DIFFERENTIAL ADJUSTMENTS.

TM 10-3930-623-34

adjustments require that the same transmission to be

2. Turn output gearshaft (66, figure 4-14) so

installed with the axle be used in making the

screws (52) are in vertical alignment, and offset flats on

adjustments.

Before beginning assembly have this

circumference of output shaft keeper (51) will be

transmission available with one set of gaskets (14 and

horizontal.

18, figure 4-11) to provide a difference between the

bearing cone end and the gasket pack of 0.119 inch to

3. Mount a dial indicator on access hole of

0.125 inch. Add or remove gaskets as required to obtain

transmission to contact downward facing flat on the

required bearing exposure. Proceed as follows with

keeper, at a point one inch from center line of shaft.

assembly and adjustment.

4. Through hole in differential housing from which

1. Rivet ring gear (72, figure 4-12) to case (65)

pipe plug was removed, insert rod, or long pipe plug to

half. Press one bearing cone and roller (64) onto

hold ring gear locked.

trunnion of each case half. Place a thrust washer (68)

and side gear (67) in place in each case half.

5. Turn output gearshaft in both directions through

backlash freedom, noting reading on dial indicator

2. Put four spider gears (70) and thrust washers

Reading of 0.007 inch to 0.017 inch is satisfactory.

(69) on spider (71) and install in one case half. Align

Adjustments to correct backlash art given in paragraph

match marks on case halves and assemble case halves

6-61.

with screws (66). Install cups (60) in axle housings (61)

and put a set of gaskets (62 and 63) on studs (59) of

6. Reverse steps (1) through (4) if no adjustment is

differential housing (76). Use same thickness of gaskets

to be made.

at each side as was removed at disassembly for initial

assembly.

6-63.

DIFFERENTIAL

TOOTH

CONTACT

Adjust ring gear and pinion tooth

ADJUSTMENT.

3. Position assembled differential in housing (76).

contact, after adjusting backlash, as follows:

Differential will be loose. Pass a piece of rod or tubing

about three feet long through differential center to aid

NOTE

manipulation during assembly. Position axle housings

Several adjustments of both pinion

(61) on differential housing studs.

Place tapered

and ring gear setting may be

bushings (58) on studs and install nuts (55) and washers

necessary in the following procedure

(56 and 57).

before the correct adjustment is

achieved. It is not possible to specify

4. Turn ring gear by hand, testing for noticeable

the exact thickness of gaskets to be

drag due to preload condition of differential bearings. If

added, removed, or exchanged at any

no drag exists, remove gaskets (62 or 63) and repeat

stage. This is determined by trial and

test until drag is noticed. Gasket (62) is 0.005 inch thick,

error.

and gasket (63) is 0.0075 inch thick. Decrease total

gasket thickness in 0.0025 inch steps by removing two

1. Apply a thin coating of red lead to drive face of

0.005 inch gaskets and adding one 0.0075 inch gasket.

ring gear teeth, and install axle on transmission with

gaskets used in paragraph 6-62, step 1.

5. If drag is noticeable on first trial, reverse

procedure for decreasing gasket thickness in stop 4

2. Remove access plate (5, figure 4-14) from

above until no drag is present, then decrease total

bottom of transmission.

gasket thickness until drag is felt. Preload will now be

between 0.000 inch and 0.003 inch.

3. Engage spur gear (68) with a pry bar, and turn it

until differential has made one revolution in the forward

6. Press bearings (54) and retainers (53) onto axle

direction.

shafts. Positioning differential with rod (see step 3

above), enter splines of one axle shaft into side gear

4. Remove transmission from axle. Examine teeth

(67) and install bearing retainer (49). Steady differential

of ring gear, and compare marks in red lead from pinion

assembly by hand and repeat installation for other axle

gear contact with examples shown in figure 6-9.

shaft.

NOTE

7. Check pinion and ring gear backlash adjustment

Ring gear is on left side of pinion

as follows, before assembling axle reduction ends to

when installed. References to follow

differential section of the axle.

will be on this basis.

5. If marks in red lead compare with those sho wn

6-62. DIFFERENTIAL ADJUSTMENTS.

in view A, figure 6-9, indicating high, narrow tooth

1. Temporarily assemble drive axle and gaskets

contact (pinion too far out), adjust by removing one or

(14 and 18, figure 4-1) to transmission. Remove access

more gaskets (I4 or 18, figure 4-11) to move pinion in

plate (5 figure 4-14) at bottom of transmission and

direction indicated in box adjacent to view A, figure 6-9.

remove pip4 plug (75, figure 4-12) from bottom of

Transfer one or more gaskets (62 or 63, figure 4-12)

differential housing (76).

from left side of differential housing to right side. Repeat

steps (1) through (4) above to check results of

adjustment.

6-15