Harmonic Balancer - Crankshaft Pulley: Service and Repair

CRANKSHAFT PULLEY

REMOVAL AND INSTALLATION

Pre-removal & Post-installation Operation:

Removal Steps 1-4:

Required Special Tools:
^ MB992278: Belt Tension Release Wrench
^ MB990767: Front Hub and Flange End Yoke Holder
^ MD998719: Pin

REMOVAL SERVICE POINTS

[A] DRIVE BELT REMOVAL
To introduce the serpentine drive system with the drive belt auto-tensioner, the following operations will be required.

CAUTION:
To reuse the drive belt, draw an arrow indicating the rotating direction on the back of the belt using chalk to install the same direction.





1. Rotate the pulley bolt of the auto-tensioner counterclockwise with an special tool MB992278 and insert the L-shaped hexagon wrench into the auto-tensioner hole to fix the auto-tensioner.
2. Remove the drive belt.





[B] CRANKSHAFT PULLEY CENTER BOLT/CRANKSHAFT PULLEY WASHER REMOVAL





1. Hold the crankshaft drive sprocket with special tools MB990767 and MD998719.
2. Loosen the crankshaft pulley center bolt and remove the crankshaft pulley center bolt and crankshaft pulley washer.

INSTALLATION SERVICE POINTS

[A] CRANKSHAFT PULLEY/CRANKSHAFT PULLEY WASHER/CRANKSHAFT PULLEY CENTER BOLT INSTALLATION





1. Wipe off the dirt on the crankshaft and the crankshaft pulley as shown in the figure using a rag.
2. Wipe off the dirt on the crankshaft sprocket, the crankshaft and the crankshaft pulley as shown in the figure using a rag, and then degrease them.

NOTE: Degrease them to prevent drop in the friction coefficient of the pressed area, which is caused by oil adhesion.

3. Install the crankshaft pulley.
4. Wipe off the dirt on the crankshaft pulley washer and the crankshaft pulley center bolt as shown in the figure using a rag.
5. Apply an adequate and minimum amount of engine oil to the threads of the crankshaft pulley center bolt and the lower area of the flange.





6. Hold the crankshaft pulley with special tools MB990767 and MD998719 in the same manner as removal.
7. Tighten the crankshaft pulley center bolt according to the following procedure.
1) Tighten the crankshaft pulley center bolt to the specified torque 250 Nm (184 ft-lb).
2) Loosen the crankshaft pulley center bolt fully.
3) Tighten the crankshaft pulley center bolt to the specified torque 110 Nm (81 ft-lb).





4) As shown in the illustration "A," apply the paint mark to the crankshaft pulley on the extended line of the corner adjacent to the one of the crankshaft pulley center bolt corners.

CAUTION:
^ When the tightening angle is smaller than the specified tightening angle, the appropriate tightening capacity cannot be secured.
^ When the tightening angle is larger than the specified tightening angle, remove the bolt to start from the beginning again according to the procedure.

5) Tighten the crankshaft pulley center bolt by 60 degrees angle once more. Make sure the paint mark of crankshaft pulley center bolt is aligned with the paint mark of crankshaft pulley as shown in the illustration "B."

[B] DRIVE BELT INSTALLATION

CAUTION:
^ To reuse the drive belt, install it by aligning the arrow mark on the backside of belt marked at the removal with the rotating direction.

^ Check that the notches of the notched pulley and the notches of the drive belt are fit correctly.
^ Check that the drive belt is installed in the center of the flat surface of the flat pulley.





1. Install the drive belt to each pulley as shown in the figure.





2. Set an special tool MB992278 to the pulley bolt of the auto-tensioner. Then, rotate the auto-tensioner counterclockwise and remove the L-shaped hexagon wrench fixing the auto-tensioner.
3. Apply tension to the drive belt while slowly turning the auto-tensioner clockwise.