Skip to: site menu | section menu | main content
STEERING GEAR ASSEMBLY
Construction
The steering gear used in the Master models
passenger cars with
knee action is of the ball bearing roller sector type with an hour
glass worm and with a gear ratio of 16 to 1.
Fig. 214— Steering Gear Assembly — Knee Action Cars
In this type of steering gear, the worm is rotated as usual, by
movement of the steering wheel at the upper end of the worm or
main shaft.
The sector has the tooth contours turned annularly around its entire
circumference, like a roller. In addition to acting as sector teeth,
this roller forms the outer race for a two-row ball bearing.
The inner race of this double-row bearing is made in two halves,
one assembly forming each end and held together by a snap ring
at the middle. This bearing is pre-loaded to prolong its useful
life.
The combined ball bearing and roller sector is pivoted on a hardened
and ground bolt in jaws at the inner end of the pitman arm shaft.
This jaw is forged integral at an angle normal to the worm centerline.
A slightly tight fit is provided through the central range of the
worm movement, where most wear occurs, to increase the life of
the gears.
The pitman arm shaft bears in two long babbit bearings having oil
grooves. The upper roller bearing on the worm, is mounted in the
adjusting sleeve insuring accurate alignment.
Bolts passing through the frame side rail and sub-frame secure
the steering gear housing rigidly to the frame.
The steering gear used in the Master Conventional,
1/2 ton and 1 1/2-ton trucks and the Standard passenger cars is
of the worm and sector type with a gear ratio of 14 to 1.
The worm and inner cones for the roller bearings are machined in
one piece from solid stock, properly heat treated to give long
life. This design insures the worm being always true with its bearings
assuring a free steering gear without binding or tight spots.
Fig. 215— Steering Gear Assembly — Master Conventional,
1- Ton and 1½-Ton Trucks and Standard Models
The sector and shaft is a one-piece forging accurately machined,
heat treated for strength and finely ground. A feature of this
design of the sector teeth, is that in the straight ahead position
all back lash between the gears is automatically reduced, but on
curves a few thousands of play is allowed for ease of handling.
