Ford F-650 2011 Supplement Manual page 222

Maintenance and Specifications
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.
SPRING U-BOLT CHECKS
Check U-bolt nuts and re-torque every 36,000 miles (58,000 km) after
initial 1,000 miles (1,600 km) re-torque. The U-bolt and nut threads and
seats should be cleaned and lubricated to ensure peak condition when
re-torqued.
U-bolt nut torque
Suspension
Front axle – 8500 lb (3856 kg)
Front axles – 10000 lb (4536 kg) and higher
Rear axle with multi-leaf
Rear axle with IROS air suspension
Rear axle with Hendrickson air suspension
See air suspension U-bolt re-torquing and installation information below.
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.
222
2011 F-650/750 (f67)
Supplement, 2nd Printing
USA (fus)
ft-lb N•m
180-200 244-271
260-300 353-407
260-300 353-407
370-400 502-542
400–450 542–610