No. Standard measurement point Hole-Size shape. mm (in)
1 Centre of front bumper position hole – RH _ – 9 mm (0.354 in)
1a Centre of front bumper position hole – LH _ – 9 mm (0.354 in)
2 Centre of front sidemember positioning hole – LH _ – 25 mm (0.984 in)
2a Centre of front sidemember positioning hole – RH _ – 25 mm (0.984 in)
3 Centre of suspension crossmember mounting hole – LH _ – 16 mm (0.629 in)
3a Centre of suspension crossmember mounting hole – RH _ – 16 mm (0.629 in)
4 Centre of front floor sidemember positioning hole – LH _ – 15 mm (0.59 in)
4a Centre of front floor sidemember positioning hole – RH _ – 15 mm (0.59 in)
5 Rear portion of rear seat crossmember positioning hole – LH – 25 _ 38 mm
(0.984 _ 1.496 in)
5a Rear portion of rear seat crossmember positioning hole – RH – 25 _ 38 mm
(0.984 _ 1.496 in)
6 Centre of rear floor sidemember drain hole – LH _ – 10 mm (0.393 in)
6a Centre of rear floor sidemember drain hole – RH _ – 10 mm (0.393 in)
7 Rear portion of rear floor sidemember extention positioning hole – LH – 18 _ 67 mm
(0.708 _ 2.637 in)
14.3.7 Vehicle body alignment: upper
Structure
Damage to the inner construction of a car body
might be quite severe although not obvious. In
some cases the damage to the outer panels of the
body can be repaired and the original damage
will appear to have been corrected although
it has not. Failure to check the correction of
the internal damage by alignment methods can
result in incorrectly fitting doors, bonnets and
boot lids.
The alignment methods are based on comparative
measurements in which one distance is compared,
by means of a trammel, tram-track gauge or measuring
equipment incorporated in an alignment
measuring system (such as in Figure 14.70) to
another which should be the same. Comparative
measurements are universally used and are
regarded as the easiest and quickest method of
measuring collision work. These measurements
are supplied by most manufacturers on data sheets
or in body alignment manuals. Body measurements
are made in the same way in both composite
and mono constructed vehicles. Checking body
measurements is done by a system of diagonal
comparisons, commonly called X checking. The
444Repair of Vehicle Bodies
Figure 14.66Manufacturer’s transverse alignment points
Figure 14.67Alignment and repair using a jig
bracket system (Globaljig, Tri-Sphere Ltd )
Figure 14.68Alignment and repair using a
measuring bridge system (Blackhawk Automotive Ltd )
location and extent of the damage is determined
by measuring the body. Further measuring during
the repair will indicate when alignment is restored.
In this system of measuring the body is divided
into two basic sections: the front section, which
is the area from the centre pillar forwards
(Figure 14.72); and the centre/rear section, which
is the area from the centre pillar backwards to
the rear boot compartment (Figure 14.73). In
addition to these sections, there are special
sets of measurements for the alignment of the
bonnet lid, the boot lid, and the front and rear
doors. Some alignment systems incorporate
upper body alignment measuring equipment (see
Figures 14.74–14.77).
Door alignment
The doors of a car body are said to be misaligned
when they do not fit the contour of the body or when
they do not fit in the door opening correctly. Doors
must provide a good seal against dust, water and air,
and in order to do this they must match the contour
of the body at all points. When closed, doors must
fit correctly into the opening provided for them,
because if the door is incorrectly positioned it will
Major accident damage 445
not close properly and the gap around the door will
not be uniform. In some cases where the door
appears to be misaligned the door itself is not the
cause of the fault, and so it is advisable to X check
the body at the forward and centre positions to determine
whether the reason of the failure to match
the body contour is due to distortion of the body or
distortion of the door itself. In some cases lack of
uniform clearance at the front of the door might be
due to mispositioning of the front wing.
Door alignment is checked by making a visual
close inspection of the door and its relation to
the surrounding body panels. First open and close
the door and observe any movement at the edge
of the door at the lock pillar; if there is any up
and down movement, the door is out of alignment
but is being corrected by the dovetail of the lock
as the door closes. Look for signs of rubbing
or scraping by the bottom edges of the door on
the sill panels or centre pillar. Scrub marks are
evidence of a condition known as door sag. In
cases where the door is severely damaged and
a good deal of straightening is necessary, it is
essential to check the door before any attempt
is made to reinstall and to align the door with
the body. Measurements should be taken on the
damaged door, working from points that can be
easily established on an undamaged door, and the
readings compared to determine whether the damaged
door requires further attention. Always be
sure to take measurements from the same points
on both doors.
Figure 14.69Alignment and repair using a laser
measuring system (Dataliner, Geotronics Ltd )
Figure 14.70Autorobot L using full measuring
system (Kroll (UK) Ltd )
Figure 14.71Alignment system using electronic
measuring for both underbody and upper body
structures (Car-O-Liner (UK) Ltd )
446Repair of Vehicle Bodies
Figure 14.72Front diagonal alignment check