Main drive bevel gears and differential


The differential is carried on tapered roller bearings. The bearing on the bevel gear side of the differential is larger than that on the opposite side and therefore, it is necessary to keep the bearing cages in the proper relationship.
The differential assembly for Tractor models has two pinions with a single cross shaft. Tractors have four pinions and four stud shafts. The differential lock is on the right side of tractors.
The bevel drive pinion is the range tractor transmission mainshaft. On two-wheel drive tractor models, the light duty park brake drum is on the bevel drive pinion shaft. On two-wheel drive and four-wheel drive tractor models, the heavy duty park brake drum is the flange on left side of bevel ring gear.

OVERHAUL DIFFERENTIAL

To remove the differential assembly, first remove cab or fenders, fuel tank and seat platform. Remove hydraulic lift housing and final drives. Disconnect and remove bevel pinion and ring gear lubrication tube. Disconnect and remove differential lock shaft and fork. On models so equipped, disconnect and remove heavy duty park brake cam pivot and brake band hanger support. On all models, remove inner brake ring from each side. Using special tool and a slide hammer, pull out brake pistons. Install a rope through differential carrier for a sling and attach it to a hoist. Support differential with the hoist and unbolt and remove bearing housings (18 and 22) and shims (21). Identify and keep shims with their relevant bearing housing. Remove differential and heavy duty park brake band, if so equipped. Slip off the brake band.
Remove bolts (3 and 4) and separate bevel ring gear (6) from differential carrier (11). Remove thrust washer (7).

Differential assembly

1. Bearing cup, (L.H.), 2. Bearing cone,(L.H.), 3. Dowel bolt, 4. Bolt , 5. Bevel pinion shaft, 6. Bevel ring gear, 7. Thrust washer, 8. Side gears, 9. Differential pinions, 10. Stub shafts, 11. Differential carrier, 12. Cross shaft, 13.Spring (2), 14.Differential lock ring, 15.Bearing cone,(R.H.), 16.Bearing cup,(R.H.), 17.Cap screws, 18.Bearing housing,(R.H.), 19."O" rings, 20."O" rings, 21.Shims, 22.Bearing housing,(L.H.)

The four dowel bolts (3) secure the four stub shafts (10). On some tractors, single cross shaft (12) and two pinions (9) are used.
Remove stub shafts (10) or cross shaft (12), then remove side gears (8) and differential pinions (9). Using a suitable puller, remove bearing cones (2 and 15). Remove differential lock ring (14) and springs (13). If necessary, remove bearing cups (1 and 16) from bearing housings (18 and 22).
Clean and inspect all parts and renew any showing excessive wear or other damage. If bevel ring gear is to be renewed, bevel pinion shaft (5) must also be renewed as they are available only as a matched set. To  install and position adjustment of the bevel pinion shaft. Reassemble by reversing the disassembly procedure keeping the following points in mind: Thrust washer (7) has a lug which locates in a hole in bevel ring gear. Use petroleum jelly to stick thrust washer in ring gear for aid in installation to differential carrier. Use Loctite 241 on threads of bolts (3 and 4) and tighten bolts to a torque of 115-130 ft.-lbs. (156-176 N-m). Reinstall differential and adjust carrier bearing preload as follows: 
Install right bearing housing (18) without shims (21) and "0" rings (19 and 20). Tighten cap screws (17) evenly to a torque of 115-130 ft.-Ibs. (156-176 N-m). Install left bearing housing (22) without "O" rings (19 and 20) but with all shims (21) removed from right and left sides. 

Tighten left side cap screws (17) evenly until a slight amount of end play can be felt at ring gear. Remove sling and hoist from differential. Rotate differential several turns to make sure carrier bearings are seated. Wind a cord around the differential lock ring (14) and connect a spring scale to end of cord. Make certain that range gears are in neutral position. Pull the spring scale and note the amount of pull required to rotate the differential assembly. Then, continue tightening left side cap screws evenly to a torque of 115-130 ft.-lbs. (156-176 N-m), Again, using the spring scale and cord, check amount of pull needed to rotate the differential assembly. The bearing preload is correct when a rolling pull on scale is 4.5-14.5 lbs. (2.0-6.5 kg). Add or remove shims as required to obtain correct amount of pull. One shim thickness of 0.001 inch (0.025 mm) will change amount of pull 1.0 lb. (0.64 kg). Shims are available in thicknesses of 0.003, 0.007, 0.012 and 0.030 inch (0.076, 0.170, 0.300 and 0.760 mm).

Always support the differential assembly when removing the bearing housings.
With bearing preload set, adjust bevel gear backlash as follows: 
Support differential assembly and remove bearing housings (18 and 22). Divide the shims and install half on each bearing housing. Install right bearing housing (18) and tighten cap screws to a torque of 115-130 ft.-lbs. (156-176 N-m). Install left bearing housing (22) and tighten left side cap screws to a torque of 115-130 ft.-lbs. (156-176 N-m). Make sure some backlash exists between bevel ring gear (6) and bevel drive pinion (5). Using a dial indicator, check backlash. Backlash should be 0.006-0.012 inch (0.15-0.30 mm). Check backlash every 90 degrees of ring gear. Backlash must not vary more than 0.004 inch (0.1 mm) during the four readings, To increase backlash, remove shims from right side and install on left side. To decrease backlash, remove shims from left side and install on right side. Do not change total number of shims as this will affect bearing preload. Shim pack thickness must not be more than 0,071 inch (1.80 mm) on either side.
With bearing preload and backlash adjusted, remove bearing housings and install new "O" rings (19 and 20). Lubricate "O" rings with petroleum jelly. Apply Loctite 241 to bearing housing cap screws (17), then tighten cap screws to a torque of 115-130 ft.-lbs. (156-176 N-m).
Lubricate new "O" rings with petroleum jelly and install on brake pistons. Install brake pistons, then install brake inner rings. The balance of reassembly is the reverse of disassembly procedures.

DIFFERENTIAL LOCK

Tractors are equipped with a differential lock which operates on the right side of the differential with a dowel pin type coupling locking the differential gears. It is operated with a pedal on right side of tractor.
Refer to Figure for an exploded view of differential lock linkage and to items (13 and 14) for differential lock.

Differential lock

OVERHAUL. Removal and overhaul of the differential lock requires removal and separation of the differential assembly. Overhaul of the differential lock is obvious after examination of the unit, to adjust the linkage and disconnect link (9). Rotate shaft and lever (12) forward until fork (17) is fully bottomed on actuating pin (16). At this time differential lock should be fully engaged. Rotate lever and shaft (12) rearward until differential lock is fully disengaged. With pedal up, adjust length of adjusting link (9) until link will align with hole in lever. Reconnect link and actuate pedal to see that differential lock will engage and disengage properly. Adjust nuts (1), if necessary, to make sure spring (3) fully raises pedal to disengaged position. Overall length of adjusted spring (3) should be approximately 9 inches (229 mm).

PARK BRAKE

A light duty park brake is used on tractors equipped with two-wheel drive. Park brake drum is located on the bevel drive pinion (range transmission mainshaft).
A heavy duty park brake is used on tractors equipped with two-wheel drive and four-wheel drive. The park brake drum is the flange on the bevel ring gear.
To adjust the light duty park brake, refer to Figure and turn adjusting nut clockwise, as viewed from front, until a pull of 10 lbs. (44.48 N) will apply park brake two or three notches on the ratchet. A pull of 10 lbs. (44.48 N) must not pull the lever past the fourth notch. When no further adjustment can be made at the adjusting nut, a new brake band must be installed.
To adjust the heavy duty park brake and loosen locknut on lower clevis. Disconnect lower clevis from actuating arm. Rotate the clevis to adjust the rod length. Shorten the rod length to tighten the brake. Reconnect linkage and check park brake engagement. A pull of 70 lbs. (311 N) must not pull brake hand lever past the fourth notch on ratchet. When no further adjustment can be made on clevis, a new brake band must be installed.

Adjustment point on light duty park brake linkage

Adjustment point on heavy duty park brake linkage

On tractor models, place hand lever so the pawl is engaged in the first notch on ratchet. Adjust nuts on brake warning light switch so that the switch plunger is just in contact with park brake handle. Move park brake handle fully downward (disengaged position. Switch plunger should be pushed in 0.216-0.275 inch (5-7 mm) and brake warning light must be off.