Detroit Diesel — Adjust Booster Spring (Variable Speed Mechanical Governor)
Adjustments · Governor booster spring
From a Detroit Diesel service manual — check it applies to your exact model before use.
Procedure
- Move the speed control lever to the idle speed position.
- Loosen the booster spring retaining nut on the speed control lever and the lock nuts on the eye bolt at the opposite end.
- Move the bolt in the slot of the speed control lever until its center is on or slightly over center of an imaginary line through the bolt, lever shaft, and eye bolt; tighten lock nut.
- Start engine, move speed control lever to maximum speed and release; lever should return to idle.
- If lever does not return, reduce spring tension; increase tension until it will not return, then reduce until it does return, and tighten eye bolt lock nut.
- Connect the linkage to the governor levers.
Source: Detroit Diesel service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.