CAB AND CHASSIS
11
SECTION 18
ASTRA HD8Ec
Finding chassis twist
Figure 27
17357
Slight torsion may only be detected with the cab and mech-
anical units removed. To make the check, proceed as follows:
-
place the chassis on two stands;
-
fasten one side of the chassis to the stand with two
clamps;
-
set the other side of the chassis on the knee of an ”L” iron
(1, Figure 27) in central position under the rear cross
member;
-
place a ruler in cross position and a spirit level (2,
Figure 27) on the ruler and check the readings.
The same value should result at each check point, otherwise
the chassis is deformed.
PRECAUTIONS
Figure 28
17358
When welding, drilling, grinding or cutting near the pipes of
the braking system, especially near plastic parts or electrical
wiring, take adequate precautions to protect them, and if
necessary, remove them. All parts of the chassis that are re-
conditioned are to be protected from oxidation and cor-
rosion.
Protection and painting operations are to be carried out accu-
rately on all the parts involved, following any instructions,
methods, and preventive precautions indicated by the paint
manufacturers.
Figure 29
17359
The chassis reconditioning is obtained by wedge heating the
part concerned with a torch.
During this operation the metal must become cherry red
coinciding with a temperature ranging between 600 and
680
°
C.
The points already heated must not be re-heated.
Let the heated points cool slowly without using water, com-
pressed air or other cooling agents.
Figure 30
17360
Straighten chassis lateral bending by wedge heating the upper
and lower edge of the chassis length concerned.
The wedge point must in the desired bending direction.
If the base (a, Figure 30) of the two wedges is on the upper
edge plate of the side member, the plate must also be heated,
but last.
