DETROIT DISEL 53
LIMITING SPEED MECHANICAL GOVERNOR AND
INJECTOR RACK CONTROL ADJUSTMENT
After adjusting the exhaust valves and timing the fuel injectors, adjust the governor and position the injector rack control
Loosen the load limit lever for the load limiting device, if the engine is so
equipped, before proceeding with the governor adjustment.
Adjust Governor Gap
With the engine stopped and at operating temperature, adjust the governor gap as follows:
1. Remove the high speed spring retainer cover.
2. Back out the buffer screw until it extends 5/8" beyond the governor housing.
3. Clean and remove the valve rocker cover.
4. Start the engine and adjust the idle speed screw (Fig. 5) to obtain an idle speed of 500-600 rpm.
The recommended idle speed is 500-600 rpm, but may vary with special engine
5. Stop the engine and remove the governor cover.
6. Start the engine and control the speed manually by operating the injector control tube lever. The engine speed
should be between 800 and 1000 rpm.
Do not overspeed the engine.
7. Check the gap between the low speed spring cap and the high
speed spring plunger with a .0015 feeler gage. If the gap setting is
incorrect, reset the gap adjusting screw (Fig. 1). If the setting is
correct, the .0015" movement can be seen by placing a few drops of
oil into the governor gap and pressing a screw driver against the gap
adjusting screw. Movement of the cap toward the plunger will force
the oil from the gap in the form of a small bead.
8. Hold the gap adjusting screw and tighten the lock nut.
9. Recheck the gap and readjust if necessary.
10. Install the governor cover. The governor cover should be placed
on the housing with the pin of the speed control lever projecting into
the slot of the differential lever.
11. Install the screws and lock washers finger tight. Pull the cover
away from the engine and tighten the screws. This step will properly
locate the cover on the governor housing.
Fig. 1 - Adjusting Governor Gap
Position Injector Rack Control Levers
The position of the injector racks must be 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. Adjust the rear injector rack control lever first to establish a guide for adjusting the remaining injector rack
1. Disconnect any linkage attached to the speed control lever.
2. Loosen all of the inner and outer injector rack control lever adjusting screws (Fig. 2). Be sure all of the levers are free
on the injector control tube.
3. Move the speed control lever to the full-fuel