470 External Equipment; Roof Air Deflector, Setting Instructions - Volvo FM Handbook

470 External equipment

Roof air deflector, setting instructions

The following requirements must be met to obtain
correct adjustment and effect from the roof spoiler:
• The truck must be parked on a flat surface.
• The tyres must have the correct tyre pressure.
• Trucks with air suspension must have the correct
pressure in the compressed air system.
• The cab hinges must be intact.
• Neither driver or passenger may be inside the cab
during adjustment of settings.
Clarifications
H = difference between H1 and H2.
H1 = height of body. Measurement should be made
from the top of the chassis, or from the ground to the
top of the body.
H2 = cab height. Measurement should be made from
the top of the chassis (compare H1) and to the upper
edge
of the rain gutter on the rear of the cab.
G = distance between the cab rear side (at rain gutter)
and body front side.
A = adjustment stay.
A1 = top hole of stay.
Calculation example
An FH with long low cab has:
H1 = 3700, H2 = 2750
H = H1 – H2 = 950
G = 700
Enter the values in the diagram for an FH with long
low cab and read off. In this case field A4. Therefore
use hole A4. If the read-off point approaches the upper
border line of the field, choose the next field.
Note!
If any of the values are changed, a
new setting of the spoiler must be
made.