GMC 1976 ZEO 6083 Maintenance Manual page 515

INSPECTION
NOTE :
Do not remove the teflon oil seal ring
from the front accumulator piston unless the oil
seal ring requires replacement. For service, the
oil seal ring will be aluminum .
l . Wash control valve body, valves, and other
parts in clean solvent.
CAUTION:
Do not allow valves to bump
together, as this might cause nicks and
burrs.
2. Inspect all valves and bushings carefully to
make sure that they are free from dirt and are not
damaged in any respect. If burrs are present, they
should be removed with a fine stone or fine grade of
crocus cloth and light oil . Be careful not to round off
shoulders of valves .
3. All valves and bushings should be tested in
their individual bores to make certain that free move-
ment can be obtained . All valves should fall freely of
their own weight with a slight tapping action on the
body . In checking be careful to prevent valve damage
in any way.
4 . The manual valve is the only valve that can be
serviced separately . If other valves are damaged
beyond repair, a new control valve assembly should
be installed .
5. Inspect body for cracks or scored bores.
6. Check all springs for distortion or collapsed
coils.
7. Inspect piston and oil ring for damage.
ASSEMBLY (FIGURE 99)
1 . Position control valve body and cored face up
and accumulator pocket on bottom .
2 . Install the 1-2 accumulator primary spring
into top bore.
3 . Install the 1-2 accumulator valve, stem end out
into the top bore .
4. Install the 1-2 bore plug, hole end out, into the
top bores.
5 . Install grooved retaining pin, grooved end en-
tering hole last from outer side of valve body, press-
ing pin flush with valve body .
6. Insert spacer inside of 3-2 valve spring and
install spring and spacer in bottom left bore .
TRANSMISSION 7- 6 7
7 . Install 3-2 valve in bottom left bore .
8 . Compressing 3-2 valve spring, install bore
plug, hole end out, and secure with grooved retaining
pin from cored side of valve body .
9 . Insert spacer inside of detent regulator valve
spring and install spring and spacer into upper left
center bore, making certain spring seats in bottom of
bore .
10 . Compress detent regulator valve spring and
hold with a small screwdriver placed between end of
spring and
wall
on cored side of valve body .
11 . Install detent regulator valve, stem end out,
and detent valve, small land first, into upper left
center bore.
12 . Insert bore plug, hole out, into upper left
center bore and, pressing inward on bore plug,
remove screwdriver and install remaining pin from
cored side of valve body .
13 . Install 1-2 shift valve, longer stem end first,
in lower left center bore, making certain valve seats
in bottom of bore.
14 . Install 1-2 regulator valve, large stem first,
spring and 1-2 detent valve, hole end first, into 1-2
modulator bushing, aligning spring in bore of 1-2
detent valve. Install assembly into lower left center
bore of control valve body, open end of bushing first.
15 . Compress bushing against spring and secure
with retaining pin from cored side of control valve
body .
16 . Install 3-2 intermediate spring in open end of
2-3 shift valve, and install valve and spring, valve
first, into lower left bore . Make certain valve seats in
bottom of bore .
17 . Install 2-3 modulator valve, hole end first,
into 2-3 modulator bushing and install both parts in
lower left bore .
18 . Install 2-3 shift valve spring into hole in 2-3
modulator valve, and compressing spring, secure
with retaining pin from cored side of control valve.
19 . Position front accumulator spring and piston
into valve body and install Control Valve Accumula-
tor Piston Installer, J-21885, on piston . Compress
spring and piston, aligning spring and piston with
bore, Figure 100.
CAUTION:
Make certain that piston pin is
correctly aligned with hole in piston and
that oil seal ring does not catch on lip of
bore when
installing
piston.