# Volvo Electric overdrive: potential for EV shifting?



## jackbauer (Jan 12, 2008)

Triumph had that system on its passenger cars in the late seventies.


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## Woodsmith (Jun 5, 2008)

The overdrive will do that but the change in ratio, as you have said, isn't very large. It is really intended to be gear and a half so in 3rd you would have 3rd and a half ratio, in 4th you woul dhave 4th and a half.

The other problem could be its torque capacity. In direct drive it is essentially lock up as a solid unit with the drive torque transmitted through the cone clutch inside. That allows it to be used in all the gears.
Usually there is a lock out or an instruction to only use it in 3rd or 4th gear as an overdrive. That reduces the torque it has to handle. Using it in 1st or 2nd would put a lot of torque through the planetary gears and that may cause it to fail.


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