Transmission Oil Pressure Checks - Pontiac Grand Prix Service Manual

7G-50 1969
PONTIAC SERVICE MANUAL
Fig.
76-129 Oil
Pressure Checks-Road or Normal Operating Conditions
With vacuum line connected and pressure gage installed:
SUPER Range:
SELECTOR LEVER IN-
DRIVE
-
1st Gear ( 0 to WOT)
-
2nd Gear ( 0 to WOT)
-
3rd Gear (Coast @ 30 mph)
SUPER (Coast @ 30 mph)
LOW
(Coast @ 30 mph)
REVERSE ( 0 to WOT)
Position selector lever in SUPER range, accelerating
vehicle from 0 mph. A 1-2 shift should occur at all
thiottle openings, the shift point varying with the
throttle opening. No 2-3 shift should be obtained in
this range. As vehicle speed decrease to 0 mph, a 2-1
shift should occur.
LOW Range:
WOT-Wide Open Throttle
MINIMUM PSI
67
67
67
95
95
96
Position selector lever in LOW range. No upshift
should occur in this range, regardless of throttle
opening.
MAXIMUM PSI
175
175
-
-
-
251
Second Gear Engine Braking:
Position selector lever in DRIVE range and, with
vehicle speed at approximately 30 mph and foot off
accelerator, move selector lever to SUPER range.
Transmission should immediately downshift to second
gear. An increase in engine
rpm
and an engine
braking effect should be noted. Line pressure should
change from 55 psi to approximately 80 psi in second
gear.
First Gear Engine Braking:
With selector lever in SUPER range and, with vehicle
speed at approximately 30 m h at constant throttle,
move selector lever to LO
4
range. Transmission
should downshift to first Fear. An increase in engine
rpm
and an engine bralung effect should be noted.
Line pressure should remain constant (approximately
80 pail.
TRANSMISSION OIL PRESSURE CHECKS
OPERATING CONDITIONS
While road testing vehicle with the transmission oil
pressure gage attached and the vacuum modulator
tube connected
,
the transmission line pressures should
check approximately as shown in Fig. 7G- 129.
II. OIL PRESSURE CHECK VEHICLE COASTING AT
25 MPH
While vehicle is coasting at 25 rnph (foot off throttle),
transmission oil pressure gage attached and the
vacuum modulator tube connected
,
the transmission
line ressures should check approximately as shown in
Fig.
!
G-130.
.
Vehicle coasting @ 25 mph, vacuum line connected,
pressure gage installed and foot off throttle:
SELECTOR LEVER IN- PRESSURE (PSI)
NEUTRAL 67
*
5
DRIVE 67
*
5
SUPER 9 0 * 5
LOW 9 0 * 5
REVERSE 9 0 * 5
Fig.
76.130 0 1 1
Pressure Checks-
Vehicle Coasting