DETROIT DIESEL 53
VARIABLE SPEED MECHANICAL GOVERNOR AND
INJECTOR RACK CONTROL ADJUSTMENT
The variable speed mechanical governor assembly is
mounted at the rear of the 6V engine, between the
flywheel housing and the blower (Fig. 1). The governor
is driven by the right-hand blower rotor drive gear.
After adjusting the exhaust valves and timing the fuel
injectors. adjust the governor and the injector rack
Adjust Governor Gap
With the engine stopped. adjust the governor gap as
1. Disconnect any linkage attached to the governor
2. Remove the governor cover.
3. Place the speed control lever in the maximum
Fig. 2 Adjusting Governor Gap
6. Install the governor cover.
4. Insert a .006" feeler gage between the spring
Position Injector Rack Control Levers
plunger and the plunger guide as shown in Fig. 2. If
required. loosen the lock nut and turn the adjusting
The position of the injector control racks must be
screw in or out until a slight drag is noted on the feeler
correctly set in relation to the governor. Their position
determines the amount of fuel injected into each
cylinder and ensures equal distribution of the load.
5. Hold the adjusting screw and tighten the lock nut.
Check the gap and readjust if necessary.
The letters R or L indicate the injector location in the
right or left cylinder bank as viewed from the rear of the
engine. Cylinders are numbered starting at the front of
the engine on each cylinder bank. Adjust the No. 3L
injector rack control lever first to establish a guide for
adjusting the remaining levers.
1. Loosen the lock nut and back out the buffer screw
2. Remove the valve rocker covers.
3. Remove the clevis pin from the fuel rod and the
right cylinder bank injector control tube lever.
Fig. 1. Variable Speed Governor Mounting
4. Loosen all of the inner and outer injector rack
control lever adjusting screws on both injector control
tubes. Be sure all of the injector rack control levers are
free on the injector control tubes.
1971 General Motors Corp.
SEC. 14.4.5 Page 1