GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2004 🢒 GMC C Sierra - 2WD 🢒 General Information 🢒 Vibration Diagnosis and Correction 🢒 Engine Mount Replacement - Left Side

Removal Procedure

    Object Number: 401885 Size: SH
  1. If RWD vehicle, raise the vehicle to a height to work through the front wheelhouse opening. Refer to Lifting and Jacking the Vehicle in General Information.
  2. If 4WD vehicle, raise the vehicle in order to remove the front tires and wheels and support with jackstands.
  3. Remove the left front tire and wheel. Refer to Tire and Wheel Removal and Installation in Tire and Wheels.
  4. Remove the pushpins holding the left front fender wheelhouse inner panel (1).
  5. Remove the wheelhouse inner panel.

    6. Object Number: 657625 Size: SH

    Notice: Broken engine mountings can cause misalignment of certain drive-train components. Misalignment of drive-train components causes eventual destruction of the drive-train components.

    If one engine mount breaks, the rest of the engine mounts will have increased stress put on them. This could cause the rest of the engine mounts to break.

  6. Working through the wheelhouse opening remove the 3 bolts retaining the engine mount to the engine mount frame bracket.

    7. Object Number: 309158 Size: SH
  7. Remove the oil pan skid plate, if equipped.

    8. Object Number: 310119 Size: SH
  8. Remove the engine protection shield from the vehicle, if equipped.

    9. Notice: When raising or supporting the engine for any reason, do not use a jack under the oil pan, any sheet metal, or the crankshaft pulley. Lifting the engine in an unapproved manner may cause component damage.


    Object Number: 657613 Size: SH

    Important: When raising the engine only raise enough to separate the engine mount from the engine mount bracket. Raising any further will require removal of the fan shroud or the exhaust pipe .

  9. If RWD vehicle, using a suitable jack on the ground wire bolt bosses, raise the engine.

    10. Only raise the engine enough to separate the engine mount to engine mount bracket.

  10. If 4WD vehicle, attach a chain to the front of the engine. Use accessible mounting bolts for the generator mounting bracket and the power steering pump mounting bracket.
  11. Raise the engine with a suitable lifting device to remove the engine mount.

    12. Only raise the engine enough to separate the engine mount to engine mount bracket.


    Object Number: 657620 Size: SH
  12. Remove the bolts holding the engine mount to the engine.

    13. Object Number: 657623 Size: SH
  13. Remove the 2 through-bolts for the engine mount frame bracket.
  14. Remove the engine mount frame bracket.
  15. Remove the engine mount.

Installation Procedure

    Object Number: 657623 Size: SH
  1. Position the engine mount frame bracket on the frame. Do not install the bolts.

    2. Object Number: 657620 Size: SH
  2. Install the engine mount.
  3. Perform the following procedure prior to installing the engine mount bracket bolts.
    4. • Remove all traces of the original adhesive patch.
    • Clean the threads of the bolt with denatured alcohol or equivalent and allow to dry.
    • Apply threadlocker GM P/N 12345382 ( Canadian P/N 10953489) or equivalent to the bolts.

    Notice: Refer to Fastener Notice in the Preface section.

  4. Install the 2 through-bolts.

    5. Tighten
    Tighten the through-bolts to 75 N·m (55 lb ft).

  5. Install the bolts holding the engine mount to the engine.

    6. Tighten
    Tighten the engine mount bolts to 58 N·m (43 lb ft).

  6. Lower the engine.
  7. If 4WD vehicle remove the chain from the front of the engine.
  8. If 4WD vehicle, install the generator mounting bracket and the power steering mount bracket bolt.

    9. Tighten
    Tighten the mounting bracket bolts to 50 N·m (37 lb ft).


    Object Number: 657625 Size: SH
  9. Install the 3 bolts holding the engine mount to the engine mount frame bracket.

    10. Tighten
    Tighten the engine mount to engine mount frame bracket bolts to 65 N·m (48 lb ft).


    Object Number: 310119 Size: SH
  10. Install the engine protection shield and bolts.

    11. Tighten
    Tighten the engine protection shield bolts to 20 N·m (15 lb ft).


    Object Number: 309158 Size: SH
  11. Install the oil pan skid plate.

    12. Tighten
    Tighten the bolts to 20 N·m (15 lb ft).

  12. Install the left front tire and wheel. Refer to Tire and Wheel Removal and Installation in Tires and Wheels.
  13. Install the front fender wheelhouse inner panel
  14. Lower the vehicle.