M/T - High Pitched Sound From Extension Housing

NUMBER: *03-70-12R*
DATE: 12/13/12
*REVISED: 01/03/13*

APPLICABILITY:
Legacy and Outback 2000-2009MY w/ 5MT
Forester 1999MY and Later w/ 5MT
Impreza (Including WRX) 1999MY and Later w/ 5MT

SUBJECT:
Repair Procedure for High-Pitched Sound from Extension Housing Area Using Latest Generation Production Parts

INTRODUCTION
This Bulletin provides production change, repair procedure and parts information to address a customer concern of a high-pitched sound coming from the transmission extension housing area.

In cold temperatures, thermal contraction causes shrinking of the transmission case. In high temperatures, expansion of the case occurs. These temperature changes affect the amount of pre-load on the transfer driven shaft bearings. In some rare cases, when preload is very near the limit of specification combined with unusual driving conditions, this thermally-induced pre-load change may cause damage to the bearings and result in the sound heard by the customer.





A change has been made to the extension case and a new "Dish Plate" added. The machining depth of the extension *case* has been increased to accommodate the new dish plate. When used along with a selective thrust washer, the spring tension of the dish plate helps to maintain a consistent amount of pre-load on these bearings throughout varying temperature conditions.

COUNTERMEASURE IN PRODUCTION





The chart indicates the starting vehicle identification numbers (VINs) when the new parts were incorporated in to production.





PART INFORMATION

SERVICE PROCEDURE / INFORMATION





^ See Service Bulletin 03-68-12R for special tool information and a required bearing pre-lubrication procedure (shown below) related to this repair.

IMPORTANT:
If the transfer driven shaft bearings are damaged or failed, thoroughly clean and inspect all the internal components of the transmission before reassembly. In very severe cases where metal contamination damage is extensive, transmission assembly replacement may be required. If within the warranty coverage period, completion of an Assembly Repair vs. Replacement worksheet is required.





^ Follow the procedures in the applicable Service Manual for removal and replacement of the extension *case*.

*NOTE:
Both outer races of the transfer driven shaft bearings are hand-fit to their bores and are not press-fit. Turning the outer races slightly will make their installation easier.*

MEASUREMENT PROCEDURE





^ Measure height "W" between transfer case sealing surface and taper roller bearing outer race on the transfer driven gear.





^ With the bearing outer race, dish plate and thrust washer removed, measure depth "X" of the bearing bore of the extension case.

^ Calculate the required thrust washer thickness "T" using the revised formula below:

*T= X - W - (1.715 to 1.765 mm (0.0686 to 0.0706")).*

NOTE:
This formula has been revised from the formula shown in the Service Manual to work with the new dish plate and extension case assembly.





^ Select the thrust washer with the closest value from the table.





^ Once the proper thrust washer has been selected, assemble the *new* extension case as shown in the illustration.

^ *Install a new output oil seal before transferring the original metal dust cover over to the new extension case.*

^ Follow the procedure in the applicable Service Manual for re-installation of the new extension case assembly to the transfer case.

WARRANTY / CLAIM INFORMATION

For vehicles within the Basic New Car Limited Warranty period, refer to Subaru Warranty Wizard for claim submission information.





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