Service Manual

Front Wheel Drive
Section (4WD)
The ring gear (32) and pinon gear (8) are supplied as a
matched set. Both gears are etched for verification with
matching numbers. If a new gear set is being used,
verify that the matching numbers are the same on both
the ring and pinion gear before assembling the front dif-
ferential (Fig. 43).
The distance from the center line of the ring gear to the
bottom of the pinion gear teeth is 3.750 inches (5.525
c
m). This distance represents the best running position
for the gear set (Fig. 42).
On the end of each pinion gear, there is an etched num-
ber indicated by plus (+), minus (–
), or zero (0). This
number indicates a shimming dimension for the best
running position of the gear set. This dimension is con-
trolled by shimming between the the bearing cup (10)
and the carrier assembly (15) (Fig. 43).
For example: I
f a pinion gear shaft is etched +4, this pin-
ion would require 0.004 inch less shims than a pinion
etched ”0”. By removing shims, the running position is
increased to 3.754 inches. The +4 represents a 0.004
inch increase in the running position. On the other hand:
If a pinion gear shaft is etched –4, this pinion would re-
quire 0.004 inch more shims than a pinion etched ”0”. By
adding shims, the running position is decreased to
3.746 inches. The –4 represents a 0.004 inch decrease
in the running position.
NUMBERS
SHIMMING
DIMENSION
MATCHING
Figure 43
When reusing an old ring gear and pinion gear shaft set,
measure the old shim pack thickness and build a new
shim pack to the same thickness. Measure each
shim
separately with a micrometer. Add each shim thickness
to get the total shim pack thickness.
If a new gear set is being used, note the (+) or (–) etching
on both the old and new pinion gear shaft. Change the
thickness
of the new shim pack to compensate for the
difference between these two dimensions.
For example: If the old pinion gear shaft reads + 2 and
the new gear is
–2, add 0.004 inch of shims to the old
shim pack (see Table 1).
Note: A
ll shims (14, 21, and 31) are available in thick-
esses of 0.003, 0.005, 0.010, and 0.030 inch.
Old Pinion
Marking
M
ar
ki
ng
New Pinion Marking
–4 –3 –2 –1 0 +1 +2 +3 +4
+4 +0.008 +0.007 +0.006 +0.005 +0.004 +0.003 +0.002 +0.001 0
+3 +0.007 +0.006 +0.005 +0.004 +0.003 +0.002 +0.001 0 –0.001
+2 +0.006 +0.005 +0.004 +0.003 +0.002 +0.001 0 –0.001 –0.002
+1 +0.005 +0.004 +0.003 +0.002 +0.001 0 –0.001 –0.002 –0.003
0 +0.004 +0.003 +0.002 +0.001 0 –0.001 –0.002 –0.003 –0.004
–1 +0.003 +0.002 +0.001 0 –0.001 –0.002 –0.003 –0.004 –0.005
–2 +0.002 +0.001 0 –0.001 –0.002 –0.003 –0.004 –0.005 –0.006
–3 +0.001 0 –0.001 –0.002 –0.003 –0.004 –0.005 –0.006 –0.007
–4 0 –0.001 –0.002 –0.003 –0.004 –0.005 –0.006 –0.007 –0.008
Table 1
1. If the bearing cone (9) was removed, press new
bearing cone onto the shaft of the pinion gear (8) (Fig.
44).
Figure 44
Workman 4000 Series Page 10
– 25
Rev. B
Front Wheel Drive Section (4WD)