Chevrolet 2008 T Series Owner's Manual page 260

(9) = Inspect rear axle air shift motor for fluid leaks.
Remove plug to check fluid level. Inspect air lines and
hoses for proper hook-up, binding, leaks, etc. Inspect at
1,000 miles (1 600 km) and 22,500 miles (36 000 km)
and then every 22,500 miles (36 000 km) thereafter.
(10) = Chassis Lubrication Service: Lubricate all grease
fittings in front suspension, front axle, and steering
linkage. Do not lubricate kingpin bushings with air
pressure equipment; instead, use a hand grease gun
to ensure complete purge and eliminate sealer cap
distortion. Front axle tie rod ends, both upper and lower
kingpin fittings, and both steering linkage relay rod ends
should be greased with the vehicle loaded on the ground
and wheels turned straight ahead, not with the vehicle on
a hoist. Apply kingpin bushing lubricant to both upper and
lower kingpin grease fittings until new lubricant purges
from between the upper shim pack and thrust bearing.
Lubricate transmission and shift linkage, tilt cab hinges
and latches, parking brake lever pivot, clevis pins and
linkage, disc brake caliper rails, bearing pads, propshaft
universal joints, brake camshaft bracket, slack adjusters,
and pedal shaft. Lubricate suspension, axle, and steering
linkage more often when operating under dusty or muddy
conditions and in excessive off-road use. Frequently
power-washed vehicles will require more frequent
lubrication.
6-18
(11) = Check steering system:
•
Look for damaged, loose, or missing parts. Inspect
the steering linkage relay rod and tie rod ends for
looseness or lack of lubricant. Also look for parts
showing signs of wear or lack of lubrication. Replace
parts as needed. Also check steering gear mounting
bolts, pitman arm nut, gear housing upper cover and
side cover attaching bolts, steering column mounting
bolts, and cardan joint clamp bolts; tighten if
necessary. See the service manual.
•
Inspect power steering hoses, tubes, and fittings for
leaks. Hoses and lines must not be twisted, kinked,
or tightly bent. Make sure clips, clamps, supporting
tubes, and hoses are in place and properly secured.
•
Check steering gear for leakage around pitman shaft
and housing. If leakage is evident (lubricant oozing
out, not just oily film), leak should be corrected
immediately.
(12) = Check front and rear suspension. Look for
damaged, loose or missing parts or parts showing signs
of wear or lack of lubrication. Replace parts as needed.