Cleaning, Inspection and Repair. - TM-10-3930-624-340065

(4) Press the front bearing cup (11) and the

(6) Remove the gasket (16) from the face of

rear bearing cup (15) into the carrier (17). Ensure

the carrier (17).

that the cups are fully seated.

(7) Remove the adjusting nut (18). Pull the

(5) Place the carrier housing in a preload

bearing (19) and drive off the bearing cup (20).

fixture to determine the necessary preload shims.

(8) Remove the lockwire (21) and capscrews

Set the shims and spacer aside for use in final

(22). Separate the plain case half (23) from the

assembly.

flange case half (24). Note aligning marks on the

(6) Press the front bearing (12) onto the

case halves.

pinion (8) and place in the carrier. Install the rear

(9) Remove the thrust washers (25 and 26),

bearing (14), pinion flange (6) and flange nut (5).

side gears (27), spider gears (28) and spider (29).

Do not install shims or spacer at this time. Tighten

(10) Cut the lockwire and remove the cap-

the nut to a torque of 15 to 25 in. lbs. Spin the

screws (30). Using a brass drift, drive out the

pinion to the right and left at least six times and

dowels (31) and remove the ring gear (32).

c. Cleaning, Inspection and Repair.

check the torque.

(7) Place the carrier housing so that the open

(1) Clean all components except bearings in

solvent and dry with compressed air. Clean

end is up, and install a side bearing bore arbor tool.

Do not install the caps.

bearings as instructed in paragraph 2-7.

(8) Insert a feeler gage between the top of the

(2) Inspect gears for chipped, cracked, broken

pinion and the bottom of the arbor. The gage

or worn teeth. Check machined surfaces for nicks,

reading, plus or minus the value etched on the

scratches, scoring, pitting a n d o t h e r s u r f a c e

damage. R e m o v e b u r r s a n d minor surface

pinion head is the shim pack dimension. For

example, if the pinion is etched +0.003, subtract

blemishes with a soft hone or crocus cloth. Inspect

0.003 from the feeler gage reading. If the pinion is

the bores for worn or out-of-round condition.

etched -0.003, add 0.003 to the reading. Thus, if

Replace gears if excessively worn.

the feeler gage reading is 0.020 and the pinion is

Note. The ring gear and pinion must be replaced as a

etched + 0.003, the shim pack would be 0.017.

set.

(9) Remove the flange nut (5), pinion flange

(3) Inspect the bearings for nicks, scratches,

(6), rear bearing (14), pinion (8) and front bearing

scoring and pitting of the bearing surfaces. Replace

(12).

damaged bearings.

(10) Install the shim pack under the head of

(4) Inspect the pinion for chipped or broken

the pinion (8) and press on the bearing (12). Install

teeth. Inspect the splines and all machined surfaces

the spacer and shims determined in step (5) above.

for nicks, scratches, scoring, pitting and other

Install the cup (13) and seal (7) and install the

damage. Smooth surfaces with a soft hone or crocus

pinion in the carrier. Install the rear bearing (14),

cloth. Replace pinion and ring gear if damage or

pinion flange (6) and flange nut (5). Tighten the

wear is excessive.

nut to a torque of 15 to 25 in. lbs. and secure with

(5) Inspect cases and carrier for cracks,

the cotter pin (4).

breaks, fatigue lines, and damage to machined

(11) Install a new gasket (16).

surfaces. Remove minor surface blemishes with a

(12) Install the differential assembly, engaging

soft hone or crocus cloth. Repair damage if possible

the ring gear with the pinion. Coat the ring gear

or replace as required.

(32) with white lead or Prussian blue to obtain a

(6) Inspect bearing cups and cones for nicks,

tooth pattern. Install the bearing caps (3) but do

scratches, burrs, scoring, pitting and wear. Replace

not tighten the capscrews (1).

cups and cones as assemblies as required.

(13) Using a dial indicator, adjust the ring

(7) Inspect all other components for damage

gear laterally for a backlash of 0.005 to 0.010. To

and wear. Replace parts as necessary.

increase backlash, loosen the adjusting nut (18)

d. Reassembly. (fig. 4-15.)

nearest the ring gear and tighten the opposite nut.

(1) Position two dowels (31) in the ring gear

To decrease backlash, reverse the operation.

(32) and align the ring gear with dowel holes in the

(14) When backlash is properly adjusted,

flange case (24). Install the capscrews (30) and

rotate the pinion and hold back on the ring gear to

tighten to draw the ring gear into place. Tighten the

simulate a load. Rotate the pinion several turns and

capscrews and secure with lockwire.

inspect the teeth of the pinion for the ring gear

(2) Place the thrust washer (25) in the bottom

contact pattern. The contact should start at a point

of the flanged case 124). Install the side gear (27),

1/32 to 1/16 inch from the top of the tooth and

spider (29), spider gears (28), thrust washers (26),

continue downward to a point 1/32 to 1/16 inch

side gear (27) and thrust washer (25).

from the bottom of the tooth. Refer to pattern A in

(3) Install the plain case half (23) and secure

figure 4-16. Patterns B through E show improper

with capscrews (22) and lockwire (21).

wear as follows:

4-15