New Holland CX720 Repair Manual page 1723

6. Replacing oil pump and timing system gear
Check that the teeth of the gear are neither damaged
nor worn, but if they are then take it out with an ap-
propriate extractor.
When fitting the gear (1) on the crankshaft (2) heat it
for approx. 15 minutes in an oven at a temperature
of 180 °C.
After driving it home, leave it to cool.
NOTE: For engine F3A only: After heating the gear, 1, fit
it on the shaft by applying a load of 6000 N (1350 lbf.) to
the gear, positioning the load at the distance shown in Fig.
140. After cooling, the gear must have no axial movement
under a load of 29100 N (6547.5 lbf.).
7. SELECTING MAIN AND BIG END BEARING
SHELLS
To obtain the required assembly clearances, the
main and big end bearing shells need to be selected
as described below.
This operation makes it possible to identify the most
suitable half bearings for each of the pins of the shaft
(the half bearings may even be of a different class
from one pin to another).
Depending on the thickness, the half bearings are
selected in classes of tolerance, marked by a colour
(red-green — red/black — green/black).
The following tables give the characteristics of the
main and big end bearing shells available as spares
in the standard (STD) sizes and in the permissi-
ble oversizes (+0.127, +0.254, +0.508 [0.0050 in,
0.0100 in, 0.0200 in]).
POWER PRODUCTION - ENGINE
2 4/7/2006
B.10.A / 177
9
MID0400A