electronic overdrive

[independent361]

Hi i know this may be a dumb question, but what exactly is an electronic overdrive and what does it do? I have a 1990 nissan pathfinder automatic 4x4 with EOD and im not sure if i should keep it on or off? Or what?

Thanks

Joey

 

[rattlecanpaint]

Usually Electronic overdrive is a torque converter lockup clutch that is electronically controlled. You only want to turn it off if you're towin something. It basically lockes the input of the torque converter to the output of the tranny so you have no slip through the torque converter.

 

[Rich]

Usually Electronic overdrive is a torque converter lockup clutch that is electronically controlled. You only want to turn it off if you're towin something. It basically lockes the input of the torque converter to the output of the tranny so you have no slip through the torque converter.

Whaaaa? are you confusing an electronically controlled (as opposed to a purely hydraulically controlled) transmission with the lockup clutch on a torque converter?

 

[sha_ba_do_bang]

Overdrive is simply 4th or 5th gear on most cars. Technically its when the output of the transmission is spinning faster than the input shaft from the motor. Which results in better fuel mileage at higher speeds

Electronically controlled overdrive is simply that, it is controlled by electronic solenoids and the ECM, and is usually turned on or off by a switch

Torque converter lockup is something totally different. It usually happens in Overdrive only and may feel like and "extra" shift in some cases

 

[rattlecanpaint]

Bwahahaha! Yea, I'm combining the two in my head somehow. Maybe too much abduction!

 

[atblis]

Depends

Depends on the vehicle. In the case of older Volvos, there's actually a separate overdrive unit on the back of the transmission. The electric switch is simply a solenoid that causes the OD to engage hydraulically.

I wouldn't run it past some of the manufacturers to call something an overdrive even though it technically is not.