Chevrolet Volt Transaxle Overview Video - 4ET50

Scott from Claremont Manager Posted   Latest  
2013 Chevrolet Volt 1.4L (4 LUU) (4ET50)

As a Volt owner, I've always been in pursuit of any knowledge I can gain about this platform. Back in 2013, I began researching how the transmission works and came away more confused than ever but still continued to try and understand. About a year ago I came across a Video that John Kelly from Weber State University produced that helped me understand how this unit works. I can say that after 100k miles on this vehicle everything is continuing to operated the way it performed 5.5 years ago.


About 18 years ago I was asked to present at Weber State at a conference which I found to be an outstanding institution for education. If you know of someone whom may be interested in an associates degree or bachelors degree in Automotive Technology, here is the web address:


For more info on Professor John D. Kelly at WSU:



Dr. from Port Angeles



Hi Scott:

Thanks for posting the video from John Kelly.......there is significant effort in making the video. It provides some great background on the Volt trans and a great starting place for any person wanting to learn more. I think there is significantly more that can be explored and added to items like the Volt trans, whether it be Ford, Tesla, Kia, GM, Toyota, Lexus, etc. within the Diagnostic Network. In my opinion, the industry is at a point where it needs to start moving past some of the basic elements of Vehicle Electrification (VE) systems and begin to transition into more complex areas of VE in which members of the network can grow their knowledge and understanding. The transition into more complex areas will uncover some areas for individuals that, will identify areas in which growth is needed.

As a member of the Diagnostic Network, FutureTech Auto (futuretechauto​.​com) and … are committed to supporting the network in growing the learning of, testing, and diagnosing of OEM VE systems. This will be a wonderful network those that seek more complex information respository of support and guidance.

Best Regards,



Scott from Claremont



Thanks for your support Mark, we greatly appreciate your partner support.


Kevin from Leesburg



Hi Scott,

When the volt was first launched, GM engineering had a great video they shared with technical communities. I found this video on YouTube and it is now available for everyone to see. Here is the link:


I am glad to hear this transmission is holding up well. Thanks for sharing!



Scott from Claremont



Thanks Kevin, 

I too saw this video prior to purchasing my Volt when SAE held a meeting locally here at Cal State Fullerton in … They had several engineers explaining the challenges they faced and the accomplishments achieved. The info I learned at that meeting and the fact that my commute was exactly 37mi (one way) led me to purchasing the Volt. Last, year I was able to visit the Advanced Battery Lab at the Warren Tech Center. What I observed there was extremely interesting and left me wanting more...

Today I have 100k miles with approximately 90k are all-electric. 


Kevin from Leesburg



That is an awesome testimony to the Volt. Back in 2011 I was working for GM STC. I was the subject matter expert who developed the training for the GM technicians on the 4ET50. I spent quite a bit of time in the ABL as well. I enjoy walking around the ABL and looking at the archives they have there. It is a very special place for people who appreciate EVs. 


James from Plant City



Here's a very interesting study on the Volt transmission in extended range mode.



Scott from Claremont



Thanks James,

I remember reading that article way back and even reached out to WOT for more info. We collaborated on and off over the years and about a year and a half ago, he let me know who he was and I was pleased to find out that we’ve met in the past. I do stay in touch with him and chat time to time. Perhaps sometime in the future he’ll be here to share more interesting information.

I love these diagrams since it allows one to gain a deeper understanding on power flow backed up by recorded data.


Martin from Burnaby



Hi Scott. I created the diagram below when the Gen 1 Volt was first introduced, so that I could better understand how the system functioned, by organizing the EDU components as assembled in the case, except for rotating the planetary gear set for improved viewing.

Coupled with the original Volt Electric Drive pdf and the full length Volt Deep Dive video, I was able to interpret how the system functioned and what all of the "hoopla" was about.