Tightening Fasteners - BMW 5251 Service Manual

General
Tightening fasteners
When tightening the bolts ornuts on acomponent, 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 meth-
od helps to ensure that the gasket will seal properly.
WARNING
-
Table a: General bolt tightening torques in N m (max.
permissible) is a general reference only The values listedin
the table are not intended to be usedas a substitute for tor-
ques specifically called out in the text or in manufacturer's in-
formation.
4
Where there are several fasteners, tighten them in a se-
NOTE-
*
Metric bolt classes or grades are rnarlced on the bolt head.
*
Do not confuse wrench size with bolt diameter. Fora listing
of the common wrenches used on various bolt diameters,
see Basic tool requirements.
2
BOO~FNG
quence alternating between opposite sides of the compo-
nent. Repeat the sequence until all the bolts are evenly
tightened to the proper specification.
For some repairs a specific tightening sequence is neces-
sary, or particular order of assembly is required. Such special
conditions are noted in the text, and the necessary sequence
is described or illustrated. Where no specific torque is listed,
Table a: General bolt tightening torques i n Nm (max. per-
missible) can be used as a general guide for tightening fas-
teners.