Spicer Tandem Drive Axle Dual Range & Double Planetary 34,000-45,000 lbs - Manual (Page 19)

I
Differential Carrier
Adjustments help provide optimum axle life and performance by correctly
positioning bearings and gears under load.
The tandem axles covered in this manual require the following adjustments:
Bearing Preload:
This adjustment is
Ring Gear Tooth Contact:
This adjust-
Input Shaft End Play (Forward Axles):
performed for both pinion and differ- ent positions ring gear and pinion This adjustment controls gear mesh
ential bearings. It maintains proper for best contact under load. Correct in the inter-axle differential. Proper
gear alignment by creating correct adjustment distributes torque evenly adjustment helps maximize life of all
bearing cone and cup relationship for over gear teeth and helps maximize power divider parts.
free rotation under load. The pinion gear set life.
pilot bearing does not require a pre-
load adjustment.
Adjust Input Shaft End Play
Specifications:
Input shaft end play requirements will vary with operat-
ing conditions, mileage and rebuild procedures. These variations are
shown in the following chart.
Input Shaft End Play Chart
New or Rebuild with new parts
NOTE:
Because of manufacturing
0.003" to 0.007" variations in individual parts,
correctly adjusted end play could
Rebuild with reused parts vary 0.010", after the unit is
0.013" to 0.017" rotated.
Acceptable End Play Tolerances when measuring as
a regular maintenance procedure with axle in truck.
Up to 0.060" with over 100,000
NOTE:
If end play exceeds limits,
miles or 1 year service off-road. disassemble power divider and
replace worn parts.
Up to 0.040" with less than 100,000
miles or 1 year service on-road.
Measure and Adjust End Play
IMPORTANT:
In September 1988, Spicer added a Spring and a Thrust
Button between the input and output shafts. End play tolerances are the
same for axles with or without this Spring and Button. However, end play
measurement procedure is different than-described below. Refer to Service
Bulletin Supplement at back of this manual for procedure variances.
1.
With power divider assembled to differential carrier, measure end
pay with dial indicator positioned at yoke end of input shaft. Move
input shaft axially and measure end play. If end play is not correct (see
chart), adjust as follows.
2.
Remove input shaft nut, flat washer and yoke. Remove bearing cover
cap screws and lockwashers. Remove cover and shim pack.
3. To increase end play, add shims:
desired end play . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.003" to 0.007"
pleasured endplay (Step)....... . . . . . . . . . . . . . . . . 0.001" - 0.001"
Add shims to provide desired end play . . . . . . . . . . . . . 0.002" to 0.006"
4. To decrease end play, remove shims:
Measured endplay (Step 1l) . . . . . . . . . . . . . . . . . . . . . . . 0.015" - 0.015"
desired end play . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.003" to 0.007"
Remove shims to provide desired end play . . . . . . . . . 0.012" to 0.008"
5.
To reassemble input shaft, install the adjusted shim pack and bear-
ing cover. Install cap screws and lockwashers. Torque screws to 75-85
ft-lbs. (101-115 N.m).
NOTE:
If difficulty is experienced in achieving correct torque on the
input yoke nut, torque the nut with truck on the ground and axle shafts
installed.
6.
Install yoke, flat washer and nut.
Tighten nut snugly. Tap end of
input shaft lightly to seat bearings.
7.
Measure input shaft end play
with dial indicator. If end play is
still incorrect, repeat Steps 2
through 6.
8.
With end play correct, seal shim
pack to prevent lube Ieakage, then
torque input shaft nut and cover
cap screws (see chart).
NOTE:
When power divider has
been disassembled and reassem-
bled, it may be desirable to adjust
end play by measuring bearing
cover clearance and calculating
shim pack size. For procedures,
see page 42.
Torque Chart
Input
Shaft Nut
Ft-lbs. N´m
1-5/8-18 780-960 1057-1301
*M42 X 1.5 840-1020 1140-1383
Bearing Cover
Cap Screw
1/2-13 75-85 101-115
(Grade 5)
*Metric Nut used on Axles produced after 7/1 /95
19