Suspension; Setting Ride Height - Peterbilt 579 Operator's Manual

SUSPENSION

SUSPENSION

Setting Ride Height

Vehicles equipped with rear air
suspensions have their ride height and
axle (pinion) angle(s) preset at the
factory. These are precision settings
and should not be altered. Incorrectly
adjusted ride height may result in
improper interaxle U-joint working
angles. This can result in pre-mature
driveline wear and driveline vibration.
4
If your vehicle is equipped with a
Peterbilt rear air suspension, and if it
becomes necessary to reset the ride
height, you may temporarily set it by
following the next procedure. Proper
ride height measurement and values
for a fully laden vehicle are shown in
the illustration and table below.
4-48
Ride Height Measurement (Location
for Tandem Axles Shown)
Fully Laden Vehicle
Proprietary Ride Height,
Rear inches (mm)
Air Tandem
Single Drive
Suspension
Air Leaf N/A 11.70 (297)
Air Trac 11.00 (279) 11.00 (279)
Low Air Leaf 6.50 (165)
Low Low Air
N/A
Leaf
FLEX Air N/A
Y53-6047–2C
Unladen Vehicle
Proprietary
Rear
Air
Suspension
Air Leaf
Air Trac
Low Air Leaf
(Before April
2004)
Low Air Leaf
(After April
2004)
Low Low Air
Leaf
FLEX Air
Follow this procedure to temporarily
Drive
set ride height.
8.50 (216)
6.50 (165)
Ensure that a vehicle is parked and the
wheels chocked before beginning this
8.50 (216)
procedure.
Ride Height,
inches (mm)
Tandem
Single Drive
Drive
N/A 12.0 (305)
11.38 (289) 11.38 (289)
8.75 (222) 8.75 (222)
6.75 (171) 8.75 (222)
N/A 6.75 (171)
N/A 8.75 (222)
WARNING!
(04/13)