Main Bearing Cap Bolts/Studs - Revised Design

Article No.
93-25-11

12/08/93

ENGINE - NEW LONGER MAIN BEARING CAP BOLTS/STUDS - 4.9L ENGINES BUILT AFTER 9/1/93

LIGHT TRUCK:
1993-94 BRONCO, ECONOLINE, F-150-350 SERIES

ISSUE:
Beginning approximately September 1, 1993, a change occurred with the 4.9L block and with the main bearing cap bolts and studs. Main bearing cap bolt holes in the block were drilled and tapped 0.18" (4.572 mm) deeper than in previous engines. The change in drilling depth was necessary to retain bolt commonality with the new longer 5.0L main bearing cap bolts at the engine assembly plant.

ACTION:
When service is required on 4.9L engines. Use only the proper (shorter) bolts and studs (service bolt C20Z-6345-A, service stud C6TZ-6345-C) for all engines. The new longer main bearing cap fasteners will not be released for servicing 4.9L engines.








CAUTION:
THE NEW LONGER MAIN BEARING CAP BOLTS AND STUDS MUST NEVER BE USED WITH BLOCK ASSEMBLIES BUILT BEFORE 9/1/93. IF LONGER BOLTS AND STUDS ARE USED IN AN OLDER BLOCK ASSEMBLY, A LOOSE MAIN BEARING CAP MAY OCCUR, RESULTING IN SERIOUS ENGINE DAMAGE. Refer to Figures 1 and 2.

NOTE:
FOR SERVICE, THE SHORTER BOLTS AND STUDS MAY BE USED WITH OLDER OR NEWER CYLINDER BLOCK ASSEMBLIES.





Parts Block


OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES: 490000, 499000