GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1997 🢒 GMC P62 Commercial Chassis 🢒 Engine 🢒 Engine Mechanical - 6.5L 🢒 Camshaft Timing Chain and Sprocket Replacement

Removal Procedure

    Important: If the timing chain, the timing gears, the front cover, the crankshaft position sensor, the crankshaft, or other components affecting the timing are replaced, the TDC offset into the PCM will need to be reprogrammed.


    Object Number: 45924 Size: MH
  1. Remove the front cover. Refer to Front Cover Replacement.
  2. Measure the timing chain free play.
    3. 2.1. Mount a dial indicator to the front of the block.
    2.2. Position the dial indicator so that the plunger contacts the timing chain between the two gears.
    2.3. Pull the chain outward (parallel to the front of the face block) the maximum amount using finger pressure on the inside of the chain.
    2.4. Set the dial indicator to zero.
    2.5. Move the chain inward (parallel to the front face of the clock) the maximum amount using finger pressure on the outside of the chain.
    2.6. Note the total indicator travel. The deflection for used parts must not exceed 20.3 mm (0.80 in). If the deflection exceeds this limit, the sprockets and the timing chain must be inspected for wear and replaced as necessary. The maximum deflection for new parts must not exceed 12.7 mm (0.50 in).

    Object Number: 60259 Size: SH
  3. Remove the injection pump gear.

    4. Object Number: 43355 Size: SH
  4. Remove the camshaft gear. Align the timing marks.
  5. Remove the camshaft sprocket and the timing chain.
  6. Remove the crankshaft sprocket.

Installation Procedure

    Object Number: 43355 Size: SH
  1. Install the crankshaft sprocket.
  2. Install the camshaft sprocket and the timing chain.
  3. Align the timing marks on the camshaft gear.
  4. Install the camshaft gear with the bolt and the washer.

    5. Tighten
    Tighten the bolt to 100 N·m (75 lb ft).

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.


    Object Number: 60259 Size: SH
  5. Align the timing marks on the injection pump gear.
  6. Install the injection pump gear and the bolts.

    7. Tighten
    Tighten the bolts to 23 N·m (17 lb ft).


    Object Number: 43351 Size: SH
  7. Install the front cover. Refer to Front Cover Replacement.
  8. Adjust the injection pump timing when new gears, sprockets, or a timing chain is installed.