Pontiac Fiero 1988 Service Manual page 776

HYDRAULIC DIAGNOSIS 125C-3S
REVERSE
DIRECT CLUTCH - APPLIED
10
AND REVERSE CLUTCH - APPLIED
When the selector lever is moved to the Reverse (R) position, the manual valve is repositioned to allow
line pressure to enter three (3) passages, as follows:
1.
Reverse
2. RNDI (Reverse, Neutral, Drive and Intermediate)
3. RND (Reverse, Neutral, and Drive)
FIRST — Reverse oil from the manual valve seats direct clutch and reverse checkball (5) in the direct
clutch passage and flows to both the inner and outer areas of the clutch piston, applying the direct
clutch. Reverse oil also seats the lo and reverse checkball (4) in the lo 1st passage and applies the
lo and reverse clutch. Reverse oil flows to the reverse boost valve and will boost reverse line pressure
to about 8 2 7 kPa (120 psi).
SECOND — RNDI oil from the manual valve flows to the throttle valve and is regulated to T.V. pressure.
T.V. oil flows through the shift T.V. valve and is limited by it to approximately 6 2 0 kPa (90 psi).
Oil from the shift T.V. valve is directed to the T.V. boost valve. Shift T.V. oil acting on the T.V. boost
valve will boost reverse line pressure to approximately 1447 kPa (210
psi).
THIRD — RND oil from the manual valve is directed to the 2-3
shift valve, but this has no function
in Reverse.
SUMMARY
The direct clutch is applied. The lo and reverse clutch is applied. The transmission is in Reverse (R).
JH0028-125C
Figure 32 Reverse