Pontiac tempest 1968 Service Manual page 537

7F-36 1968 P O N T I A C SERVICE MANUAL
C O N V E R T E R
L O W
APPLY
M O D U L A T O R L I N E R E V E R S E
C L U T C H .
F E E D ^ E X H A U S T \ F O R W A R D ^ > C L U T C H
M O D U L A T O R \ f
LINE
M O D U L A T O R : ' j .
E X H A U S T f-Z:
:
G O V E R N O R
• -
, G O V E R N O R
. E X H A U S T
- D R I V E
- G O V E R N O R
D E T E N T
M O D U L A T O R B O O S T
F O R W A R D C L U T C H - " LIMIT FEED
R E V E R S E
-/ ^ " — - C L U T C H
H I M I T E D M O D U L A T O R
Fig. 7 F - 1 0 9 Case V a l v e Body Passages
60 Check for leak at inner hole of low servo piston
assembly.
ENGiNt tLARES ON UPSHIFTS
Refer to Drive Clutch Plates Burned.
LATE UPSHIFT
1. Check vacuum line connections.
2. Stuck detent valve.*
3. Open detent solenoid or loose solenoid attaching
bolts.*
4. Sticky shift valve.
5. Check governor assembly.
*Will cause transmission to make only wide-open
throttle upshift.
UPSHIFTS-DOWNSHIFTS ERRATIC
1. Check for scored governor bore.
NO WIDE OPEN THROTTLE DOWNSHIFT
1. Check detent control switch operation and con­
tinuity in wiring (switch is self-adjusting).
2. Check for stuck detent valve and shift valves.
3. Check orifice in detent valve.
4. Check solenoid on valve body.
FORWARD CLUTCH
EXHAUST
FORWARD CLUTCH
PRESSURE
DRIVE PRESSURE
MODULATOR
BOOST
GOVERNOR
EXHAUST LIMITED MODULATOR
LIMIT FEED
I LIMITED MODULATOR
EXHAUST
MODULATOR
BOOST
EXHAUST
DETENT PRESSURE
Fig. 7F-110 Valve Body Passages
ENGINE FLARES ON WIDE OPEN THROTTLE
DOWNSHIFT
1. Check low band adjustment.
2. Check for restriction in vacuum line or fitting
to transmission.
3. Check for correct valve body plate.
DELAYED ENGAGEMENT OF MANUAL LOW
1. Check freedom of 2-piece modulator valve.
DRIVE CLUTCH PLATES BURNED
(Usually low band and reverse clutch good)
1. Check for leakage in clutch circuit.
2. Check ball in forward clutch drum.
3. Check clutch lines in front pump cover and
stator shaft assembly.
4. Plug in pump cover assembly missing.
5. Check clutch piston seals.
6. Check clutch feed oil rings.
7
e
Check for proper number of clutch plates and
correct piston.
DRIVE CLUTCH PLATES, LOW BAND AND
REVERSE CLUTCH PLATES-ALL BURNED
1. Check for following causes of low maximum line
pressure:
a. Modulator can load check.
b. Check for proper modulator can.