Marking TDC On Front Cover
- Rotate crankshaft until cylinder No. 1 is on TDC of compression stroke (timing marks on injection pump gear and camshaft gear will be aligned, and slot in injection pump gear will be in 6 o'clock position). See Figure and Fig 1.
- Install Timing Fixture (J-33042) in place of injection pump without gasket. Install injection pump gear bolts to fasten gear to timing fixture. Install nut finger tight on upper front cover stud to secure timing fixture.
- Tighten large bolt (18-mm head) on timing fixture to 35 ft. lbs. (47 N.m). Tighten nut on upper front cover stud. Ensure crankshaft did not rotate and timing fixture is not binding. Strike scriber with hammer to mark TDC indicator on front housing. See Fig 1. Remove timing fixture.
Courtesy of GENERAL MOTORS CORP.