Final pinion bearing preload test – Spicer Tandem Drive Axle Dual Range & Double Planetary 34,000-45,000 lbs User Manual

Page 21

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Final Pinion Bearing Preload Test

1.

Assemble the complete pinion bearing cage unit as recommended

in the assembly section of this manual.

NOTE:

Forward axle pinion is equipped with helical gear. For easier

disassembly during bearing adjustment procedure, use a dummy yoke

if available) in place of helical gear.

.

2.

Apply clamp load to the pinion bearing cage assembly. Either install

the yoke (or helical gear) and torque the pinion nut to specifications or

use a press to simulate nut torque (see chart below).

Vise Method

- If the yoke and nut are used, mount the assembly in a

vise, clamping yoke firmly.

Press Method -

If a press is used, position a sleeve or spacer so that

load is applied directly to the back-face of the outer bearing cone.

.

3. Measure Pinion Bearing Preload -

Use a spring scale to test the

assembly rolling torque. To use the spring scale, wrap soft wire around

the bearing cage, attach the scale and pull. Preload is correct when

torque required to rotate the pinion bearing cage is from 15 to 35 inch

pounds. This specification is translated into spring scale readings in the

chart below.

4. Adjust Pinion Bearing Preload -

If necessary, adjust pinion bearing

preload. Disassemble the pinion bearing cage as recommended in this

manual and change the pinion bearing spacer. A thicker spacer will

decrease preload. A thinner spacer will increase preload.

IMPORTANT:

Use the correctly sized spacer. Do not use shim stock or

grind spacers. These practices can lead to loss of bearing preload and

gear or bearing failure.

Specifications for Final Pinion

Spring Scale Reading

Bearing Preload Test

(without pinion seal)

("Press-fit" Outer Pinion Bearing)

(for 15-35 in-lbs. torque)

Nut Torque

Press Loads

(1.7-4 N.m)

Axle Models

Ft-lbs.

N.m

Tons

Metric Tons

lbs.

kgs.

Forward Axles

SELF-LOCKING NUT

D340, 380(P),

400-P

560-700

759-949

13.5-15.5 12.2-14.0

5-12

2.3-5.4

D341, 381(P),

SELF-LOCKING NUT

401-P, 402(P),

780-960

1057-1301

17-19

15.4-17.2

5-12

2.3-5.4

451 -P

SLOTTED NUT & ROLL PIN

840*

1139*

17-19

15.4-17.2

5-12

2.3-5.4

METRIC NUT (After 7-1-95)

840-1020

1140-1383

17-19

15.4-17.2

Rear Axles

(all models)

560-700

759-949

14-15

12.7-13.6

6-14

2.7-6.4

METRIC NUT (After 7-1-95)

575-703

774-955

*Torque nut to 840 ft-lbs. (1139 N´m), then continue tightening nut to align nut slot to nearest hole in pinion shank.

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