Porsche 928 1982 Operating and installation instructions

LIST OF CONTENTS
Q
Engine
Crankshaft Bearings. .
Pulleys .
Alternator .
Check Valve . .
Tensioning Roller Carrier
Oil Pump.
Oil Pressure Valve
Power Transmission - Tranraxla System
Vibration Damper
Differential : : : : : :
Reverse Gear Lock-out ..
a
Running Gear
Rear Axle Shafts
Brakes .
Electrical System
Start Relay
Fuel Consumption Indicator
Miscellaneous
Equipment
e Air Conditioner
Survey of Number Ranges
Chassis Numbers
Engine Numbers .
Transmission Numbers
.
Specifications, Adjusting Values, Equipment Survey
Wiring diagrams
Page
2
4
5
6
7
a
10
12
14
16
19
20
26
28
30
31
32
33
34
.35
42

Porsche 928 - 1982 Models
For 1982, the 928 will have only minor modifications.
Survey of the most important changes:
Engine
0
One piece front main bearing
l
Check valve in cylinder head
0 Modified pressure relief valve
. Modified oil return flow (from shaft seal of oil pump)
. Improved mounting of toothed belt tensioning roller
. Alternator and pulleys
Transmission/Shift/Central Tube
0
Stronger differential shafts
. Reverse gear deflector
0 Vibration damper in central tube
Running Gear
.
Friction welded rear axle shafts
. Floating (fist) caliper brakes for US cars
Equipment
l
Fuel consumption indicator
0 Battery 88 Ah - Standard
l
EC0 Av switch position for climate control system
l
Luggage compartment light
l
Electric seats; automatic forward motion of seat when operating backrest omitted
1

ENGINE - Crankshaft
Crankshaft Bearings
The former split main bearing no. I (pulley end) is replaced by a one piece bearing. The bearing
has a lubrication groove on the inside as well as 4 slots. A heavy dowel pin, located in the crank-
case upper section, prevents turning.
2

ENGINE - Crankshaft
Tightening torque for crankcase studs (third step)
New 1 Old
Studs M 10 50+5Nmor 39.3 + 4.9 Nm or
36 4 ft. Ibs.+ 28.4 + 3.5 ft. Ibs.
Studs M 12 75+5Nmor 58.9 + 4.9 Nm or
54 + 4 ft. Ibs. 42.6 + 3.5 ft. Ibs.
All engines, which have been assembled with the higher tightening torque values, are identified
with an “X” near the case number (matching number for upper and lower case sections).
The tightening torque values 50 + 5 Nm (36 + 4 ft. Ibs.) and 75 + 5 Nm (54 + 4 ft. Ibs.) are
applicable to crankcases, which are marked with “X” and/or those with a one piece front main
bearing.
3

- r
ENGINE - Crankshaft
Pulleys
l
Beginning with 1982 models the alternator will be driven by a “polyrib” belt. Consequently
changes are made on the crankshaft and alternator pulleys. At the same time the alternator ratio was
changed from 1 : 2.15 to 1 : 2.3.
Note the following combinations.
-
UP to and
including 1981
Pulley
Crankshaft Alternator Alternator Drive Belt
I
928.102.116.05 928.603.131 .oo 928.603.113.03 999.192.135.50
92a.io2.i30.02 928.603.131 .oo 928.603.113.03 999.192.135.50
From 1982 92a.io2i39.02 928.603.145.02 928.603.114.00 999.192.214.50
92a.io2.i39.03 928.603.145.02 928.603.114.00 999.192.214.50
0
4

ENGINE - Electrical
Alternator
The 928 has a new alternator, rated at - 14 V - 90 A.
The cover and wire harness have also been changed.
5

ENGINE - Oil Supply, Tappets
Check Valve
A spring-loaded ball check valve (arrow) is installed in the oil supply bore to the cylinder heads.
The valve prevents return flow of the oil
(on a stopped engine) from the supply bore
for the hydraulic tappets.
This feature prevents the development of
tappet noise when engine is stopped for a
long time.
The valve cannot be installed in older cylinder
heads.

ENGINE - Timina
0
Tensioning Roller Carrier
The mounting of the tensioning roller carrier on the water pump housing is stronger.
The diameter of the bearing pin and bushing have been increased from 10 to 12 mm (0.394 to
0.472”); at the same time the width of the bearing eye was increased from 23 to 25 mm
(0.905 to 0.984”).
It is possible to retrofit older engines with the modified tensioning roller carrier.
0
Old
New
0
7

ENGINE - Lubrication
Oil Pump
Up to now the oil return bore from the shaft
seal led into the intake end of the pump.
Because of this led, it had been possible for
the pump to take in air through the shaft
seal.
-. -
TO prevent this, the return flow bore in the pump body has been modified in such a manner
that oil can flow directly
into the oil sump.
The crankcase lower section
has a return bore in the
area of the suction bore for
the oil oumo.