GMC S Series 1994, Repair Manual

Page: 204 / 919

CONTENTS (cont’d)
SUBJECT PAGE
Drive Axle A s s e m b ly ................................................................................................................................................... 4C1-17
Outer Deflector R in g ................................................................................................................................................ 4C1-17
ABS Sensor Ring.......................................................................................................................................................4C1-17
Outer Joint S e a l......................................................................................................................................................... 4C1-17
Outer Joint A ssem b ly.............................................................................................................................................. 4C1-21
Inner Tripot S e a l........................................................................................................................................................ 4C1-22
S p ecificatio n s.................................................................................................................................................................4C1-24
Fastener Tightening Specifications......................................................................................................................4C1-24
Available Shim S izes................................................................................................................................................ 4C1-24
Pinion Preload and B a c k la s h ................................................................................................................................4C1-24
Lubrication................................................................................................................................................................... 4C1 -24
Special T o o ls .................................................................................................................................................................. 4C1-25
GENERAL DESCRIPTION
The axle used on T model vehicles has a center
disconnect feature which allows shifting into and out of
four wheel drive when the vehicle is in motion under
most conditions.
The axle uses a conventional ring and pinion gear set
to transmit the driving force of the engine to the wheels.
The gear set transfers the driving force at a 90-degree
angle from the propeller shaft to the axle shafts.
The pinion gear is supported by two tapered roller
bearings. The pinion depth is set by a shim pack locat­
ed between the gear end of the pinion and the roller
bearing that is pressed onto the pinion. The pinion
bearing preload is set by crushing a collapsible spacer
between the pinion bearings in the axle housing.
The ring gear is bolted to the differential case with
left-hand thread bolts.
The differential case is supported in the axle housing
by two tapered roller bearings. The differential and ring
gear are located in relationship to the pinion by thread­
ed adjusters.
The differential allows the wheels to turn at different
rates of speed while the front axle continues to transmit
the driving force. This prevents tire scuffing while turn­
ing and premature wear on internal axle parts.
The alphabetic identification code is located on a tag
attached to the right axle tube.
DISASSEMBLY
IN SPEC TIO N
Perform the following checks before disassembling
the axle.
1. Remove the axle cover and drain the lubricant.
2. Check the ring gear backlash. Refer to “ Backlash
A djustm ent.” This inform ation can be used to
determine the cause of the axle problem. It will
OF THE AXLE
also help when setting up the shim packs for locat­
ing and preloading the differential case.
3. Inspect the case and oil for metal chips. Determine
where the metal chips came from, such as a bro­
ken gear or bearing cage.
4. Determine the cause of the axle problem before
disassembly, if possible.