Pinion Gear to Ring Gear Engagement
The final position of the pinion gear is verified by using the gear contact pattern method as described in the fol- lowing procedure.
GEAR TOOTH DEFINITIONS (Fig. 41):
Toe
Heel
Top Land
1.Paint the teeth of the ring gear, both drive and coast side, with a gear marking compound, such as DyKemR Steel Blue.
2.Install the input shaft/pinion gear assembly into axle case.
3.While applying a light load to the ring gear, rotate the pinion gear in the direction of forward travel until the ring gear has made one complete revolution.
Ideal tooth contact observed on the ring gear should cover more than 35% of each tooth surface. The contact area should be in the center of each tooth and extend 1/3 to 1/2 way across each tooth from the toe end (Fig. 42).
Adjustments to the gear contact position are made by moving the input shaft/pinion gear (bearing case shims) or by moving the differential gear case (differential bear- ing shims) (Fig. 43).
NOTE: Bearing case shims are available in 0.004 in. (0.10 mm) and 0.008 in. (0.20 mm) thickness.
NOTE: Differential bearing shims are available in 0.004 in. (0.10 mm), 0.008 in. (0.20 mm) and 0.016 in. (0.40 mm) thickness.
Study the different contact patterns (Figs. 44 and 45) and correct gear engagement as necessary.
NOTE: When making changes, note that two variables are involved (see Gear Pattern Movement Summary in this section of this manual).
Example: If the pinion gear to ring gear backlash is set correctly to specifications and the bearing case shim is changed to adjust tooth contact, it may be necessary to readjust backlash to the correct specification before checking the contact pattern.
PROFILE
TOP LAND
TOE
LENGTHWISE
BEARING
ARC
HEEL
ROOT
Figure 41
More than 35% total tooth contact
1/3 to 1/2 of entire width from small end of tooth
Figure 42
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Figure 43
1. | Input shaft/pinion gear | 4. Differential bearing |
2. | Bearing case shims | shims |
3. | Differential gear case |
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Groundsmaster | Page 6 | Axles, Planetaries and Brakes |
