WARNING:
Do not use a jack when working under a vehicle. It
may give way, causing the vehicle to fall and result in property
damage, personal injury or death. Always use floor stands to support
the vehicle.
FRAME AND TOW HOOKS
Your vehicles chassis is manufactured with frame rails of either HSLA
steel or heat-treated steel. Each must be handled in a specific manner to
ensure maximum service life. Before attempting frame repair or
modification, consult the service manual or your dealer.
It is important, particularly on vehicles where the tow hooks are used
frequently, to inspect the front and rear tow hooks for damage or a loose
mounting.
U-BOLT NUT TORQUE
U-bolt diameter (nominal) (all
spring suspensions)
U-bolt diameter (nominal)
Ft. lb.
N
•
m
IROS Air w/15,500 lb. axles and
less
260–300
353–407
IROS Air w/greater than 15,500 lb.
axles
370–400
502–542
Hendrickson 23,000 lb. axle
370–400
502–542
Air suspension U-bolt checks and re-torquing procedures
1. Inspect the threads of the U-bolt and nut for rust and debris. Clean
the threads if contaminated.
2. Using a torque wrench, determine if any nuts can be turned with a
force below the specified torque.
3. Using the lowest discovered torqued nut as a starting point, retighten
the nuts using the sequence listed under
Air suspension U-bolt and
U-bolt nut installation
.
Air suspension U-bolt and U-bolt nut installation
1. Inspect the threads of the U-bolt and nut for rust and debris. Clean
the threads if contaminated.
2. Install the U-bolts and nuts and torque the nuts to 15 ft. lb. (20 N
•
m),
using a diagonal pattern.
2009 F-650/750
(f67)
Supplement
USA
(fus)
Maintenance and Specifications
205
