Chevrolet 1977 10 Series, Руководство по ремонту, Страница: 124 / 468

4B-52
OVERHAUL MANUAL
Fig. 17E—Gear Tooth N om enclature
C ontact P attern Check is necessary to v erify the correct
re latio n sh ip betw een rin g g ear an d drive pin io n . G e a r
sets w hich are not positioned p ro p erly m ay be noisy, or
have short life, or both. W ith a p a tte rn check, the m ost
d esireable contact betw een rin g g ear a n d drive p in io n
for low noise level and long life can be assured.
Gear Tooth Nomenclature
The side o f the ring g ear tooth w hich curves outw ard, or
is convex, is re fe rred to as the " d riv e " side. T he concave
side is the "c o a st" side. The end o f the tooth n earest
cen ter o f ring g ear is re fe rred to as the " to e " end. The
end o f the tooth fa rth est away 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 17E.
Pattern Check
1. W ipe oil out o f c a rrie r a n d carefully clean each
tooth o f ring gear.
2. Use g ear m ark in g com pound (yellow lead chrom ate
o r equivalent) and apply this m ixture to ring g ear
teeth. W hen p ro p erly ap p lied , the a re a o f tooth
contact will be clearly visible a fte r load is applied.
3. T ighten b earin g cap bolts to specifications.
4. A pply load to gears by ex p a n d in g b rak e shoes or by
w rap p in g a heavy rag aro u n d the c o m p an io n flange
to resist ro tatio n .
N O TE: A test m ade w ith o u t lo ad in g the
gears will not give a satisfacto ry p a tte rn .
T u rn com p an io n flange w ith w rench so th at
ring g e ar rotates one full revolution then
reverse ro tatio n so th a t rin g g e a r ro tates one
revolution in opposite d irectio n . Excessive
tu rn in g o f rin g g e a r is n o t recom m ended.
5. O bserve p a tte rn on rin g g e a r teeth an d com pare
w ith figure 18E. M ake ad ju stm e n ts as outlined
below.
6. The im p o rta n t th in g to achieve in the p a tte rn check
and subsequent ad ju stm en ts is to locate the contact
p a tte rn centrally on the face o f the rin g gear teeth.
Pinion Depth Adjustment
1. The p in io n d ep th shim m ay be replaced as
necessary to place the drive p in io n at the correct
depth. See figure 18E.
2. D epth shim s are av ailab le fro m .006 in ch to .024
inch, in increm ents o f .001 inch.
Backlash Adjustment
1. R em ove locking re ta in e rs fro m side b e a rin g
adju stin g nuts.
2. M ove adju stin g nuts
an equal amount
in or out to
achieve p ro p e r backlash.
a. To increase backlash, loosen the left adjusting
nut and tig h ten the rig h t ad ju stin g n u t
an equal
amount
b. To decrease backlash, loosen the rig h t adjusting
n u t and tig h ten the left a d ju stin g n u t
an equal
amount.