Electric Drive Motor R&R

Complete removal and replacement of the electric drive motor assembly on the 2023 Chevrolet Bolt EUV, including high-voltage system de-energization, drive unit disconnection, and motor extraction.

Warnings

Tools required

Parts

• Electric drive motor assembly × 1 — Use OEM specification
• Drive unit gasket/seal kit × 1 — Use OEM specification
• High-voltage connector seals × 1 — Use OEM specification
• Motor mount hardware kit × 1 — Use OEM specification

Fluids

• ACDelco Dexron VI ATF — 13.5 qt

Preparation

1. Ensure vehicle is on level ground and parking brake is engaged
2. Place wheel chocks behind rear wheels
3. Verify high-voltage safety equipment is available and in good condition
4. Disconnect 12V auxiliary battery negative terminal and wait 2 minutes
5. Raise vehicle on lift or jack stands to working height with front wheels off ground
6. Remove front wheels and inner fender splash shields
7. Place warning tags on 12V battery and high-voltage service disconnect indicating service in progress

Procedure

1. 1

   De-energize high-voltage system
   Don high-voltage safety gloves. Open rear cargo area and remove rear cargo floor cover. Locate high-voltage battery service disconnect under rear seat access panel. Rotate service disconnect lever counterclockwise to OFF position and remove service disconnect plug. Store plug away from vehicle. Wait minimum 10 minutes for capacitor discharge.
   ⚠️Do not proceed until 10 minute wait period has elapsed. High-voltage capacitors retain lethal charge.
2. 2

   Verify zero voltage state
   Using calibrated high-voltage multimeter, verify zero voltage at high-voltage bus bars near drive unit. Check voltage between positive and negative terminals, positive to chassis ground, and negative to chassis ground. All readings must be below 3 volts DC before proceeding.
   ⚠️If any voltage above 3V DC is detected, do not proceed. Wait additional time or investigate for system fault.
3. 3

   Drain drive unit fluid
   Position drain pan under drive unit. Remove drive unit drain plug and allow Dexron VI ATF to fully drain. This will take approximately 15-20 minutes for complete drainage. Note fluid condition for contamination. Once drained, reinstall drain plug with new sealing washer.
   Torque spec

   Mounting Bolts27 Nm (20 lb-ft)
4. 4

   Disconnect high-voltage power cables
   Locate high-voltage connector assembly on top of drive motor inverter. Remove protective cover by removing cover screws. Wearing insulated gloves and using insulated tools, remove high-voltage connector bolts securing positive and negative power cables. Carefully separate connectors and secure cables away from work area with non-conductive tie. Install protective caps on cable ends.
   ⚠Handle high-voltage cables carefully. Do not bend or kink cables excessively.
   Torque spec

   Cover Screws11 Nm (8 lb-ft)

   Connector Bolts7 Nm (5 lb-ft)
5. 5

   Disconnect motor resolver and sensors
   Locate motor position resolver connector and temperature sensors on motor housing. Disconnect electrical connectors by releasing locking tabs. Remove sensor bolts securing position resolver to motor housing. Support resolver during removal to prevent cable strain. Remove coolant temperature sensor from motor housing by removing sensor bolts.
   Torque spec

   Sensor Bolts11 Nm (8 lb-ft)
6. 6

   Disconnect cooling system connections
   Locate motor cooling inlet and outlet connections on motor housing. Place drain pan underneath. Release quick-connect fittings for coolant lines by pressing release tabs and pulling lines straight out. Allow residual coolant to drain. Cap open fittings to prevent contamination.
   ⚠Coolant may still be warm. Allow adequate cooling time if vehicle was recently operated.
7. 7

   Disconnect drive axles
   Remove drive axle retaining nuts at both sides. Using appropriate puller tool, separate outer CV joints from wheel hubs. Support drive axles and remove intermediate shaft bracket bolts. Carefully pry drive axles from drive unit output flanges using non-metallic pry bar. Support axles with wire to prevent damage to CV boots.
   Torque spec

   Bracket Bolts20 Nm (15 lb-ft)
8. 8

   Remove motor support brackets
   Locate and remove motor support brackets connecting drive unit to subframe and chassis. Remove bracket bolts from each mounting location. There are typically 4-6 brackets depending on configuration. Keep hardware organized by location for reinstallation.
   Torque spec

   Bracket Bolts20 Nm (15 lb-ft)
9. 9

   Support drive motor assembly
   Position engine hoist with appropriate lifting fixture under drive motor assembly. Attach lifting fixture to designated lift points on motor housing. Apply slight upward pressure to support motor weight before removing mounts. Verify lift is secure and balanced.
   ⚠Ensure lifting fixture is rated for minimum 250 lbs and properly attached before removing mount bolts.
10. 10

    Remove motor mount bolts
    With motor weight supported by hoist, remove motor mount bolts securing drive unit to subframe at all mounting locations. There are typically 4 primary motor mount bolts. Remove bolts in diagonal pattern to maintain balanced support. Keep mount hardware separated for inspection.
    Torque spec

    Motor Mount Bolts75 Nm (55 lb-ft)
11. 11

    Extract drive motor assembly
    With all connections and mounts removed, carefully lower drive motor assembly using engine hoist. Guide motor assembly forward and down while clearing subframe and surrounding components. Have second technician guide motor to prevent contact with body or chassis. Once clear, lower motor onto suitable work surface or motor stand.
    ⚠Motor assembly is heavy and awkward. Move slowly and maintain control throughout extraction.
12. 12

    Inspect mounting points and sealing surfaces
    With motor removed, inspect all mounting points on subframe for damage, cracks, or wear. Clean mounting surfaces with wire brush. Inspect drive unit output shaft seals and replace if any fluid leakage is evident. Check drive axle splines for damage. Clean all mating surfaces where motor will reinstall.
    ℹ️This is ideal time to inspect and replace drive axle boots or seals if needed.
13. 13

    Install replacement drive motor
    Mount replacement motor on hoist with lifting fixture. Apply thin film of clean Dexron VI to output shaft seals. Guide motor into position, aligning with subframe mounting points. Have second technician guide motor while operator controls hoist. Align motor carefully to avoid damage to seals or mounting points.
    ⚠Ensure all electrical connectors and coolant fittings are clear during installation.
14. 14

    Install motor mount bolts
    With motor positioned correctly, install motor mount bolts through mounting brackets into subframe. Start all bolts by hand before tightening. Tighten motor mount bolts in diagonal pattern to specified torque of 75 Nm (55 lb-ft). Verify motor is properly seated before removing hoist support.
    Torque spec

    Motor Mount Bolts75 Nm (55 lb-ft)
15. 15

    Reconnect drive axles and brackets
    Install drive axles into motor output flanges ensuring splines are fully engaged. Install intermediate shaft bracket bolts to specified torque. Connect outer CV joints to wheel hubs and install new axle nuts (torque per separate specification). Reinstall all support brackets removed earlier.
    Torque spec

    Bracket Bolts20 Nm (15 lb-ft)
16. 16

    Reconnect cooling and sensor connections
    Remove protective caps from coolant fittings. Reconnect coolant inlet and outlet lines to motor, ensuring quick-connect fittings fully seat with audible click. Install motor position resolver and tighten sensor bolts to specified torque. Install temperature sensor with new seal and tighten sensor bolts. Reconnect all electrical connectors ensuring positive lock engagement.
    Torque spec

    Sensor Bolts11 Nm (8 lb-ft)
17. 17

    Reconnect high-voltage power cables
    Remove protective caps from high-voltage cable ends. Wearing high-voltage gloves and using insulated tools, carefully position high-voltage connectors onto motor inverter terminals. Install high-voltage connector bolts and tighten to specified torque of 10 Nm (7 lb-ft). Verify connections are secure. Install protective cover and tighten cover screws.
    ⚠Do not over-torque high-voltage connector bolts as this may damage terminals.
    Torque spec

    Connector Bolts7 Nm (5 lb-ft)

    Cover Screws11 Nm (8 lb-ft)
18. 18

    Fill drive unit with transmission fluid
    Using transmission fluid pump, add ACDelco Dexron VI ATF through fill port until fluid reaches proper level per service manual specification (approximately 13.5 quarts total capacity). Allow fluid to settle and verify level is correct. Install fill plug with new sealing washer.
    Torque spec

    Mounting Bolts27 Nm (20 lb-ft)
19. 19

    Reinstall underbody components
    Reinstall inner fender splash shields and any other underbody panels removed for access. Install front wheels and torque lug nuts per specification. Lower vehicle to ground.
20. 20

    Re-energize high-voltage system
    Reconnect 12V auxiliary battery negative terminal. Access high-voltage service disconnect in rear cargo area. Install service disconnect plug and rotate lever clockwise to ON position. Remove warning tags. Close all access panels and cargo floor.
    ℹ️High-voltage system is now energized. Observe all high-voltage safety protocols.

Reassembly

1. Torque all fasteners to specified values in proper sequence
2. Use new seals and gaskets during reassembly
3. Verify all electrical connectors are fully seated and locked
4. Ensure high-voltage protective covers are properly installed
5. Double-check that no tools or hardware are left in vehicle

Verification

• Perform visual inspection of all connections and verify no fluid leaks
• Using scan tool, clear any DTCs and verify no high-voltage system faults present
• Perform propulsion system test: key on and verify READY indicator illuminates
• Test drive vehicle in controlled area to verify normal operation, smooth acceleration, and no abnormal noises
• Monitor drive motor temperature during test drive to ensure proper cooling system function
• Verify transmission fluid level after test drive and top off if necessary
• Perform final high-voltage system integrity test with scan tool
• Verify all warning lamps extinguish and vehicle operates normally

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