Electric Car Conversion – Coupling The Motor To The Transmission

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Electric Car Conversion – Coupling The Motor To The Transmission

One of the trickiest processes of a DIY electric car conversion is coupling the electric motor to the transmission unit of the car. To make the connection work easier, it is recommended for you to take out the transmission and put in on a workbench. It involves a lot of work, but it will save you a lot of time and unnecessary headache.

When the electric motor and the transmission is on a workbench, you can now handle the alignment, get the holes drilled and get everything working.

To start of the connection process, there are 2 things you need to consider.

1) The physical piece of the electric motor.

You have to find a way to somehow bolt the motor to the transmission. The motor will be using an “L” shaped motor mount.

A lot of electric cars use a motor that mounts off the face and you’ll actually end up with a piece of metal plate between the electric motor and the transmission.

2) Connecting the power from the electric motor to the transmission.

When doing this, you will notice two different size and very different shaft. You will need to come up with a way to connect both together. The most common way electric car converters are adopting is to use a brand of connector calls Lovejoy connectors.

The connector comes with 2 pieces of steel with finger. There will be a piece of rubber insert that sits between them. The Lovejoy couplers are not very expensive and you can get them from Amazon.com.

You can order the steel pieces independently with different size hole to match the different shaft.

The Lovejoy couplers are designed for industrial work and are made to go right on the shaft of the electric motor. Look closely at the electric motor shaft. It is smooth except for a groove in it. That is where the “key” goes in.

The key is what keeps the coupler from spinning once it is on the motor shaft. That is how you connect the electric motor to the transmission unit of the donor car.

DIY Electric Car Conversion Guide

Do you want to find out more on how to convert your gas guzzler to a pure electric vehicle? If you do, check out Les Oke’s Convert2EV manual.

Les and his family live a green lifestyle and use an electric car for their daily commute. Les has converted numerous conventional automobile to EV. The Convert2EV e-book is all his EV conversion experience penned down.

==> Click here to visit Convert2EV now!

By | 2012-08-16T09:41:58+08:00 January 28th, 2010|Electric Motor|11 Comments

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  1. Tim January 29, 2010 at 12:11 am


    Will this device charge a battery to run an electric motor. I have seen were the charging unit can turn into an electric motor and run the car at low speeds, is that what this is?

  2. Will January 29, 2010 at 12:16 am

    Hi Tim,

    The Lovejoy unit is only a coupler that connects the shaft of the electric motor to the core of the transmission unit.

    The system that can generate power when the EV slows down is call the regenerative system. I wrote a short article about it. Check it out below.

    Regenerative Brake System On DIY EV

  3. […] connecting the electric motor to the existing transmission unit, most EV retrofitters will use the Lovejoy metal coupler. Putting the coupler on the motor shaft is easy. But how do you put the coupler on the transmission […]

  4. John March 3, 2010 at 1:48 am

    Can you tell me what the part number is for the Lovejoy coupler.

  5. Daniel March 4, 2010 at 3:51 am

    Will, how does the Lovejoy coupler work on the splined shaft of a transmission since it does not have a keyway?

  6. Will March 5, 2010 at 3:41 pm

    You can check out the complete range of shaft coupler from Lovejoy. Find the one most suitable for your needs.


  7. Will March 5, 2010 at 3:45 pm

    Without the keyway, your biggest challenge is the coupling slipping under high torque. You can weld it, but you have to make sure the weld is strong and there are no cracks.

    You can also check out the other motion control couplings from Lovejoy.


  8. Used Cars @ Dial a Demo August 12, 2010 at 3:02 am

    What I really love about the electric car revolution is that the technology is available to enthusiasts to DIY. It really harks back to the early days of motoring where loads ot enthusiasts built up their own cars. What really turned me onto the possibilities was when I read an article about electric drag cars, built by the enthusiasts themselves. As battery and motor technology improves things can only get better!

    In the meantime I am thoroughly enjoying your blog, and have you bookmarked as a favorite. Keep up the good work!


  9. Jonathan November 3, 2010 at 7:29 am

    What type of transmission is best to use? Manual or Automatic. Manual would probably be easier as the automatic needs a way to know when to shift..usually by vacuum from the engine. Im sure there is more modern automatic trans that could be used.

  10. Automatic transmission January 22, 2011 at 12:47 pm

    People would charge their cars mostly during the night. That’s when the demand for electricity is lowest. Only difference it would make is there would be no more “off peak” hours for electricity.
    The consumption would be more balanced than today. I think it would be actually a good thing for the power companies. They would need to adjust production much less.

  11. Jan Steinman May 7, 2011 at 7:36 am

    You certainly want a manual transmission.

    Typically, you won’t be shifting at all, so an automatic transmission is a complete waste of energy that will ultimately cost you perhaps 10% of your battery capacity.

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