SUBJECT: Introduction of Camshaft/Oil Pump “Hunting Tooth” Gear Assemblies

MODEL: Valiant/Chrysler/Centura with ‘D’ Engine
 

Extensive investigations have been conducted to determine the reason for and corrective action required to overcome oil pump/camshaft gear failure occasionally experienced on ‘D’ series engines.

Warranty statistics reveal the majority of vehicles which experience this failure are operated by large fleet and government departments.  These failures usually occur at relatively low kilometre age, mainly due to engines not being run-in in accordance with Chrysler Australia Limited's recommendations.  Tests conducted by Engineering Department have confirmed that premature camshaft/oil pump gear failure can be induced by subjecting a new engine to high speed operation during the early service life of a vehicle. 

In an endeavour to prevent the possibility of this type of failure occurring, Dealers are requested to emphasise to new vehicle owners operators,  the importance of strictly adhering to the recommended running-in procedure published in the vehicle OPERATION AND MAINTENANCE MANUAL.  Reference to this requirement will also be included with the vehicle operating instructions  defined on the plastic sleeve which is fitted over the RH interior visor at the time of vehicle delivery.

To further improve gear durability,  effective in production concurrent with the introduction of engines that comply with ADR 27A emissions requirements,  (identified with engine prefix code ‘H’) camshafts/oil pumps incorporating revised valve timing together with a “hunting tooth” gear configuration (camshaft – 16 teeth/oil pump – 15 teeth) were introduced.  Although the number of teeth of the camshaft gear remains unchanged,  pre-emissions camshafts are not interchangeable with post emissions camshafts,  as the diametral pitch of the gear has decreased.  Post emissions camshafts are further identified with blue paint applied to either side of the oil pump gear,  together with the production date code metal stamped on the rear of the N0. 4 camshaft journal.

Listed below is a table in which camshaft/oil pump configurations are identified by part number:
 
 
 

In the event of fitting a post emissions camshaft to a pre-emissions engine,  a package comprising of a camshaft and oil pump gear is available from Parts & Service Division:
 
 

The oil pump driven gear supplied with this package can be fitted to a pre-emissions engine oil pump as described in instructions in Section 10-1A of the ‘K’ Series Service Manual.  The following special tools are required:

To remove Gear:   E9C70D

To install Gear:     E9C70F (fits 15 or 16 teeth gear)
                           E9C70C* (fits 16 teeth gear only)

* Tool No. E9C70C can be modified to fit either gears by increasing bore diameter of tool 0.030” in the area that fits over gear  (i.e. 1.255” to 1.285”).  Failure to modify this tool will contribute to damage of gear occurring when installing gear to oil pump shaft.