Cleaning and Inspection.

TM 10-3930-633-34

(1) Split metal bushings with hacksaw and

(5) Pull off brake drum with bearing cups (24

drive bushings from knuckle.

and 26), cone (27) and seal (28).

(2) Remove nicks and burrs from knuckle

(6) Remove brake assemblies from steering

bushing bore and polish with medium grit

knuckles.

abrasive.

(7) Remove nuts (16), cotter pins (17) and

(3) Apply chassis lube to bushings and

steering arms (14 and 13).

knuckle bore and install bushings.

(8) Drive out draw keys (33 and 34) from the

f. Reassembly.

small end. Remove expansion plugs (32 ) and drive

(1) Make certain that the knuckle pin hole in

out knuckles pins (35), to free knuckles (42 and

the axle center is clean and dry.

43), shims (39) and bearings (40) from axle beam

(2) Position and support the steering knuckle

(44).

assembly (41 or 42, fig. 12-2) on the axle center

c. Cleaning and Inspection.

(43).

(1) Clean parts having ground and polished

(3) Slide the thrust bearing (40) between the

surfaces, such as knuckle pins, knuckle pin

lower face of the axle center and the lower steering

sleeves, bearings and spindles, with solvent,

knuckle yoke.

Federal Specification P-D-680. Do not clean these

NOTE

parts in a hot solution tank or with water and

Thrust bearings that are not marked "TOP" to in-

alkaline solutions such as sodium hydroxide,

dicate proper installation orientation must be

orthosilicates or phosphates.

positioned with retainer lip down.

(2) Parts should be thoroughly dried im-

(4) Align the steering knuckle yoke holes

mediately after cleaning. Use soft, clean, lintless,

with axle center and thrust bearing bores.

absorbent paper towels or wiping rags free of

(5) Place a jack under the lower side of

abrasive material, such as lapping compound,

steering knuckle yoke and raise knuckle so that

metal filings or contaminated oil. Bearings should

all clearance is taken up between lower yoke,

never be dried by spinning with compressed air.

thrust bearing (40) and lower face of axle center

(3) Inspect the steering knuckle thrust

end.

bearing, wheel bearing cones and cups. Replace if

(6) Check the clearance between the top face

rollers or cups are worn, pitted or damaged in any

of upper axle center end and lower face of upper

way. If wheel bearing cups are to be replaced,

knuckle pin boss. The clearance must not exceed

remove from hubs with a suitable puller. Avoid

.005 inches. Washers and shims (39) are available

the use of drift and hammers as they may easily

in various thicknesses to take up this clearance

mutilate cup bores.

and hold it within the desired .005 inch tolerance.

(4) Inspect the steering knuckles and replace

(7) Align flats on knuckle pin (35) with the

if indications of weakness or excessive wear is

centerline of the draw key holes. Drive knuckle

found.

pin (35) through knuckle yoke, axle center and

(5) Check wear of the knuckle pins and

thrust bearing, working from top of axle.

bushings. Compare with new part dimensions to

(8) Install the draw keys (33) into the axle

determine extent of wear.

center. Drive the draw key in so that the flat on

d. Repair.

the key will mate with the corresponding flats on

(1) Repair generally consists of replacement

the knuckle pin. Seat pin firmly in place.

of defective parts.

(9) Install expansion plugs (32) in knuckle

(2) Straightening of bent parts should be

bores, top and bottom.

done cold. Various components are heat-treated

(10) Reinstall backing plates and brake

and hot straightening would destroy some of the

assemblies, if previously removed. Also, if axle

heat treatment.

assembly was removed from truck chassis,

(3) Axle centers (that are bent no more than

reinstall at this time.

inch) may be straightened cold; if bent more

(11 ) Install tie rod as outlined in Chapter 11.

than inch, they should be replaced.

(12) Install brake drum and hubs with

(4) Bent steering arms or knuckles should be

bearings in place and properly lubricated ac-

replaced rather than straightened.

cording to instructions in TM 10-3930-633-12.

e. Replacement of Knuckle Bushings. Nylon

(13) Axle is ready for installation.

bushings are used on production axles and are

g. Installation.

also used as a replacement for axles having the

(1) Refer to Chapter 2, Section IV, for in-

bronze type bushing. For installing nylon

replacement, proceed as follows:

12-3