Why Does an EV Need a Transmission, Anyway?

by Britt
(Petaluma)

If an automatic transmission is such a bummer for EV conversions, why not just "can" the transmission and hook the electric motor to the drive shaft - save a little money and a lot of weight?

Hey, Britt -
There's a delightful dialogue on this very subject at the EV Discussion List, my favorite EV locker room. I think it's comprehensive enough that if you're serious about going tranny-free, I'd click on over and have a thorough read of this thread.

Here's the breakdown: Your donor usually already has a transmission. Right. Should it stay or should it go?
If it stays, you don't have to get rid of it.
If it stays, you have to get an adapter plate made by a machine shop.
If it stays, and it's an automatic, you've either got to teach it how to understand your electric motor's behavior through inventing and installing a simple alternative feedback system...or just leave it as it is and tolerate the loss of range.

If it goes, on the other hand...

...you lose some weight. Easier than Jenny Craig.

If it goes, you have to buy specific, and apparently more expensive, components.
If it goes, you need a bigger motor and controller to handle hills and such.
If it goes, you've got to remove the transmission, and then figure out what to do with it.

Nothing's ever as easy as it oughta be, is it?

Regards,
Lynne