Chevrolet 1977 10 Series, Repair Manual, Page: 132 / 468

4B-60 OVERHAUL MANUAL
GEAR TOOTH CONTACT PATTERN CHECK
P rio r to final assem bly o f the d ifferential, a G e a r T ooth
C o n tact P attern Check is necessary to v e rify the correct
re latio n sh ip betw een rin g g e a r an d drive p in io n . G e a r
sets w hich are not positioned p ro p erly m ay be noisy, or
have sh o rt life, or both. W ith a p a tte rn check, the m ost
desireab le contact betw een rin g g e a r and d riv e p in io n
fo r low noise level and long life can be assured.
Gear Tooth Nomenclature
T he side o f the ring gear tooth w hich curves outw ard, or
is convex, is refe rred to as the " d riv e " side. T he concave
side is the "c o a st" side. T he en d o f the tooth n e a re st
cen ter o f rin g g ear is re fe rred to as the " to e " end. T he
end o f the tooth farth est aw ay fro m cen ter is the " h e e l"
end. Toe end o f tooth is sm aller th a n heel end. See
F igure 12F.
Test
1. W ipe oil out o f c a rrie r an d carefully clean each
tooth o f rin g gear.
Fig. 12F—Gear Tooth N om enclature
in setting the p in io n d ep th a n d the rin g g ear-to -p in io n
backlash.
Fig. 13F—Gear Teeth Contact Pattern Check