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