TSB 93-25-11 4.9L New Longer Main Bearing Cap Bolts/Studs
Publication Date: DECEMBER 8, 1993
LIGHT TRUCK: 1993-1994 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" (4.572mm) 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 C2OZ-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.
NOTE: FOR SERVICE, THE SHORTER BOLTS AND STUDS MAY BE USED WITH OLDER OR NEWER CYLINDER BLOCK ASSEMBLIES
PART NUMBER PART NAME CLASS
F2TZ-6010-A Block Assy. - Cylinder (All 4.9L Engines) C
C2OZ-6345-A Bolt - 7/16-14 x 3.18" (All 4.9L Engines) B
C6TZ-6345-C Stud - 3/8-16 x 7/16-14 x 4.09" (All 4.9L Engines) BM
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: Information Only
OASIS CODES: 490000, 499000
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