Kinda OT: What does overdrive mean?

[gforbess at attglobal.net (Gordon Forbess)]

On Mon, 2 Feb 2004 12:11:08 -0500, "Kervin Ridgley"
<kridgley@brownscar.com> wrote:

>I had someone ask me what overdrive means in a transmission, but I don't =
>know.  Can someone explain it to me?  Thanks

Overdrive, as defined by VW for the 020 economy transaxle, was simply
a "cruiser" gear in 5th.. not really an OD.  Many years ago, an
overdrive unit was actually added at the rear of the transmission of a
traditional RWD car.  It was a 2 speed unit that upped the gear ratios
available for each gear.  In other words, a three speed trans became a
six-speed with the OD feature selected.

My old Studebaker V8 had and OD with 3 on the tree.  The OD feature
could be engaged or disengaged with a T-handle.  Accelerate to about
26mph, lift the gas pedal and the OD shifted up to the higher range,
regardless of gear.  Also had a kickdown switch if you needed a
passing gear.  OD engaged was "free wheeling" with no engine brake and
shifting without the clutch was quite easy.. except reverse :-)

My Ranger pickup has a 5 speed automatic OD trans which has the free
wheeling feature and can be deselected if you need the engine brake or
want to lock out shifting to 5th.  More of a true OD than the VW,
actually.


Gordon

75 Mk I/Drake 1.9
http://pws.prserv.net/gforbess/scirocco/scirocco.htm