Tico Pro-Spotter, Руководство по обслуживанию

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1-12 Service Manual
TICO Manufacturing
GENERAL INFORMATION PRO-SPOTTER
Tightening Sequences and
Procedures
Torque
It is important that fasteners get tightened using the
correct torque value. Too much torque can cause the
fastener to break or become weak. Not enough torque
will cause the fastener to be loose. Be sure to follow the
torque instructions in this TICO service manual or the
provided manufacture’s manual. If a specific torque value
is not listed, use the torque chart found in this section.
The size and grade or property class must be known to
determine how much force to use. More torque can be
used on fasteners with higher grade and property class
ratings.
Tightening Sequences
It is important to understand how a tightening sequence
works to prevent bending or deforming of components.
When fasteners are arranged in a pattern, they must be
tightened or loosened in a specific order. Oil pans and
cylinder heads are a couple examples that use fasteners
in a pattern.
Follow the instruction in this TICO service manual for the
correct tightening sequence. If the sequence is not
stated, start by installing all nuts and bolts only finger
tight. Then apply one full turn to each fastener, working in
a star pattern. Repeat the star pattern, only applying one
half turn for this sequence. Lastly, tighten each fastener
by applying one quarter turn until the proper torque is
reached. The reverse of this process is used to remove
fasteners.
Figure 1-11: Tightening Sequence
TORQUE CHART
This torque chart is to be used as a guide when specific
torque values are not listed in the instructions. The torque
values in the chart are approximate and are for reference
only when tightening fasteners. It is recommended that
nuts and bolts be of the same standard grade. If a nut
and bolt are of different grades, use the torque value of
the lower grade fastener.
The torque values in the Standard Fastener Torque
Values table, See Table 1-1 on page 1-13, are based on
a bolt pre-load stress of 75% of the proof strength. Grade
2 fasteners with a bolt size from 3/8” to 3/4” have a proof
strength of 55 000 psi. Bolt sizes from 7/8” to 1-3/8” have
a proof strength of 33 000 psi. Grade 5 fasteners with a
bolt size from 3/8” to 1” have a proof strength of 85 000
psi. Bolt sizes from 1-1/8” to 1-3/8” have a proof strength
of 74 000 psi. Grade 8 fasteners have a proof strength of
120 000 psi.
The torque values in the Metric Fastener Torque Values
table, See Table 1-2 on page 1-13, have a proof strength
equal to or greater than the tensile strength of the bolt. A
Class 4.6 fastener will have an approximate tensile
strength of 400 MPa (58 015 psi) and 80% yield strength.
Class 8.8 fasteners will have an approximate tensile
strength of 800 MPa (116 030 psi) and 80% yield
strength. Class 10.9 fasteners will have an approximate
tensile strength of 1 000 MPa (145 038 psi) and 90%
yield strength.
IMPORTANT
Applying too much or too little torque can cause
damage to components. Caution should always be
used when applying any torque value. Use these
torque values at your own risk.
12
1
5
9
3
7
11
2
6
10
4
8
TPS-017