GMC S Series 1994, Repair Manual

Page: 109 / 919

SECTION 3B2A
MANUAL STEERING GEAR
UNIT REPAIR
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 o u t
The correct torque value m ust be used when installing fasteners that require it. If the above conditions
are not followed, parts or system damage could result.
CONTENTS
SUBJECT PAGE
General D escription......................................................................................................................................................3B2A-1
Saginaw Model 535................................ ...................................................................................................................3B2A-1
S p e c ific a tio n s .................................................................................................................................................................3B2A-6
A djustm ent.................................................................................................................... ..............................................3B2A-6
Fastener Torque......................................................................................................................................................... 3B2A-6
Special T o o ls ..................................................................................................................................................................3B2A-6
GENERAL DESCRIPTION
The Saginaw steering gear is the recirculating ball nut
and worm type. The worm is located on the lower end
of the steering shaft. The ball nut is mounted on the
worm and the steel balls act as a rolling thread between
the worm and nut to provide a low friction drive
between them.
Teeth on the ball nut engage teeth on the pitman
shaft sector. The teeth on the ball nut are made so that
a tighter fit exists between the ball nut and pitman shaft
sector teeth when the front wheels are in the straight
ahead position. The sector teeth are slightly tapered so
that a proper preload may be obtained by moving the
pitman shaft endways by means of a preload adjuster
screw w hich extends through the gear housing side
cover. The head of the preload adjuster and a selective­
ly fitted shim fit snugly into a T-slot in the end of the
pitman shaft, so that the screw also controls the end
play of the shaft.
SAGINAW MODEL 5 3 5
The model 535 steering gear can be visually identi­
fied by the four-bolt side cover (figure 1). The gear has
a 28.8-mm (1.137-in.) diam eter wormshaft, and a
31.7-mm (1.25-in.) diameter pitman shaft.
For disassembly, assembly, and adjustment proce­
dures, refer to figures 2 through 4.