Fleetwood FWD V8-300 4.9L (1993)
Crankshaft Main Bearing: Technical Service Bulletins
Cylinder Block - Improvements and Main Bearing Usage
Bulletin No.
T-93-1
File in Group
6
Number
27
Corp. Ref. No.
216104R
Date
Nov. 1992
SUBJECT:
CYLINDER BLOCK IMPROVEMENTS AND MAIN BEARING USAGE
MODELS AFFECTED:
ALL 1991-1993 4.5L AND 4.9L V8 ENGINES
During the 1991 model year the cylinder block used for the 4.5L and 4.9L transverse V8 engines received a series of structural enhancements that have
made dimensional adjustments in main bearing clearance necessary to prevent main bearing knock (mallet noise) in some vehicles. These crankcase
changes are not incorporated in all 1991 vehicles, but are included for all 1992 and later engines. The improved crankcase is also used to assemble
service engine assemblies produced after 09/01/91 (i.e., a service engine built in 1992 calendar year for use in any model year including past models will
include the structurally updated transverse crankcase). Refer to Figures 1 and 2 to identify the updated crankcase.
The procedure necessary to establish which bearing (standard or oversize) should be installed in the # 1 or # 5 position, is contained in 1987 and later
Service Information Manuals. This procedure applies to all 4.5L and 4.9L V8 engines. Bearing position # 1 has the most influence on mallet noise.
