GMC T-Series 2007 Owner's Manual page 310

(8) = This vehicle has the Engine Oil Life System.
This system will show you when to change the
engine oil and filter – usually between 3,000 miles
(5 000 km) and 15,000 miles (24 000 km) since
your last oil change. Under severe conditions,
the indicator may come on before 3,000 miles
(5 000 km). Never drive your vehicle more than
15,000 miles (24 000 km) or 12 months without
an oil and filter change.
Remember to reset the Engine Oil Life System
whenever the oil is changed. For more information,
see Engine Oil Life System on page 209.
(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.
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(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.