BMW 3 1992 User Manual

FUNDAMENTALS FOR THE DO-ITYOURSELF OWNER

010- 5
WARNING -
Avoid
getting tools or
clothing
near the
battery .
Bat-
tery electrolyte is a corrosive acid . Be careful with
brake fluid, as it can damage
the
cars
paint Finally,
keep rubber parts such as hoses and bolts free
from oil orgasoline, as they will cause the material
to soften and fail prematurely .
Non-reusable Fasteners
Many fasteners used on the cars covered by this manual
must be replaced with new oses once they are removed . These

Fig . 4 . General sequence for alternately tightening multiple fasten-
include but are not limited to : bolts, nuts (self-locking, nylock,

ers .
etc .), cotter pins, studs, brake fittings, rol¡ pins, clips and wash-
ers . Genuine BMW parts should be the only replacement
parts

NOTE-
used for this purpose .

" Metric bolt classes or grades are marked on
the bolt'
head
.
Some bolts
are designed to stretch during assembly and are
permanently altered rendering them unreliable once removed .
These
are known as torque-to-yield fasteners . Always replace
fasteners where instructed to do so . Failure to replace these
fasteners could cause vehicle damage and
personal injury .
See an authorized BMW dealer
for applications and ordering
information .
Tightening
Fasteners
When tightening the bolts or nuts that attach a component,
it
is always good practice to tighten the bolts gradually
and evenly
to avoid misalignment or over stressing
any one portion of the
component . For components
sealed with gaskets, this method
helps to ensure that the gasket
will seal properly and complete-
ly
.
Where
there are severa¡ fasteners, tighten them
in a se-
quence alternating between opposite sides of
the component .
Fig
. 4 shows such a sequence for tightening six bolts
attaching
a typical component . Repeat the sequence
until al¡ the bolts are
evenly tightened to the proper
specification .
"
Do
not confuse wrench size with bolt diameter size .
For a listing of the common wrenches used on vari-
ous bolt diameters, see Basic Tool Requirements .
Table a . General Bolt Tightening Torques in Nm
(max . permissible)
Bolt Class (according
to DIN 267)
Bolt
diameter
5 .6 5 .8 6 .8 8 .8 10 .9
12 .9
M5 2 .5 3 .5
4 .5 6 8 10
M6

4
.5

6

7 .5

10

14 ` 17
M8

11

15 -

18

24

34

40
M10 23 30 36 47 66 79
M12 39 52 62 82
115 140
M14 62 82
98 130 180 220
M16 94
26 150 200 280 340
M18 130 174 210 280 390
470
For some repairs a
specific tightening sequence is neces-
sary, or a
particular order of assembly is required . Such special

Gaskets
and Seals
conditions
are noted in the text, and the necessary sequence
is
described
or illustrated . Where no specific torque
is listed, Ta-

The smoothest metal mating surfaces
still have imperfec
blea
can be used as a general guide for
tightening fasteners .

tions that can allow leakage . To
prevent leakage at critica¡
joints, gaskets of soft,
form-fitting material are used to fill in the
WARNING -

imperfections .
Table a is a general reference
only . The values list-
ed in the table are not intended
to be used as a sub-

To
be
most effective, gaskets are designed to crush
and be-
stitute for torques
specifically called out in the text

come thinner as the mating parts are
bolted together . Once a
throughout
this manual .

gasket has been used,
it is no longer capable of making as
good a sea¡ as
when new, and is much more likely to leak
. For
this
reason, gaskets should not be reused . Always
plan to use
new gaskets for any reassembly . Some
gaskets-such as
head gaskets-are directional
. Make sure that these are in-
stalled correctly
. This same logic applies to any part
used for
sealing, including rubber O-rings and copper
sealing washers .
ADVICE FOR THE BEGINNER

BMW 3 1992 Specifications

General

Brand	BMW
Model	3 1992
Category	Automobile
Language	English