Adjust tooth contact pattern – Spicer Tandem Drive Axle Dual Range & Double Planetary 34,000-45,000 lbs User 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

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

tighten adjuster until it contacts the bearing cup.

Continue tightening the same adjuster 2 or 3

notches. Recheck backlash.