inspect all components
   Thoroughly clean the differential housing, carrier, and all reusable components with solvent. Inspect housing for cracks, especially around bearing bores and bolt holes. Inspect all bearing races in the housing for pitting, scoring, or wear. Check gear teeth on both ring and pinion for wear patterns. Measure all bearing bores and journals for wear using telescoping gauges and micrometers. Replace any worn or damaged components.
8. 8

   Install new pinion bearing races
   Using appropriate bearing race installation drivers, install new inner and outer pinion bearing races in the housing. Ensure races are fully seated and square. Verify seating by measuring depth with a depth micrometer and comparing to specifications. Install rear pinion bearing on pinion shaft using bearing installation tool or press.
9. 9

   Set pinion depth and preload
   Install pinion depth shims as determined by measuring old shim pack or using pinion depth gauge tool. Install pinion assembly into housing with front bearing. Install collapsible spacer or shim pack and new pinion seal using seal driver. Install pinion flange and new pinion nut. Tighten pinion nut incrementally while checking rotating torque with inch-pound torque wrench. Target preload should be 15-25 in-lbs for new bearings. Do not back off nut - if overtightened, replace collapsible spacer and start over.
10. 10

    Install ring gear on carrier
    Clean carrier and ring gear mating surfaces thoroughly. Heat ring gear to 200°F for easier installation if needed. Align ring gear on carrier and install new ring gear bolts with medium-strength thread locker. Tighten bolts in a star pattern incrementally. Ring gear should be fully seated against carrier shoulder with no gaps.
11. 11

    Install side bearings and carrier assembly
    Press new side bearings onto the differential carrier, ensuring they are fully seated. Install original shims as a starting point. Carefully install the carrier assembly into the housing. Install bearing caps in their marked positions and snug cap bolts (do not fully tighten yet).
12. 12

    Set backlash and side bearing preload
    Mount dial indicator to measure ring gear backlash at several teeth locations (90-degree intervals). Adjust backlash to specification (typically 0.005-0.008 inches) by moving shims from one side to the other - moving shims from right to left increases backlash. After achieving correct backlash, add 0.005 inches of shims to each side for bearing preload. Verify backlash remains within specification after preload adjustment.
13. 13

    Check and verify gear contact pattern
    Apply thin coat of gear marking compound to 8-10 ring gear teeth. Rotate pinion through mesh in both directions under light drag. Examine contact pattern on both drive and coast sides. Pattern should be centered on tooth face. Adjust pinion depth shims if pattern is too high or low, or adjust backlash if pattern is too far toward toe or heel. Repeat marking and adjustment until proper pattern is achieved on both sides.
14. 14

    Final torque and seal installation
    Once gear pattern is correct, remove bearing caps and apply medium-strength thread locker to cap bolts. Reinstall caps and torque bolts to specification in a crisscross pattern. Verify backlash has not changed. Install new axle seals using appropriate seal driver, ensuring they are square and seated to proper depth. Apply small amount of gear oil to seal lips.
15. 15

    Install differential cover and fill with fluid
    Clean cover and housing mating surfaces thoroughly. Apply new gasket or RTV silicone bead (1/8 inch) around cover perimeter. Install cover and tighten bolts in crisscross pattern. Install and torque fill plug. Fill differential with 1.5 quarts of 75W-90 GL-5 gear oil through fill hole until oil begins to seep from hole. Install fill plug and torque to specification.

Reassembly

1. Reinstall front drive unit assembly into vehicle using transmission jack, ensuring all mounting bolts are torqued to specification
2. Reconnect all electrical connectors to front drive unit and motor controller
3. Install front driveshafts to differential output flanges with new hardware
4. Reinstall front wheels and torque lug nuts to specification in star pattern
5. Reconnect 12V battery negative terminal
6. Using Rivian diagnostic software, clear any stored fault codes and exit service mode

Verification

• With vehicle still raised, start vehicle and engage drive mode to verify front motor operation without unusual noises
• Check for any fluid leaks around differential cover, pinion seal, and axle seals
• Lower vehicle and perform test drive at various speeds, listening for whine, growl, or clunking noises
• Perform figure-eight maneuvers to verify proper operation under load and turning
• Re-check differential fluid level after test drive and top off if necessary
• Use diagnostic software to verify no fault codes related to front drive unit
• After 100 miles of operation, recheck differential fluid level and inspect for leaks

More procedures for this vehicle