Advertisement
3-8
UNDERBODY
Fig. 3-8—Horizontal and Vertical Dimensions (Body Assembly)
3.
A visual damage inspection should be made to
eliminate needless measuring. Obviously dam-
aged or misaligned areas can often be located
by sight.
Tramming Sequence
The tramming sequence will vary depending upon
the nature and location of the misaligned area.
Prior to performing any tramming operation, the
accuracy of reference points to be used must be
determined. A measurement that originates from a
reference point which is included in a damaged
area will produce untrue results and confuse the
evaluation of the underbody condition. Unlike the
conventional type of frame design, the unitized type
of body construction seldom develops the condition
of "diamond'' in the floor pan area as a result of
front or rear end collisions. Therefore, underbody
alignment checking can usually originate from the
body floor pan area. If inspection indicates that
these locations have been disturbed and are not
suitable for measuring, one of the undamaged
suspension locations should be used as a beginning
reference point. If a rare situation should exist
where all of these locations are not suitable as
reference points, repair operations should begin
with the body floor pan area. All other underbody
components should be aligned progressively from
this area.
Underbody Alignment Reference Point
Dimensions (Figures 3-7, 3-8, and 3-9)
Dimensions to gage holes and other unthreaded
holes are measured to dead center of the holes and
flush to the adjacent surface metal. Dimensions
to bolt or bolt hole locations are measured to the
dead center of the thread diameter of the bolt or
bolt hole.
Figure 3-7 specifies dimension reference loca-
tions required for alignment of front end skirt
assembly and for alignment of front end skirt
assembly to body assembly. Figure 3-8 specifies
Advertisement
