Motor Mount - Electric

This procedure covers the removal and replacement of the electric motor mount on a 2023 Chevrolet Bolt EUV electric vehicle, including high-voltage system de-energization and proper motor support.

Warnings

Tools required

Parts

• Electric motor mount assembly × 1 — Use OEM specification
• Motor mount bolts (if corroded) × 4 — M12 x 1.75 x 50mm
• High-voltage connector seals (if damaged) × 1 — Use OEM specification

Preparation

1. Park vehicle on level, solid surface and engage parking brake
2. Place warning cones around work area and post high-voltage work signs
3. Ensure all personnel are clear that high-voltage work is being performed
4. Verify you have completed EV high-voltage safety training
5. Gather all high-voltage safety equipment including insulated gloves and multimeter
6. Allow vehicle to sit for at least 30 minutes if recently driven to allow components to cool

Procedure

1. 1

   De-energize high-voltage system
   Open hood and locate the 12V battery in the front compartment. Disconnect negative terminal first, then positive terminal. Remove the high-voltage battery service disconnect located in the rear cargo area under the load floor. Turn disconnect counterclockwise and remove completely. Wait minimum 5 minutes for high-voltage capacitors to discharge.
   ⚠️The 5-minute waiting period is mandatory and cannot be shortened. Capacitors retain lethal voltage.
2. 2

   Verify zero voltage on high-voltage system
   Put on high-voltage insulated gloves. Using a high-voltage capable multimeter, verify voltage at the high-voltage battery terminals and at the motor controller is 0V DC. Check multiple points. Document voltage readings. Only proceed if all readings are 0V.
   ⚠️If any voltage is detected, stop work immediately and investigate. System may not be properly de-energized.
3. 3

   Raise and support vehicle
   Lift front of vehicle using hydraulic floor jack at designated lift points. Support vehicle with jack stands at manufacturer-specified support points. Ensure vehicle is stable before working underneath. Remove front driver-side wheel to improve access.
   ⚠Shake vehicle to verify stability before getting underneath.
4. 4

   Remove underbody covers
   Remove front underbody aerodynamic cover by removing all cover screws. Remove driver-side wheel well liner fasteners to access motor mount area. Set covers aside in clean area for reinstallation.
   Torque spec

   Cover Screws11 Nm (8 lb-ft)
5. 5

   Disconnect motor electrical connections
   Wearing high-voltage gloves, disconnect the high-voltage phase connectors from the motor. Remove high-voltage connector bolts and carefully separate connectors. Secure connectors away from work area. Disconnect low-voltage sensor connectors from motor temperature and position sensors.
   ⚠Keep high-voltage connectors clean and dry. Do not allow them to contact vehicle body or ground.
   Torque spec

   Connector Bolts7 Nm (5 lb-ft)

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

   Support electric motor assembly
   Position transmission jack or engine support fixture under the electric motor assembly. Adjust to just contact motor housing without lifting. Ensure support is stable and centered under motor weight. Apply slight upward pressure to unload motor mounts.
   ⚠Motor must be securely supported before removing any mount fasteners to prevent sudden dropping.
7. 7

   Remove motor mount upper bracket
   Locate the motor mount upper bracket that connects to the vehicle body/subframe. Remove bracket bolts securing the upper portion of the mount to the chassis. There are typically 2-3 bolts depending on mount location. Support bracket as you remove final bolt.
   Torque spec

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

   Remove motor mount-to-motor fasteners
   Locate the motor mount bolts that secure the mount to the electric motor housing. These are the primary load-bearing fasteners. Apply penetrating oil if fasteners show corrosion. Remove all motor mount bolts while maintaining motor support with jack. There are typically 4 bolts per mount.
   ⚠These are critical torque fasteners. Inspect threads for damage during removal.
   Torque spec

   Motor Mount Bolts75 Nm (55 lb-ft)
9. 9

   Remove motor mount assembly
   With all fasteners removed and motor properly supported, carefully lower motor slightly on support jack to create clearance. Remove motor mount assembly from between motor and chassis. Inspect mount for cracks, tears in rubber isolator, or fluid leaking from hydraulic mounts. Compare old mount to new mount to verify correct replacement part.
   ℹ️Lower motor no more than 2 inches to avoid stressing drive axles or remaining mounts.
10. 10

    Clean mounting surfaces
    Use wire brush to clean all mounting surfaces on motor housing and chassis bracket. Remove any corrosion, old thread locker, or debris. Inspect bolt threads in motor housing for damage. Chase threads with tap if necessary. Ensure surfaces are clean and dry for proper new mount installation.
11. 11

    Install new motor mount
    Position new motor mount assembly between motor and chassis. Align mount with motor housing and chassis bracket. Raise motor slightly with support jack to align mounting holes. Start all motor mount bolts by hand to ensure proper alignment before tightening any fasteners.
    ℹ️Do not force fasteners. If bolts don't thread easily, reposition motor with support jack.
12. 12

    Torque motor mount fasteners
    Tighten motor mount bolts to motor housing to 75 Nm (55 lb-ft) in a cross-pattern sequence. Install and tighten bracket bolts connecting mount to chassis to 20 Nm (15 lb-ft). Verify all fasteners are properly seated and torqued. Remove support jack slowly while observing mount alignment.
    ⚠Proper torque is critical for mount performance and safety. Use calibrated torque wrench.
    Torque spec

    Motor Mount Bolts75 Nm (55 lb-ft)

    Bracket Bolts20 Nm (15 lb-ft)
13. 13

    Reconnect electrical connections
    Wearing high-voltage gloves, reconnect motor temperature and position sensors. Torque sensor bolts to 11 Nm (8 lb-ft). Reconnect high-voltage phase connectors to motor, ensuring proper alignment and seating. Install high-voltage connector bolts and torque to 10 Nm (7 lb-ft). Install connector bolts to 7 Nm (5 lb-ft) for low-voltage connections.
    ⚠High-voltage connectors must be fully seated with no gaps before installing bolts.
    Torque spec

    Sensor Bolts11 Nm (8 lb-ft)

    Connector Bolts7 Nm (5 lb-ft)
14. 14

    Reinstall underbody covers and wheel
    Reinstall driver-side wheel well liner with all fasteners. Install front underbody aerodynamic cover and torque all cover screws to 11 Nm (8 lb-ft). Reinstall front wheel and torque lug nuts to manufacturer specification (140 Nm / 103 lb-ft typical). Lower vehicle from jack stands.
    Torque spec

    Cover Screws11 Nm (8 lb-ft)
15. 15

    Re-energize high-voltage system
    Reinstall high-voltage battery service disconnect in rear cargo area, turning clockwise until fully seated. Reconnect 12V battery terminals (positive first, then negative). Clear any diagnostic trouble codes using scan tool. Verify READY light illuminates when power button is pressed.

Reassembly

1. Torque all fasteners to specified values using calibrated torque wrench
2. Verify all high-voltage connections are fully seated and properly torqued
3. Ensure all underbody covers are reinstalled to maintain aerodynamics
4. Double-check that all electrical connectors are locked in place

Verification

• Start vehicle and verify READY light illuminates with no warning lights
• Check for abnormal vibration at idle and during initial acceleration
• Perform test drive and verify no unusual noises from motor mount area
• Monitor for diagnostic trouble codes related to motor sensors or high-voltage system
• Visually inspect motor mount area for proper alignment and no interference
• Verify no high-voltage insulation warnings appear on instrument cluster

Related trouble codes on this vehicle

Codes that commonly send this job to the bay — tap one for symptoms, causes, and diagnostic steps.

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