Deve<
It probably depends on the type of overdrive transmission. I had a '55
that was a GM 3 speed with a Borg-warner overdrive unit. (Factory option
before GM had their own overdrive later).
It was wired from the ignition, to the kick down switch, to the speed
switch (governor), to the engagement solinoid. On that unit the Handle
under the dash was a "lockout", when it was pulled the overdrive would
NOT engauge, pushing it in allowed for normal operation.
The kick down switch is just a "normally closed" push button with a
bracket so the trottle lever would push it open at wide open throttle.
--
John Dorsey
Wauchula, FL
'49 Chevy Panel http://www.strato.net/~jrdorsey/truck.htm
'52 GMC Firetruck http://www.strato.net/~jrdorsey/fire/fire.htm
'51 Chevy suburban http://www.strato.net/~jrdorsey/burb/
Deve Krehbiel wrote:
>
> I am hoping someone here can help me with a problem I am anticipating. I
> have just installed a 3 speed standard transmission with overdrive in my 50
> deluxe cab. Its not the one I am doing the frame up resto on. Anyhow, from
> what I understand, it amounts to 6 speeds. 1st gear and then 1st gear in
> overdrive, etc. To engage the overdrive, there is two ways to do it. The way
> it was done originally, you had a kickdown switch on the carb base that when
> putting the gas pedal to the floor, disengaged the overdrive. (from what I
> understand). There is also a governor that takes it out of overdrive below
> about 30 mph.
>
> Since I don't have all the switch, cable and associated hardware nor do I
> have a clue how to wire all this, an old friend of mine who has lots of
> experience with these overdrives suggest I just put a toggle switch on the
> shifter and then do the switching into overdrive manually and not bother
> using the governor. Its not very elegant but it would work. The toggle
> switch engages the solenoid and puts it in overdrive on demand. Thats fine
> and all, but there is a problem with that.
>
> I have two other friends with this very setup that have ruined their
> overdrive tranny because they forgot to flip the switch out of overdrive
> before putting the truck into reverse. Apparently reverse is a very bad
> thing for these transmissions if left in overdrive.
>
> I am hoping someone here can help me with an electrical solution. I had in
> mind a system where any attempt to put it in reverse disengages the
> solenoid. I have noticed that when I put the tranny in reverse, there is a
> mechanical that moves it out of overdrive anyway, but for some reason, this
> system fails. Anyone can shed any light on this, please respond. A wiring
> diagram on how this trans was originally set up would be nice.
>
> Thanks!
>
> Deve Krehbiel
> Hesston, Kansas
> 1950 3100 * 1949 3600 * 1948 4400 * 50 3100
> www.speedprint.com/Deves50/index.html
>
> Ole Chevy and GMC trucks rule!
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