Spicer Tandem Drive Axle Dual Range & Double Planetary 34,000-45,000 lbs - Manual (Page 25)

Adjust Tooth Contact Pattern
If necessary, adjust the contact pattern by moving the ring gear and
drive pinion. Ring gear position controls the backlash. This adjustment
moves the contact pattern along the face width of the gear tooth. Pinion
position is determined by the size of the pinion bearing cage shim pack. It
controls contact on the tooth depth of the gear tooth.
These adjustments are interrelated. As a result, they must be con-
sidered together even though the pattern is altered by two distinct
operations. When making adjustments, first adjust the pinion, then the
backlash. continue this sequence until the pattern is satisfactory.
Adjust Pinion Position
If the gear pattern shows incorrect tooth depth contact, change drive
pinion position by altering the shim pack. Used gears should achieve
proper contact with the same shims removed from the axle at disassembly.
INCORRECT PATTERN
/
●
Pattern too close to tooth top ‘land and off center.
INCORRECT PATTERN
Ž Pattern’ too close or off tooth root.
If the pattern is too close to the top land of the
gear tooth, remove pinion shims.
If the pattern is too close to the root of the gear
tooth, add pinion shims.
NOTE:
Check ring gear backlash after each shim change and adjust if necessary to maintain the 0.006” to
0.016” specifications.
If the gear pattern shows incorrect face width contact, change backlash.
INCORRECT PATTERN
●
Pattern too close to edge of tooth toe.
INCORRECT PATTERN
• Pattern too far along tooth toward tooth heel.
With the pattern concentrated at the toe (too far
down the tooth),
add backlash
by loosening the
bearing adjuster on the teeth side of ring gear sev-
eral notches. Loosen the opposite adjuster one notch.
If the pattern is concentrated at the heel (too
far up the tooth),
remove backlash
by loosening the
bearing adjuster on the teeth side of ring gear sev-
eral notches. Tighten the opposite adjuster one notch
Return to adjuster on teeth side of ring gear and Return to adjuster on teeth side of ring gear and
tighten adjuster until it contacts the bearing cup. tighten adjuster until it contacts the bearing cup.
Continue tightening the same adjuster 2 or 3 Continue tightening the same adjuster 2 or 3
notches. Recheck backlash. notches. Recheck backlash.
25