Service Manual

4WD Rear Axle
Unit S/N 80001 - 99999
Rev. A
Reelmaster 5200-D/5400-D 4WD Rear AxlePage 9 - 13
(Unit Serial No. 80001 - 99999)
Pinion Gear to Ring Gear Engagement
Final position of pinion is verified by using the gear con-
tact pattern method as described in the following proce-
dure.
GEAR TOOTH DEFINITIONS (Fig. 13):
Toe−the portion of the tooth surface at the end to-
wards the center.
Heel−the portion of the gear tooth at the outer end.
Top Land−top surface of tooth.
1. Paint the teeth of the ring gear, both drive and coast
side, with a gear marking compound, such as DyKem
Steel Blue.
2. Install the pinion gear assembly.
3. While applying a light load to the ring gear, rotate the
pinion gear until the ring gear has made one complete
revolution. The drive side pattern should be located at
the toe portion of the tooth. The coast pattern should
also be at the toe portion of the tooth (Fig. 14).
Ideal tooth contact should cover more than 35% of each
tooth surface. The contact area should be in the center
of each tooth and extent 1/3 to 1/2 way across each
tooth from the toe end.
Adjustments to the gear engagement are made by mov-
ing the input shaft/pinion gear (bearing case shims) or
by moving the differential gear case (differential bearing
shims) (Fig. 15).
Note: Bearing case shims are available in 0.004 in.
(0.1 mm), 0.006 in. (0.15 mm), 0.032 in. (0.8 mm),
0.040 in. (1.0 mm), and 0.048 in. (1.2 mm) thickness
Note: Differential bearing shims are available in
0.004 in. (0.1 mm), 0.006 in. (0.15 mm), 0.032 in.
(0.8 mm), 0.040 in. (1.0 mm), and 0.048 in. (1.2 mm)
thickness.
Study the different contact patterns (Fig. 16 − 18) and
correct engagement as necessary.
NOTE: When making changes, note that two variables
are involved (see Gear Pattern Movement Summary in
this section of this manual).
Example: If you have the backlash set correctly to speci-
fications and you change the pinion position shim, you
may have to readjust backlash to the correct specifica-
tion before checking the pattern.
Figure 13
TOE
HEEL
PROFILE
TOP LAND
ROOT
LENGTHWISE
BEARING
ARC
Figure 14
DRIVE SIDE COAST SIDE
Heel
Toe
Heel
Toe
1. Input shaft/pinion gear
2. Bearing case shims
3. Differential gear case
4. Differential bearing
shims
Figure 15
1
2
3
4