Pinion Depth Adjustment

Fig. 24 Pinion Depth Gauge Assembly:

Fig. 25 Pinion Depth Gauge Assembly:

Fig. 26 Pinion Depth Gauge Tool Installation:

If original ring gear and pinion, rear pinion bearing and housing are reused, original pinion depth adjusting shims can be reused to adjust pinion depth. However, if gear set, rear pinion bearing or housing are replaced, pinion depth adjusting shims must be selected in order to establish proper ring gear and pinion tooth contact. Several types of pinion depth gauging tools are available from a variety of manufacturers, and manufacturer's recommendations as to component selection and installation must be followed when using any depth gauging assembly. Procedures outlined use gauge tool set No. D-116, or equivalent, or set No. 6730 and dial indicator tool No. C-3339, or equivalents. If no pinion depth gauge is available, preliminary shims can be selected as outlined, and final shim selection can be determined by performing gear tooth contact inspection outlined under "Final Assembly and Adjustment."

PRELIMINARY SHIM SELECTION

Fig. 27 Pinion Depth Modification Code Identification:

1. Inspect face of both new and old drive pinion for pinion depth modification code. To ensure proper contact of ring gear and pinion teeth, pinion may be marked with a plus (+) or minus (-) code number. This number indicates in thousandths of an inch necessary modifications of nominal pinion depth. It is essential that this code number be factored when selecting pinion depth adjusting shims.
2. Measure thickness of shim pack removed from behind rear pinion bearing race and record thickness.

Fig. 28 Preliminary Pinion Depth Adjusting Shim Selection Chart:

3. Refer to chart, and select preliminary shim pack thickness by adding or subtracting indicated value from thickness of original shims. If baffle is installed in assembly, thickness of baffle must be included in shim pack.
4. Install selected shim pack behind rear pinion race as outlined in assembly procedures, then perform tooth contact inspection.
5. Adjust pinion shim thickness as needed, to obtain proper tooth contact.

SHIM SELECTION USING DEPTH GAUGE

Fig. 29 Pinion Block Installation (typical):

1. Install master pinion block into pinion bore in housing.
2. Install side bearing discs on arbor, then mount arbor assembly in housing ensuring arbor is centered and discs are seated in bearing bores.

Fig. 30 Height Block & Dial Indicator Installation (typical):

3. Position pinion height block on pinion block and against arbor.
4. Install gauge block and dial indicator on small step of pinion height block, ensuring gauge assembly is flat on height block, then zero dial indicator.
5. With dial indicator at zero, move gauge so that indicator plunger contacts arbor.
6. Move gauge assembly back and forth, recording indicator reading at highest point of contact. Repeat steps 4 and 5 several times to ensure accurate reading.
7. Indicator reading obtained in step 6 is proper shim thickness for "nominal" pinion.
8. Inspect face of drive pinion for modification code, described in preliminary shim selection and select pinion depth adjusting shims as follows:
a. If pinion depth code is a plus (+) number, subtract that number of thousandths from dimension obtained in step 6 and select shim pack equal to remainder.
b. If pinion depth code is a minus (-) number, add that number of thousandths to dimension obtained in step 6 and select shim pack equal to sum. If baffle or oil slinger is used, thickness of these components must be included in shim pack.