GMC 1989 Light Duty Truck Repair Manual page 189

S U B J E C T
93/4-lnch Ring G e a r .................................................................................................................................................................... 4B 5- 1
D escriptio n ............................................................................................................................................................................... 4 B 5 - 1
Checking the Axle Before Disassembly........................................................................................................................... 4 B 5 - 1
Diassembly of the Rear A xle................................................................................................................................................4B 5- 2
C le a n in g .................................................................................................................................................................................... 4B 5- 2
Inspection..................................................................................................................................................................................4 B 5 - 2
Assembly of the Rear A x le ..................................................................................................................................................4 B 5 - 7
101/2-lnch Ring G e a r ..................................................................................................................................................................4B 5-13
D escription............................................................................................................................................................................... 4B 5 -1 3
Checking the Axle Before Disassem bly........................................................................................................................... 4B 5 -1 5
Disassembly of the Rear A xle ............................................................................................................................................. 4B 5-15
C le a n in g .................................................................................................................................................................................... 4B 5 -1 8
Inspection..................................................................................................................................................................................4 B 5-18
Assembly of the Rear A x le ..................................................................................................................................................4B 5-19
S p e c ific a tio n s ............................................................................................................................................................................. 4B 5 -2 7
Special T o o ls ............................................................................................................................................................................... 4B 5-28
DESCRIPTION
The D ana 9 3/4-inch rin g g e a r rea r axle uses a
conventional ring and pinion gear set to transm it the
driving force of the engine to the rear wheels. This gear
set transfers this driving force at a 90 degree angle from
the propeller shaft to the drive shafts.
This axle is full-floating. The axle shaft is supported at
the wheel ends by the wheel hubs. The bolts that attach
the shaft to the hub, support the axle at the hub. The
splined end of the shaft is supported by the differential.
The pinion gear is supported by two tapered roller
bearings. The pinion depth is set by a shim pack between
the inner pinion bearing cup and the rear axle housing.
The pinion bearing preload is set by a shim pack at the
front of the axle housing between the bearing cone and
the pinion gear.
The ring gear is bolted onto the differential case with
right-hand thread bolts.
The differential case is supported in the case by two
tapered roller bearings. The differential and ring gear are
located in relationship to the pinion by using selective
shims between the bearings and the differential case. To
move the ring gear, shims are deleted from one side and
an equal amount are added to the other side. Differential
side bearing preload is set by the axle housing. (The axle
housing is spread to remove the differential from the
housing). When the spreader is removed, the housing
sets the bearing preload.
SECTION 4B5
DANA REAR AXLES
CONTENTS
93/4-INCH RING GEAR
DANA REAR AXLES 4B5-1
Two bearing caps are used to hold the differential into
the rear axle housing.
The differential is used to allow the wheels to turn at
different rates of speed while the rear axle continues to
transmit the driving force. This prevents tire scuffing when
going around corners and prevents premature wear on
internal axle parts.
The rear axle is sealed with a pinion seal, a hub seal,
and RTV between the differential cover and the rear axle
housing.
All Dana axles are identified by the part number on the
right axle tube next to the manufacturing date which is
next to the carrier. The model number is cast on the ear of
the carrier. The carrier cover does not have a drain plug.
CHECK THE AXLE
BEFORE DISASSEMBLY
Inspect
e
• Remove the axle cover from the rear axle and drain
the axle lubricant into a suitable container.
1. The ring g ear b ackla sh . R efer to " B a cklash
Adjustm ent" in this section. This information can be
used to determine the cause of the axle problem. It
will also help when setting up the shim packs for
locating and preloading the differential case.
2. The case for metal chips and shavings. Determine
where these chips and shavings come from, such as
a broken gear or bearing cage.
P A G E