Engine - Timing Belt Tensioner Bracket Modification
NUMBER: 02-93-04DATE: 11/05/04
APPLICABILITY:
Legacy, Impreza and Forester Vehicles
SUBJECT:
Modification of Timing Belt Tensioner Bracket
INTRODUCTION
This Service Bulletin is to inform of a modification made to the timing belt tensioner bracket to prevent a knocking noise. On SOHC engines, the shape of the bracket and the size of the 2 (upper side) installation belts were changed. On DOHC engines, the shape of the bracket was changed and ribs added to increase rigidity.
PRODUCTION LINE CHANGE
The new style tensioner brackets were used in production starting in February 2004.
Affected vehicles:
^ 2004MY Forester
^ 2005 MY Legacy and Impreza
The following are the approximate starting VINs:
PART NUMBER INFORMATION
COUNTERMEASURE INFORMATION
Also, a countermeasure was made to the timing belt tensioner, which has been incorporated in production since April 5, 2002.
^ A new heat treatment procedure was used to improve the hardness of the surface at the plunger to prevent poor sealing.
Identification of countermeasure belt tensioner
The color of the paint dot on the pulley bolt was changed from "Blue" to "Green" (see Figure 1) Lot number of belt tensioner: 020402 and after.
REPAIR PROCEDURES/INFORMATION
Identify if noise is coming from the timing belt tensioner or tensioner bracket when the engine is cold.
(1) With the hood raised, listen carefully where the noise is coming from. If the noise can be heard from around the timing belt cover area, there is a possibility that the noise is coming from the timing belt tensioner.
(2) Confirm if the noise is coming from the upper portion of the timing belt tensioner by using a stethoscope. If noise can be heard it's either coming from the tensioner or bracket. Inspect the belt tensioner; if the cylinder body of the timing belt tensioner has a notch from wear (see Figure 2) the tensioner will need to be replaced.
(3) If the engine number is 572570 for SOHC or 572928 for DOHC and after, replace the timing belt tensioner bracket.
(4) If the engine number is 572570 for SOHC or 572928 for DOHC and before, check to see if the cylinder body of the timing belt tensioner has a wear notch. If so, replace the timing belt tensioner. If the cylinder body of the timing belt tensioner does not have a wear notch, replace the timing belt tensioner bracket.
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