Detroit Diesel — Adjust Governor Gap (Single Weight Governor)
Adjustments
From a Detroit Diesel operator's manual — check it applies to your exact model before use.
Procedure
- Remove governor high-speed spring retainer cover.
- Back out buffer screw approximately 5/8 inch.
- Start engine and adjust idle speed screw; tighten lock nut.
- Stop engine; remove governor cover, lever assembly, and valve rocker cover.
- Remove fuel rod from differential lever and injector control tube lever.
- Check gap between low-speed spring cap and high-speed spring plunger with gage J 5407 (170).
- Loosen lock nut and turn gap adjusting screw until slight drag is felt.
- Hold screw and tighten lock nut.
- Recheck gap.
- Install fuel rod and governor cover with new gasket.
Tools required
- Gage J 5407 (170) Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Slight drag on gage
Source: Detroit Diesel operator's 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.