> The tranny will be rebuilt but I need some help and
> info. I heard that a saginaw 3 speed overdrive unit will work with the
> saginaw 4 speed. What I need is how to do this, how to
> wire it up and where can I find this unit in a manual if I need to take
> it apart
I have a Saginaw with the above OD conversion. It's explained fairly well in
the tech pages at www.chevytrucks.org. Basically you take the 3 speed OD
mainshaft and planetary OD gears in the tailshaft, build the 4-speed on this
base unit, and then slide it all back into the 4-speed case. The Patrick's
shifter will have to be moved up and toward the driver, to clear the OD
solenoid. The factory OD wiring includes a kickdown switch, speed governor,
ignition cutout circuit and relay. Switch and relay are no longer available
from GM so you'll have to improvise.
The Saginaw transmission overdrive is covered in "Chevrolet Chassis
Overhaul Manual", clutch and transmissions section. This would be circa
1970. Also very helpful is Borg-Warner transmission overdrive covered in
55' - '62 manual. Same design but different dimensions, some parts
interchange.but Borg Warner OD will not fit the Saginaw transmission.
You can contact me off list for more info.
Jack / Winter Park FL
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