Chevrolet Bolt EV Traction Motor - Deep Dive

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 by having one end with coated bearings, or they use ceramic bearing balls inside, or they use insulated bearing mounting frames on both sides, and provide a grounding carbon brush assembly to handle shaft grounding. A drawback of the coated bearing is that you must ensure 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 contact. However, depending on the exact coating applied, this coating can be both insulating and tougher than the bearing steel 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) specifying the desired trans range. 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 that prevents vehicle movement in the event of a malfunction 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 disassembly of the drive unit and learn about its 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