Assembly.

(i) Insert rack-piston arbor tool into worm.

problem if it lies in the steering gear adjustments. If not,

check the rack-piston nut and worm for excessive lash

Turn rack-piston onto the arbor. Do not allow arbor to

or excessive load overcenter and also for roughness at

separate from worm until rack-piston nut is fully on

any point along the worm. If any of these conditions are

arbor.

found, disassemble and inspect worm and rack-piston

(5) Installation.

nut grooves and all the balls for excessive wear or

(a) Assemble thrust bearing (25) and races

scoring.

If either worm or rack-piston nut need

(16) on worm (17). Assemble valve assembly to worm

replacing, both must be replaced as a matched

by aligning small slot in valve body (21) with pin on

assembly. The lash or heavy load may be corrected by

worm. Be sure to install packing (18) between body and

replacing the standard balls with a larger or smaller size-

worm head.

black balls need not be replaced unless they are

(b) Install valve assembly and worm in

defective.

In case the black balls cannot be

housing (46) as integral unit and continue valve

distinguished from the standard balls, replace with new

assembly as outlined in f. (4) above. Adjust thrust

balls.

bearings (see g. below).

(e) Inspect ball return guides (43), making

sure that the ends where the balls enter and leave the

for tool details) in gear housing (46, fig. 11-2). Hold it

guides are not damaged.

tight against shoulder in housing. Insert rack-piston nut

(f) Inspect lower thrust bearing (25) and

(35) into housing until arbor engages worm. Turn stub

races (16).

shaft (20) clockwise, drawing rack-piston nut into the

(g) Inspect rack-piston nut (35) teeth for wear

housing. When piston ring is in housing bore, withdraw

and chipping. Inspect rack-piston nut surface for scoring

arbor from rack-piston nut. Remove ring compressor.

or burrs.

(d) Install rack-piston plug as outlined in e.

(4) Assembly.

above.

(a) Thoroughly clean the parts and lubricate

(e) Install housing end plug as outlined in d.

the internal parts with automatic transmission fluid, Type

above.

"A".

(f) Install sector gearshaft and side cover as

(b) Drive new connectors (14 and 15) in place

outlined in c. above.

with piloted driver.

g. Thrust Bearing Adjustment, After Assembly.

Note. This adjustment is to be made

automatic transmission fluid, Type "A". Assemble in

after the worm, thurst bearings, valve

piston ring groove on rack-piston nut (35). Install new

assembly, adjuster plug assembly,

piston ring (37) in the ring groove over the packing by

and lock nut are assembled in the

carefully slipping ring over the rackpiston nut. The ring

housing assembly.

Proceed as

may be slightly loose after assembly. This is normal. It

follows:

will tighten when subjected to the hot oil in the system.

(1) Before adjusting preload, tighten adjuster plug

(d) Insert worm (17) into rack-piston nut, to

(61) up snug, back off slightly (1/8 turn) and measure

bearing shoulder.

valve assembly drag.

(e) Align the ball return guide holes with the

(2) Turn adjuster plug in so that preload is 1 to 3

worm groove. Load 24 balls (42) into the guide hole

inch pounds more than valve assembly drag. Tighten

nearest the piston ring, while slowly rotating the worm

lock nut (3). Total thrust bearing adjustment and seal

(17) counterclockwise to feed the balls through the

drag is not to exceed 8 inch pounds.

circuit. Alternate the black balls with the standard balls.

h. Overcenter or Sector Gearshaft Adjustment After

(f) Fill one of ball return guides with

Assembly.

remaining six balls. Place other guide over balls and

Note. This adjustment is to be made

plug ends with grease, automotive and artillery, MIL-G-

after

the

gear

completely

10924, to prevent balls falling out when installing guide

assembled.

into rack-piston nut.

(1) With gear on center and lash adjuster backed

(g) Insert guides into guide holes of rack-

off, measure total drag.

piston nut. Guides should fit loosely.

(2) With gear on center, adjust lash adjuster so

(h) Place return guide clamp over guides,

that preload is 4 to 8 inch pounds in excess of total

install two screws and lock washers and tighten to 8 to

preload and drag. Readings are to be made through an

12 foot pounds.

arc not exceeding 20 degrees with gear on center.

(3) Tighten lash adjuster lock nut.

11-7