SERVICE MANUAL
VALVE TRAIN - CAMSHAFT, TAPPETS & PUSH RODS
Section 4
II.
Increased Cam Lobe Width and Forging
Diameter
To accommodate the increased diameter tappet the
camshaft with 19.05 mm (0.75 in.) wide cam lobe and
36.58 mm (1.44 in.) forging diameter has been released
into production and service replacing the old camshaft
with 76.26 mm (0.64 in.) wide cam lobe and 30.99 mm
(1.22 in.) forging diameter. [Refer to Figure 6].
IMPORTANT: Both New Camshaft (IH P/N 1 802 337
C1) and Displaced Camshaft (IH P/N 691 488 C1)
have the revised intake ramp height providing a
common intake and exhaust valve lash of 0.64 mm
(0.025 in.)
Engines built with and after the following serial numbers
incorporate the new style tappets and crankcase:
ENGINES
SERIAL NUMBER
D-414
Not Yet Available
D-436
Not Yet Available
D-466
Not Yet Available
DT-414B
155805
DT-436B
121623
DT-466B
140086
DT-466C
400001
Engines built with and after the following serial numbers
incorporate the new style camshaft:
ENGINE
SERIAL NUMBER
D-414
Not Yet Available
D-436
Not Yet Available
D-466
Not Yet Available
DT-414B
156104
DT-436B
121816
DT-466B
140841
DT-466C
400001
Figure 7. - Tappet Identification
The following is a list of acceptable combinations of camshafts, crankcases and tappets:
OLD STYLE
NEW STYLE
OLD STYLE
NEW STYLE
OLD STYLE
NEW STYLE
CAMSHAFT
CAMSHAFT
CRANKCASE
CRANKCASE
TAPPET
TAPPET
X
X
X
X
X
X
X
X
X
X
X
X
CGES-185-3
PRINTED IN UNITED STATES OF AMERICA
Page 4