SERVICE MANUAL
CRANKSHAFT, MAIN BEARINGS, FLYWHEEL & CRANKCASE
Section 6
The cast-in water-distribution passageway is plugged at
the rear of the case. A breather pipe aerates the
crankcase. The breather pipe is located below the
exhaust manifold with the element inside the crankcase,
on the “OLD” CRANKCASE MOUNTED ventilation
system.
However, the “NEW” VALVE COVER MOUNTED
ventilation system aerates the crankcase and reduces oil
carry-over through the crankcase breather. The breather
element, which requires service is located on the valve
cover.
400 Series Crankcase Revision
With the introduction of the NEW 400 SERIES TAPPET
(See Section 4), a new crank-case (IH P/N 1 802 330
C1) with a 28.524 mm (1.1230 in.) tappet bore diameter
has been released into production and service re-placing
the old style crankcase (IH P/N 675 500 C4) with 25.400
mm (1.0000 in.) tappet bore diameter. The new
crankcase can be identified by (IH Part No. 1 802 330
C1) appearing on the right hand side of the crank-case
as shown in Figure 4.
IMPORTANT: Some new crankcases (IH Part No. 1
802 330 C1) with 1.1230 in. Tappet bores will have
old (IH Part No. 675 500 C4) Rev. w/cost on the side
(Fig. 4). Identify 400 Series crankcase Revision by
Engine Serial Number.
Figure 4. - 400 Series Crankcase Identification
Engine
Serial No.
DT414B
155806 and above
DT436B
121623 and above
DT466B
140086 and above
DT466C
400001 and above
IMPORTANT: The crankcase (IH Part No. 1 802 330
C1) is a NON-SERVICE Part Number, to be used for
Identification only. Refer to appropriate parts
catalog when ordering parts.
400 Series Front and Intermediate Crankshaft Upper
Main Bearing Insert Revision.
A revised front and intermediate crankshaft upper main
bearing insert has been released with piston oil jet tube
holes (1, Figure 5) relocated to the center of the oil
groove (2, Figure 5). This change provides increased
load carrying capability of the bearing.
The “Old Style” bearing insert with “Offset” piston oil jet
tube holes (Refer to Figure 21) drilled to align with piston
oil jet tubes may be intermixed with the “New Style”
bearing insert. [Refer to Figure 20 to view “Old Style”
Insert]. The “New Style” bearing insert is designed to be
used WITHOUT changing the location of the piston oil jet
tubes in the main bearing. This is accomplished by
providing a large chamfer on the back side of the “New
Style” bearing (3, Figure 5) which assures proper oil flow
to piston oil jet tubes.
Figure 5. - "New Style" Bearing Insert
CGES-185-3
PRINTED IN UNITED STATES OF AMERICA
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