DRIVE-AXLE ASSEMBLY

after replacement of parts. These are the differential

height as the preformed head. The formed head should

bearing preload adjustment (to be made first), the drive

not exceed 1/16 inch less than the preformed head as

gear and pinion backlash adjustment, and the tooth

excessive pressure will cause distortion of the case

contact adjustment. Adjust differential bearing preload

holes and result in gear eccentricity.

to be between 0.000-inches and 0.003-inch loose as

(3) Put spring thrust washers (91) and spider

follows:

pinions (92) on spider (93); replace thrust washers (90)

NOTE

and side gears (89) in case halves (87).

(4) Place spider with washers and pinions in

The latter two adjustments are so related that a

position in one case half, position other case half with

change in either one causes a change of the

side gear and washers installed, so mating marks

other adjustment.

(punched at disassembly) are aligned and install screws

(1) Install both axle housings (78 and 79) with

(88). Tighten all bolts equally and check for freedom

same thickness of gaskets (81 and 82) at each side as

from binding by turning one side gear (89) at a time

was removed at disassembly.

using an axle gearshaft (69) temporarily inserted in side

(2) Turn drive gear (85) by hand, testing for

gear splines.

noticeable drag due to trial preload condition of bearings

(5) With differential assembly installed in

(75 and 80). If no drag exists, remove axle housings,

housing, pass a three-foot long piece of rod or pipe

remove one or more gaskets (82 or 81) and repeat test

through the differential case and spider, as a handle to

until drag is noticed. Gaskets 0.005-inch thick and

aid in positioning it.

0.0075-inch thick are used. Decrease total gasket

(6) Install new gaskets (82 and 81) on studs

thickness in 0.0025-inch steps by removing two 0.005-

of differential housing (94) to total the same thickness at

inch gaskets and adding one 0.0075-inch gasket.

each side as was removed and noted at disassembly.

(3) If drag is noticeable on first trial, reverse

(7) Install differential case bearing cups (80)

procedure for decreasing gasket thickness given above

in base of housings (78 and 79). Positioning differential

until no drag is present, then decrease total gasket

with rod, install axle housings on studs of differential

thickness until drag is felt. Preload will now be between

housing. Replace nuts (70), washers '71) and alignment

0.000-inch and 0.003-inch loose, as required.

dowels (72).

(4) Install three adapter-to-axle gaskets (12,

(8) Adjust differential assembly bearing

figure 7-37) and install adapter to assembled axle.

preload (para 6-118).

(5) Remove drain plug (83, figure 7-35) from

(9) Replace pinion gear adapter (8) using

differential housing. Install plug (3/4-14 NPT threads)

attached gaskets (para 6-116). Install screws (9 and 10,

with slightly longer reach, to contact and lock bevel gear

figure 7-37), lock washer (I1, figure 7-37) and nuts (8,

(85) from rotation.

figure 7-37).

(6) Install a dial indicator on the adapter

(10) Adjust for drive gear and pinion backlash

flange, to take a reading at a tangent point 1.10-inches

and for the tooth contact pattern (para 6-1 18).

from the center of the coupling half. Rotate coupling

(11) Press bearing (68) and collar (67) onto

half through freedom permitted by pinion and ring gear

axle gearshaft (69) and install gearshaft through axle

backlash. Reading is to be 0.005-inch to 0.015-inch.

housing (79) so splines enter splines in differential side

Adjustment to correct is given in step 7. below.

NOTE

gear (89).

(12) Replace spindle (63) on housing (79),

Several adjustments of both pinion and ring

studs (77) and secure with washers (65) and nuts (64).

gear setting may be necessary in the following

(13) Replace cone and rollers (62) on spindle,

procedure before the correct adjustment is

and cup (61) in final drive gear (60). Put final drive gear

achieved. It is not possible to specify the exact

on spindle and replace cup (57), cone and rollers (56),

thickness of gaskets to be added, removed, or

washer (55), nut (54) and cotter pin (53).

exchanged at any stage This must be

(14) Using new gasket (66) and oil seal (59),

determined by trial and error.

install final drive gear case (58) (with brake assembly

(7) Apply a thin coating of red lead to drive

attached) on axle housing.

face of ring gear teeth, and reinstall adapter to axle,

(15) Replace front wheel, hubcap, and brake

adding gaskets (12, figure 7-37) to increase backlash, or

lines and fittings.

using fewer gaskets to decrease backlash.

6-118. ADJUSTMENTS. Three basic adjustments are

to be made when the differential has been reassembled

6-33