Fleetwood Brougham V8-252 4.1L (1985)
4.
Remove main bearing cap and determine clearance by comparing width of flattened plastic gauging material at its widest point, with
graduations on plastic gauging material container. Number within matching graduation on envelope indicates clearance (Figure 1).
-
If clearance is less than .002", leave the red bearing (P/N 18014329) in the engine.
-
If clearance is .002" or greater, install the service #1 main bearing (P/N 18014307), which can be identified by its blue edge
color.
NOTICE:
These two new bearings (P/N 18014329 and 18014307) may only be used in the #1 main bearing bore due to horizontal dimensional
change. If these bearings are installed in the #2 or #4 main bearing bores, crankshaft to bearing interference may result under certain
temperature conditions which may cause severe engine damage.
2.
Main Bearing Update
Bearings #2 through #5 do not significantly contribute to HT4100 engine knock. They have, however, been updated as a result of research on the #1
bearing.
A.
#2 and #4 Main Bearings
P/N 18009086 has been superseded in production by a slightly thicker bearing. The new bearing (P/N 18013442) should be used whenever
replacement of #2 and/or #4 main bearings is required.
B.
#5 Main Bearing
P/N 18009087 has been superseded in production by a slightly thicker bearing. The new bearing (P/N 18013793) should be used whenever
replacement of the #5 main bearings is required.
In addition, service technicians have been provided the ability to reduce operating clearance of the #5 main bearing, if it is suspected as a
source of bearing noise by the release of a new oversize #5 bearing. This bearing (P/N 18012878 - identified by its blue edge marking) should
be installed if the clearance checking procedure described above for the #1 bearing is performed on #5 and the resulting clearance is .002" or
greater. Measurement with a new production bearing must always be performed to make this decision.
C.
Bearing Identification
To eliminate potential confusion resulting from the various part numbers associated with the main bearing revisions, the following chart is
provided for your information.
Service
Bearing
Edge
Part
Part
Application
Position
Color
Number*
Number**
Status
Original Production
#1
None
18006622
18009086
Obsoleted by 18012316
2nd Design Production
#1
Purple
18012275
18012316
Obsoleted by 18014329
3rd Design Production
#1
Red
18014079
18014329
Service Only O.S.
#1
Blue
18012276
18012317
Obsoleted by 19014307
Service Only O.S.
#1
Blue
18014306
18014307
Original Production
#2 & #4
None
18006622
18009086
Obsoleted by 18013442
2nd Design Production
#2 & #4
None
18013016
18013442
Original Production
#3
None
None
18009088
Original Production
#5
None
None
18009097
Obsoleted by 18013793
2nd Design Production
#5
Pink
None
18013793
Service Only O.S.
#5
Blue
None
18012878
*
Part number is number stamped on back of bearing shell. Use this number for identification.
**
Service number is number GMWDD assigns to part and prints on box. Use this number for ordering
parts.