Dana Rear Axles; 9 3/4-Inch Ring Gear - Chevrolet 1991 Light Duty Truck Repair Manual

NOTICE: When fasteners are removed, always reinstall them at the same location from which they were
removed. If a fastener needs to be replaced, use the correct part number fastener for that application. If
the correct part number fastener is not available, a fastener of equal size and strength (or stronger) may be
used. Fasteners that are not reused, and those requiring thread locking compound will be called out. The
correct torque value must be used when installing fasteners that require it. If the above conditions are not
followed, parts or system damage could result.
SUBJECT
9 3/4-Inch Ring G ear................................................................................................................................................ 4B5- 1
D escription ............................................................................................................................................................ 4B5- 1
C hecking the Axie Before D isassem bly.......................................................................................................... 4B5- 2
D isassem bly of the Rear A x le ........................................................................................................................... 4B5- 2
Cleaning ................................................................................................................................................................. 4B5- 5
Inspection .............................................................................................................................................................. 4B5- 5
Assem bly o f the Rear A x le ................................................................................................................................ 4B5- 7
10 1/2-Inch Ring G ear.............................................................................................................................................. 4B5-14
D escription ............................................................................................................................................................4B5-14
C hecking the Axle Before D isassem bly.......................................................................................................... 4B5-14
D isassem bly o f the Rear A x le ........................................................................................................................... 4B5-14
Cleaning ................................................................................................................................................................. 4B5-18
Inspection .............................................................................................................................................................. 4B5-19
Assem bly o f the Rear A x le ................................................................................................................................ 4B5-19
S pecifications ........................................................................................................................................................... 4B5-28
Special T o ols.............................................................................................................................................................. 4B5-29
DESCRIPTION
The Dana 9 3/4-inch ring gear rear axle uses a con­
ventional ring and pinion gear set to transmit the driv­
ing 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 axle shafts.
This axle is full-floating. The axle shafts are support­
ed 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 differ­
ential.
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 bear­
ing 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 housing by
two tapered roller bearings. The differential and ring
gear are located in relationship to the pinion by using
SECTION 4B5

DANA REAR AXLES

CONTENTS

9 3/4-INCH RING GEAR

DANA REAR A XLES 4B5-1
selective shims between the bearings and the differen­
tial 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.
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.
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