Pinion gear depth

GENERAL INFORMATION

Ring gear and pinion are supplied as matched sets only. The identifying numbers for the ring gear and pinion are painted onto the pinion gear shaft (Fig.

36) and the side of the ring gear. A plus (+) number, minus (-) number or zero (0) along with the gear set sequence number (01 to 99) is on each gear. This first number is the amount (in thousandths of an inch) the depth varies from the standard depth setting of a pinion marked with a (0). The next two numbers are the sequence number of the gear set. The standard setting from the center line of the ring gear to the back face of the pinion is 99.690 mm (3.925 in.). The standard depth provides the best teeth contact pattern.

Refer to Backlash and Contact Pattern Analysis Paragraph in this section for additional information.

Fig. 36 Pinion ID Numbers

1 - VARIANCE NUMBER

2 - SEQUENCE NUMBER

Compensation for pinion depth variance is achieved with select shims. The shims are placed between the rear pinion bearing cone and the pinion gear head (Fig. 37).

If a new gear set is being installed, note the depth variance marked on both the original and replacement pinion. Add or subtract the thickness of the original depth shims to compensate for the difference in the depth variances. Refer to the Depth Variance charts.

Note where Old and New Pinion Marking columns intersect. Intersecting figure represents plus or minus amount needed.

Note the painted number on the shaft of the drive pinion (-1, -2, 0, +1, +2, etc.). The numbers represent thousands of an inch deviation from the standard.

If the number is negative, add that value to the required thickness of the depth shim(s). If the number is positive, subtract that value from the thickness of the depth shim(s). If the number is 0 no change is necessary. Refer to the Pinion Gear Depth Variance Chart.

Fig. 37 Shim Locations

1 - PINION GEAR DEPTH SHIM

2 - DIFFERENTIAL BEARING SHIM-PINION GEAR SIDE

3 - RING GEAR

4 - DIFFERENTIAL BEARING SHIM-RING GEAR SIDE

5 - COLLAPSIBLE SPACER

PINION DEPTH MEASUREMENT AND ADJUSTMENT

Measurements are taken with pinion cups and pinion bearings installed in housing. Take measurements with a Pinion Gauge Set, Pinion Block 8177, Arbor Discs 8541, and Dial Indicator C-3339 (Fig.

38).

(1) Assemble Pinion Height Block 6739, Pinion Block 8177, and rear pinion bearing onto Screw 6741 (Fig. 38).

(2) Insert assembled height gauge components, rear bearing and screw into axle housing through the pinion bearing cups (Fig. 39).

(3) Install front pinion bearing and Cone 6740 onto the screw hand tight (Fig. 38).

PINION GEAR DEPTH VARIANCE

Fig. 38 Pinion Gear Depth Gauge Tools

1 - DIAL INDICATOR

2 - ARBOR

3 - PINION HEIGHT BLOCK

4 - CONE

5 - SCREW

6 - PINION BLOCK

7 - SCOOTER BLOCK

8 - ARBOR DISC

(4) Place Arbor Discs 8541 on Arbor D-115-3 in position in axle housing side bearing cradles (Fig.

40). Install differential bearing caps on Arbor Discs and tighten cap bolts. Refer to the Torque Specifications in this section.

Fig. 39 Pinion Height Block

1 - PINION BLOCK

2 - PINION HEIGHT BLOCK

(5) Assemble Dial Indicator C-3339 into Scooter Block D-115-2 and secure set screw.

(6) Place Scooter Block/Dial Indicator in position in axle housing so dial probe and scooter block are flush against the surface of the pinion height block.

Hold scooter block in place and zero the dial indicator face to the pointer. Tighten dial indicator face lock screw.

(7) With scooter block still in position against the pinion height block, slowly slide the dial indicator probe over the edge of the pinion height block.

Observe how many revolutions counterclockwise the dial pointer travels (approximately 0.125 in.) to the out-stop of the dial indicator.

(8) Slide the dial indicator probe across the gap between the pinion height block and the arbor bar with the scooter block against the pinion height block (Fig. 41). When the dial probe contacts the arbor bar, the dial pointer will turn clockwise. Bring dial pointer back to zero against the arbor bar, do not turn dial face. Continue moving the dial probe to the crest of the arbor bar and record the highest reading.

If the dial indicator can not achieve the zero reading, the rear bearing cup or the pinion depth gauge set is not installed correctly.

(9) Select a shim equal to the dial indicator reading plus the drive pinion gear depth variance number marked on the shaft of the pinion gear using the opposite sign on the variance number. For example, if the depth variance is -2, add +0.002 in. to the dial indicator reading.

(10) Remove the pinion depth gauge components from the axle housing

Fig. 40 Gauge Tools In Housing