Spicer Tandem Drive Axle Dual Range & Double Planetary 34,000-45,000 lbs - Manual (Page 20)

Adjustments
Pinion Bearing Preload
Most late model axles are provided with a “press-fit” outer bearing on
the drive pinion. Some of the early model axles use an outer bearing
which slips over the drive pinion. Procedures for adjusting both types
of pinion bearing design are contained in this section.
Adjust Pinion Bearing Preload for Axles with
.
“Press-fit” Outer Pinion Bearings
Trial Build-up
1.
Assemble pinion bearing cage,
bearings and spacer (without drive
pinion or oil seal). Center bearing
spacer between two bearing cones.
NOTE:
When new gear set or
pinion bearings are used, select
nominal size spacer from the speci-
fication chart below. If original
parts are used, use spacer removed
during disassembly.
2.
With the bearings well lubri-
cated, place the assembly in the
press. Position sleeve so that load
is applied directly to the back-face
of the outer bearing cone.
3.
Apply press load (see chart
below) to the assembly and check
rolling torque. Wrap soft wire
around the bearing cage, attach
spring scale and pull. Preload is
correct when torque required to
rotate the pinion bearing cage is
from 10-20 inch-pounds. This
specification is translated into
spring scale readings in the chart
below.
4.
If necessary, Adjust Pinion
Bearing Preload by changing the
pinion bearing spacer. A thicker
spacer will decrease preload. A
thinner spacer will increase
preload.
IMPORTANT:
Once correct bear-
ing preload has been established,
note the spacer size used. Select a
spacer 0.001” larger for use in the
final pinion bearing cage assembly.
The larger spacer compensates
for slight “growth” in the bear-
ings which occurs when they are
pressed on the pinion shank. The
trial build-up will result in proper
pinion bearing preload in three
of four cases.
IMPORTANT:
Do not assume that
all assemblies will retain proper
preload once bearings are pressed
on pinion shank. FINAL PRELOAD
TEST MUST BE MADE IN EVERY
I CASE.
Assemble these Parts for
Trial Build-up.
INNER INNER BEARING OUTER OUTER
BEARING BEARING SPACER BEARING BEARING
CONE CUP (vARIABLE) CUP CONE
Specifications for Pinion Bearing Spring
Trial Build-up Preload Test Scale Reading
(“Press-fit” Outer Pinion Bearings) (without
pinion seal)
Nominal Bearing
(for 10-20
Spacer Thickness Press Loads
in-lbs. torque)
(1.1-2.3 N•m)
Axle Models in. mm Tons Metric Tons lbs. kgs.
Forward Axles
D340, 380(P),
400-P 0.638 16.21 13.5-15.5 12.2-14.0 3-7 1.4-3.2
D341, 381(P),
401-P, 402(P),
451-P 0.496 12.60 17-19 15.4-17.2 3-7 1.4-3.2
Rear Axles
(ail models) 0.638 16.21 14-15 12.7-13.6 4-8 1.8-3.6
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