|
|
4-Speed-Automatic
Transmission A 28
|
Type
|
Equipment
|
installed
in
|
Model
Year
|
|
A
28/04
|
4
speed
|
928
S USA/Japan
|
1985
|
|
A
28/05
|
4
speed
|
928
S Europe/R.o.W.
rear
axle transm. ratio 14:33
|
1985
|
|
A
28/06
|
4
speed
|
928
S Europe/R.o.W.
rear
axle transm. ratio 13:33
|
1985
|
|
A
28/07
|
4
speed
|
928
S USA/Japan
|
1986
|
|
A
28/08
|
4
speed
|
928
S Europe/R.o.W.
rear
axle transm. ratio 14:33
|
1986
|
|
A
28/09
|
4
speed
|
928
S Europe/R.o.W.
rear
axle transm. ratio 13:33
|
1986
|
|
A
28/11
|
4
speed
|
928
S Australia,
M-298/299
|
1986
|
|
A
28/12
|
4
speed
|
928
S4 USA
|
1987/88
|
|
A
28/14
|
4
speed
|
928
S4 Europe/R.o.W.
|
1987/88
|
|
A
28/16
|
4
speed
|
928
S4 worldwide
|
1989
|
|
General
Data
|
A 28.04/07/12
|
A
28.05/06/09/11/14/16
|
|
Design
|
Fully
automatic 4-speed sun-and-planet transmission
|
|
Ratios
1st
gear
2nd
gear
3rd
gear
4th
gear
Reverse
gear
|
A 28.04/05/06/06/08/09/11/12/14
3.6760
2.4120
1.4360
1.0000
5.1390
|
A 28.16
3.87
2.25
1.44
1.00
5.59
|
|
Final
drive
|
Drive
pinion without hypoid displacement
|
|
Final
drive ratio
|
15:33
i = 2.200
|
14:33
i = 2.357 (A 28.05/08)
13:33
i = 2.538 (A 28.06/09/
11/14/16)
|
|
Stall
speed
|
A
28.04/07 =
1650
2050
1/min
|
A
28.05/06/08/09/11
=
2200
2600
1/min
|
|
A
28.12
=
1750
2150
1/min
|
A
28.14/16
=
1750
2150
1/min
|
|
Capacity,
rear axle final drive
|
approx.
2.7 l (87 models onward, approx. 3.0 l hypoid transmission
oil.) API
classification GL5 (MIL-L 2105 B)
SAE
90
|
|
Capacity,
autom. unit with converter
|
Total
capacity = approx. 8.0 l (87 models onward, approx. 9.3 l).
Capacity for fluid change with converter = approx. 6.0
l (87 models onward, approx. 7.3l)
ATF
Dexron II D
|
Pressure Values in Bar, 87
Models Onward
|
Test
pressure
|
Transmission
Type A 28.12/14/16
|
Measuring
Instructions
|
|
Modulating
pressure*
|
4.2
+ 0.05
|
|
ATF
temp. approx. 80°C.
Selector lever in pos. D, driving speed approx.
140 km/h, vacuum
line disconnected at modulating pressure cell.
|
|
Operating
pressure
|
16.0
+ 1
|
|
ATF
temp. approx. 80°C. Selector
lever on D, engine running at 1400 rpm, parking brake engaged
and foot brake actuated.
Max.
test duration 5 sec. vacuum hose disconnected at modulator
unit.
|
|
Governor
pressure
|
A
28.14/16
approx.
0.2
approx.
1.1
approx.
2.0
approx.
2.7
|
A
28.12
0.17
0.96
1.74
2.35
|
at
20 km/h
at
50 km/h
at
100 km/h
at
150 km/h
|
Selector
lever in pos. D, vehicle rolls in partial load range,
vacuum line disconnected at modulating pressure cell.
|
*
N o t e
If
local constraints preclude testing the car at approx. 140 km/h
(88mph), measurements may be carried out at approx. 50 km/h (31 mph).
As
both versions use different final drive ratios, governor pressures
differ for USA/R.o.W. versions. The
USA governor rotates slower at given driving speed.
Standardized
transmission used worldwide from 1989 model year.
Gear
Shift Points in km/h
|
|
Transmission
Type
A
28.04/07/12
|
Transmission
Type
A
28.16
|
|
Accelerator
pedal position
|
km/h
|
km/h
|
km/h
|
km/h
|
|
Selector
lever position
|
▲
|
▼
|
▲
|
▼
|
|
Full
throttle D 1-2-1
Full
throttle D 2-3-2
Full
throttle D 3-4-3
Full
throttle 2 1-2
|
58
64
109
125
190
211
58
64
|
28
24
54
47
131
115
-
|
41
50
102
117
169
188
53
58
|
30
23
49
43
144
128
-
|
|
Kick-down
D 1-2-1
Kick-down
D 2-3-2
Kick-down
D 3-4-3
Kick-down
2 1-2
|
62
68
126
143
207
216
69
75
|
45
39
122
106
203
183
-
|
59
61
123
125
192
195
59
61
|
48
43
120
105
186
167
-
|
Note:
All speed specifications are approximate values.
Key
to symbols:
▲
Shift
up
▼
Shift down
|
