Page 207 of 378

Climate Control System
Have the air conditioning system checked each spring. The refrigerant
charge, cleanliness of the condenser-evaporator cores and belt condition
are essential to system performance.
When the air conditioning system is being used daily, remove the fresh
air filter (if equipped) once each season and check for dirt, lint, etc.
Replace the filter if necessary. Vehicles operating in unusually dusty
conditions may require more frequent filter inspection and replacement.
Front Axle
Maintaining the front axle alignment to specifications is very important
and should only be performed by a qualified technician. Regular
inspections should include:
•toe-in inspection and adjustment (if necessary), particularly with
radial tires.
•checking for proper tightness of axle mounting U-bolt nuts, attaching
or mounting bolts and nuts.
•checking the axle for damage, binding, worn parts and adequate
lubrication..
•checking the kingpins for excessive wear. This should also be done
during other scheduled maintenance (tire rotation or service, wheel
bearing service, alignment, etc.). See the workshop manual for proper
procedures.
Toe-in
It is essential that correct toe-in and tire pressure be maintained for
optimum tire wear.
Inspecting steer axle tires in the first 3000–10000 service miles
(5000–16000 service kilometers) generally shows if tires are wearing
normally.
Rapid outside shoulder wear on both tires indicates too much toe-in.
Rapid inside shoulder wear on both tires indicates too much toe-out.
In P&D-type service, left-to-right steer tire tread life differentials up to
40% can be observed depending on routes and other variables.
Follow the tire manufacturer’s recommended cold inflation pressure for
the tire size, load range (ply rating) and steer axle loading typical for
their operation (each steer axle tire equals
1 2steer axle loading).
206Maintenance
2013 F-650/750(f67)
Owners Guide gf, 2nd Printing, March 2013
USA(fus)
Page 208 of 378
Special applications may warrant a setting based on experience with the
type of tire operating loads and conditions. Radial tires are more
sensitive to toe-in setting than bias ply tires. While not insensitive to
vehicle alignment, fine tuning school bus alignment to line-haul truck
standards does not drastically improve tire tread life.
Rear Axle
Regular inspections should include:
•checking for proper tightness of axle mounting U-bolt nuts, attaching
or mounting bolts and nuts. SeeSpring U-bolt checkslater in this
chapter.
•checking the axle for damage, binding, worn parts and adequate
lubrication.
NoSpin Detroit Locker Positive Locking Differential
Vehicles equipped with this type differential have the operator’s manual
supplied with the vehicle. See that manual for maintenance inspections.
Maintenance207
2013 F-650/750(f67)
Owners Guide gf, 2nd Printing, March 2013
USA(fus)
Page 279 of 378

Eaton-Spicer
Axle CodeWeight Capacity - lb
(kg)DescriptionCapacity -
Pints
(Liters)
*
21060S 21000 (9525) Single reduction 28.0 (13.2)
21060D 21000 (9525) Single reduction,
driver-controlled
locking differential28.0 (13.2)
M210T 21000 (9525) Two-speed 16.0 (33.0)
23090S 23000 (10432) Single reduction 39.0 (18.5)
23090D 23000 (10432) Single reduction,
driver-controlled
locking differential39.0 (18.5)
23082T 23000 (10432) Two-speed 37.0 (17.5)
*Quantities listed are approximate. Fill axle until the lubricant level is at
the bottom of the filler hole, with the vehicle on level ground.
If hubs are removed, add an additional 1.6 pints (0.75 liters) of axle
lubricant. Add lubricant through the axle vent.
Meritor
Axle Model Capacity - Pints (Liters)*
RS-17–140 28.6 (13.5)
RS-17–144 32.0 (15.0)
RS-17–145 33.6 (15.9)
RS-17–220 30.7 (14.5)
RS-17–224 29.0 (13.0)
RS-19–144 32.0 (15.0)
RS-19–145 33.2 (15.7)
RS-19–220 30.0 (14.0)
RS-19–223 29.0 (13.0)
RS-21–145 32.3 (15.3)
RS-21–160 39.0 (18.0)
RS-21–230 38.9 (18.4)
RS-23–160 39.5 (18.7)
RS-23–161 37.2 (17.6)
278Capacities and Specifications
2013 F-650/750(f67)
Owners Guide gf, 2nd Printing, March 2013
USA(fus)