D6D TRACTOR POWER TRAIN – Bevel Gear And Pinion Shaft Settings (Power Shift)

Bevel Gear Shaft Preload (Power Shift)


NOTICE

Keep all parts clean from contaminants. Contaminants put into the system may cause rapid wear and shortened component life.


1. Install the bevel gear shaft without the bevel gear if the transmission is in the machine. Install the bevel gear shaft and the bevel gear if the transmission is out of the machine.

2. Install the right bearing cage (as seen from the rear of the machine) with a full package of shims. Install the bolts that hold the right bearing cage to the bevel gear case. Tighten the bolts evenly. The thickness of a full shim pack is 3.02 to 3.18 mm (.119 to .125 in.).

3. Install the left bearing cage without shims. Install four bolts without lockwashers the same distance apart that hold the bearing cage in position.

4. Tighten the bolts evenly in the left bearing cage until the end play in the bevel gear shaft is zero. Use tool (A) to measure the end play.

5. Use a feeler gauge (1) to check the distance between the flange of the bearing cage and the bevel gear case. Check the distance in four places next to the bolts around the left bearing cage. Find the average of the dimensions measured. Make a record of this dimension.

6. Remove left bearing cage.

7. Install the bearing cage with an amount of shims from another full shim pack to equal the average distance measured in Step 5 less 0.13 mm (.005 in.).

NOTE: Any time shims (2) are changed, the shaft should be turned a minimum of 50 revolutions before checking the torque needed to turn the bevel gear shaft.

8. Install the nut for the steering clutch hub on the end of the bevel gear shaft. Turn the shaft a minimum of 50 revolutions, then check the torque needed to turn the bevel gear shaft. The correct torque needed to turn the bevel gear shaft is 3.4 to 5.1 N·m (30 to 45 lb in.).


NOTICE

Perform Scheduled Oil Sampling on oil wetted compartments after performing service work to check for contaminants left in the system following repair. Contaminants put into the system may cause rapid wear and shortened component life.


Gear Clearance (Backlash) Adjustment (Power Shift)

NOTE: The steering clutches and the steering clutch hubs are removed.

1. Install a 5/8″-11 NC bolt in the hole in the transfer gear case. Tighten the bolt to a torque of not more than 7 N·m (5 lb.ft.).

NOTE: The bolt will hold the pinion shaft toward the front of the transmission so it will not turn.

2. Install tool (A) so the tip of the indicator makes contact with one of the teeth on the bevel gear.

3. Move the bevel gear backward and forward. The gear clearance (backlash) is the difference in measurements which is read on the indicator.

4. Measure the gear clearance (backlash) at four places around the bevel gear to find the smallest measurement.

5. The correct gear clearance (backlash) is 0.38 mm ± 0.10 or -0.08 mm (.015 in + .004 or – .003 in.).

6. If the smallest amount of gear clearance (backlash) is too large, remove shims from the right bearing cage and install them behind the left bearing cage. To make the gear clearance (backlash) larger, remove shims from the left bearing cage and install them behind the right bearing cage.

NOTE: The preload on the bearings for the bevel gear shaft will not change if shims are moved from one cage to the other if the thickness of shims is the same.

Location Of Bevel Pinion Shaft (Direct Drive And Special Application)

1. After the bevel gear bearing preload and gear clearance (backlash) adjustments have been made, check the tooth contact setting between the bevel gear and pinion shaft as follows:

a. Put a small amount of prussian blue, red lead or paint on the bevel gear teeth. Turn the bevel gear and check the marks made on the bevel gear teeth.

b. With no load, correct tooth settings will be shown. The area of contact starts near the toe of the gear and goes 30% up the length of the tooth. With this setting, when a load is put on the gear it will be over the correct area of the teeth.

c. If the pinion shaft is too far away from the bevel gear, short toe contact will be the result as shown. The teeth of the pinion shaft will be in contact with toe ends of convex faces (part that makes a curve toward the outside), and top edge of heel end of concave faces (part that makes a curve toward the inside). To correct this, add shims between the pinion shaft and bearing cage of the transmission. Check gear clearance (backlash) and tooth contact again.

d. If the pinion shaft is too near to the center of the bevel gear, short heel contact will be the result as shown. The teeth of the pinion shaft will be in contact with the toe ends of concave faces (part that makes a curve toward the inside) and the heel ends of convex faces (part that makes a curve toward the outside). To correct this, move the pinion shaft away from the bevel gear by addition or removal of shims between the bearing cage of the transmission and pinion shaft. After this is done, check the gear clearance (backlash) and tooth contact again.

NOTE: Several adjustments must be made for the correct tooth contact setting. If the gear clearance (backlash) is changed, the tooth contact setting will change.

2. Remove all of the prussian blue or red lead from the bevel gear and pinion shaft.

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