Hooking up Speedometer and Calibrating Output

 The overdrive unit is supplied with an extension speedometer drive cable.  Disconnect the speedometer cable from the Ghost’s transmission and attach it to the extension cable using the signal generator sensor (Photo 17) to mate the two cables.  You may have to fabricate an adapter to mate the Ghost’s speedometer cable to mate the overdrive cable.  This is a good opportunity to check and lubricate the speedometer cable. 

 The speedometer should read correctly at all speeds, both in overdrive and without overdrive, since it is connected directly to the output shaft of the overdrive. The plate behind the speedometer coupling on the overdrive houses the speedometer drive gears and can be changed to match tire size and rear axle ratio (Photo 20).  Gear Vendors uses standard plastic speedometer gears designed for a GM turbo 400 transmission (Table 3).  Note: Gear Vendors overdrives sold prior to December 2000 have a different internal drive gear and Table 3 is not applicable.  Contact the author for information regarding speedometer gears for units sold prior to December 2000.

Section 1 - Disconnecting Torque Tube
Section 2 - Removing the Front Section of the Torque Tube
Section 3 - The Mathematics of an Overdrive
Section 4 - Checking Universal Joint and Bearnings
Section 5 - Installing Overdrive in Drive Line
Section 6 - Overdrive Lubrication
Section 7 - Connecting Speedometer and Electric Controls
Section 8 - Hooking up the Electronic Control Box
Section 9 - Hooking up Speedometer and Calibrating Output
Section 10 - The Overdrive in Operation
Section 11 - Overdrive Service
Section 12 - Crusing in Overdrive
Endnotes - Endnote
Table 1 - Silver Ghost Rear Axle Gear Ratios Comparisons
Table 2 - Engine Revolutions per Tire Turn
Table 3 - Overdrive Speedometer Gears for the Silver Ghost