GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2001 🢒 Yukon XL - 2WD 🢒 Engine 🢒 Engine Mechanical - 4.8L, 5.3L, and 6.0L 🢒 Engine Block Valley Cover Installation

    Object Number: 490851 Size: SH

    Important: All gasket surfaces should be free of oil or other foreign material during assembly.

  1. Install NEW knock sensor oil seals (1) into the valley cover (2).

    2. Lubricate the seal surfaces with clean engine oil.


    Object Number: 65048 Size: SH
  2. Install the valley cover and NEW gasket.

    3. 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.

  3. Install the valley cover bolts.

    4. Tighten
    Tighten the valley cover bolts to 25 N·m (18 lb ft).


    Object Number: 309864 Size: SH
  4. Install the knock sensors.

    5. Tighten
    Tighten the knock sensors to 20 N·m (15 lb ft).


    Object Number: 309859 Size: SH
  5. Install the knock sensor wire harness.