Spicer Drive Axles Service Manual - Manual (Page 15)

13
PINION POSITION
Ring gears and pinions are supplied in matched sets
only. Matching numbers on both the pinion and ring
gear are etched for verification. If a new gear set is
being used, verify the numbers of each pinion and ring
gear before proceeding with assembly. (See
Gear Set
Identification, pg. 2)
Pinion position is based on the nominal mounting
distance measured from the centerline of the ring gear
to the nose of the pinion. This dimension is controlled
by selectively shimming between the pinion cage
assembly and the carrier housing. The nominal dimen-
sion is 3.976 in. (100.990 mm).
NOTE: Be sure mounting surfaces and shims are free
of burrs and dirt prior to assembly as they will affect
pinion position.
1. To establish the correct nominal dimension by using
a pinion setting gauge, install pinion and cage
assembly into the carrier housing without shims.
Tighten pinion cage bolts to correct torque specifi-
cations. (See
Axle/Torque Specifications, pg. 21)
Failure to tighten properly may result in incorrect
gear adjustment.
2. Attach the step plate clamp assembly to the carrier
mounting flange. Locate step plate clamp screw
over center of pinion. Install step plate under clamp
screw and tighten to hold step plate securely in
position.
NOTE: Be sure lugs on bottom of step plate straddle
the bearing staking indentions on end of pinion, or
NOTE: Because the step plate must be taken into
consideration, the thickness of the step plate (.400
in. (10.16 mm) needs to be added to the measured
value for the correct micrometer distance.
4
.
On the machined end of each pinion either a plus
(+), minus (-), or a zero (0) will be etched. (See
Gear Set Identification, pg. 2) This number
represents the amount in thousandths of an inch
(.001) to be added or subtracted from the nominal
dimension for the best running position for that
particular gear set.
EXAMPLE:
If pinion is etched +3, the required mounting
distance is more than nominal by .003 in. (.076
mm). This means the pinion would require .003 in.
(.076 mm) thicker shim between pinion bearing
cage assembly and carrier housing that a pinion
etched with "0". If the pinion is marked -3, the shim
required between pinion gearing cage assembly and
carrier housing would be .003 in (.076 mm) thinner
than if pinion was etched "0".
false reading may occur. Also, make sure differential
side bearing bores are clean and free of nicks.
3. Remove any burrs and wipe clean differential bearing
bore I.D.'s. Turn micrometer 90 deg. to step plate.
Install assembled pinion setting gauge into bearing
bores of carrier housing until fully seated. Adjust
micrometer so it is directly over end of step plate.
Run the micrometer thimble down to measure the
distance between the center of the ring gear and the
step plate.
See Figure 11. Make a note of this
dimension.
FFFFFigur igur igur igur igure 1 e 1 e 1 e 1 e 11 1 1 1 1
Pinion
Pinion Positon Shims
Nominal Mounting Distance
Ring Gear