1963 Corvette: Service Bulletin: Powerglide Transmission Governor Operational Check

Subject:   Powerglide Transmission Governor Operational Check
Model and Year:   1963 Aluminum Powerglide
Source:  Chevrolet Technical Service Bulletin
Bulletin No:  DR #583
Section:   VII
Date:  April 4, 1963

TO:  ALL CHEVROLET DEALERS

Complaints of no-upshift on Aluminum Powerglide transmissions may be due to malfunction of the valve body or governor.  The governor operation should be checked first to save time.  This can be done by placing the vehicle on a hoist, disconnecting the vacuum modulator line and connecting a pressure gauge to the low servo apply pressure tap.  If the governor is functioning properly, there will be a noticeable drop in pressure at the speeds indicated below.