Switch Pitch

[Pat Ford]

On Tue, 26 Jan 1999, Guenther,Max wrote:

sounds like the new tc's have much more slippage, is that a correct 
assumption?? and the lockup tc is an attemp to restore what was lost
( I was a mechanic at a bmw,saab,subaru dealer in the 80's and live in 
car hell -> salted roads so I never got my hands on one of these)

> Date: Tue, 26 Jan 1999 14:34:34 -0500
> From: Guenther,Max <Mguenther at ASCO.COM>
> To: "'diy_efi at efi332.eng.ohio-state.edu'"
     <diy_efi at efi332.eng.ohio-state.edu>
> Subject: RE: Switch Pitch
> 
> I'd have to agree.  I did not know what it was for in my 63 Riviera.
> Substituted a 65 Riv engine and trans and did not connect the Variable
> pitch switch.  Had to idle it up kinda high so it would idle in gear.
> Chirped everytime I went from park to drive.  Once I found out what it
> was it turned out to be very smooth.
> 
> >
> >On Tue, 26 Jan 1999, Robert Harris wrote:
> >
> >> The switch pitch convertor was used to replace low gear of the four speed
> >> hydramatic transmission when GM upgraded the design to the
> >>"Turbo-Hydromatic"
> >> and was available only with the 400 and only on the heavier cars.  
> >> 
> >> Not so much a starting gear as a "passing" gear.  Nice smooth "downshift"
> >> unlike shifting gears - so as to not disturb the passengers and simply
> >> smoothly allow a nice increase in power to swoop around the peasants.
> >> 
> >VP convertors did give a noticeable diiference at lower speeds and they
> >were easily rewired to be switched low/high at will. Oddly enough, their
> >reason for existence was to reduce creep when idling in gear with the car
> >stopped.
> >
> >
> 

Pat Ford                           email: pford at qnx.com
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