See inside the Bolt EV Motor and Drive Unit

TIMELINE:
0:00 introduction
0:36 Drive Unit (DU) Specifications
0:55 MUST SEE - Motor torque versus torque to the wheels
3:57 Lubrication and coolant
4:27 Drive Unit Identification and Option Codes
5:34 See the Transmission Range Selector Actuator and shifter
6:48 Transmission fluid fill, drain, and fluid level checking
8:52 Transmission electric fluid pump (12V) operation
9:53 Motor resolver and fluid temperature sensor connector
10:52 Rearview and components
11:55 Transmission holding fixture
12:31 Transmission weight
12:40 Electric Gerotor type fluid pump removal
13:39 Removal of the Output Shafts
16:53 Transmission Range Selector Actuator removal
18:03 Transmission Case (Right Side Cover) removal
18:56 Shift linkage, park pawl, and Internal Mode Switch (IMS)
19:42 Ring gear, differential, bearings, and end-play shims
22:32 Non-reusable aluminum gaskets
22:41 Oil baffle and magnet
23:43 Differential case removal
24:44 Transmission Case Cover (Left Side Cover) removal
26:46 Oil filter, Resolver, and fluid temperature sensor
27:18 End view of the motor rotor, stator, and lubrication/cooling channel
28:10 Fluid filter removal and positioning
28:48 Resolver removal
30:05 Bearing center support removal
30:35 Counter drive gear removal
31:09 Lubrication channel and three-phase cable nut retainer removal
31:32 Oil distribution channel removal
31:45 Preparation for rotor removal
32:58 MUST SEE - Rotor centering tool installation
37:14 Oil sump cover removal
38:02 Coolant sump cover removal
39:16 Installation of Rotor puller tools
43:38 MUST SEE - Pulling the Rotor from the Stator
49:04 Rotor components
50:42 Stator removal procedure
51:50 MUST SEE - Stator unique design review
52:01 The "Small Block Chevrolet" of electric motors
54:56 THREE MOVING PARTS and reliability
57:33 Video wrap-up

VIDEO UPDATES:
Bearing Grey Coating Information Update:
Thank you to SeanBZA! "Grey coating is an insulator, to prevent circulating currents through the bearings from any slight imbalance in the magnetic field in the motor. there is a single bearing that is grounded ( the shiny one) to prevent charge build-up on the rotor and a flashover to the frame, but the rest have to be insulated so they do not have a shorted turn through the frame that can cause a high circulating current through the bearings that rapidly erodes them through arcing. There are current paths for this current via things like the output shafts and the selector forks, but they probably assumed that being long thin wall section steel assemblies, this long path would both keep the current low enough not to cause any major extra wear, and also the long output shaft would be mostly self-canceling field wise as well.

A lot of larger electric motors handle this with one end having coated bearings, or they make them with ceramic bearing balls inside, or just make both sides with insulated bearing mounting frames, and provide a grounding carbon brush assembly to handle shaft grounding. A drawback of the coated bearing is that you have to ensure that there is absolutely no damage to the coating on the outside and the side facing the frame so that there is no metal-to-metal path. However, depending on the exact coating applied, this coat can be both insulating and tougher than the steel of the bearing itself. grey would point to a spray-on ceramic coating, probably vacuum-deposited before final bearing assembly or applied as a plasma coating."

Shift Lever and Actuator system update:
The shift lever sends a request to a chassis control module (CCM) for the trans range desired. The CCM commands the shift actuator to move the mechanical linkage to the desired position. The internal mode switch (position sensor) inside the trans sends a signal verifying the current gear range selected. The systems also have a "default to park" option when a malfunction occurs which will prevent vehicle movement until the fault is repaired.

ABOUT US
2017-2021 Chevrolet Bolt EV Drive Unit disassembly - A Youtube first! Join us for a deep dive into the incredible Chevrolet Bolt EV Traction Motor (part of the 1ET25 Drive Unit). Watch the drive unit disassembly and learn about the internal parts. This is the seventh in a series of videos on the 2017-2021 Chevrolet Bolt EV. Weber State University (WSU) - Department of Automotive Technology - Ardell Brown Technology Wing - Transmission Lab.

This video was created and edited by Professor John D. Kelly at WSU. For a full biography, see http://www.weber.edu/automotive/J_Kel...

ADDITIONAL TRAINING FOR YOU
Join us for hybrid and electric vehicle training with two online courses and in a 5-day on-campus boot camp with Professor John D. Kelly. See http://www.weber.edu/evtraining

DONATE TO OUR DEPARTMENT
Please consider a donation to the Department of Automotive Technology at Weber State University here: http://advancement.weber.edu/Automotive