CHEVROLET 2010 Silverado - Manual (Page 493)

Also, if a vehicle has just been driven before checking
the fluid level, it may appear lower than normal because
fluid has traveled out along the axle tubes and has not
drained back to the sump area. Therefore, a reading
taken five minutes after the vehicle has been driven will
appear to have a lower fluid level than a vehicle that
has been stationary for an hour or two. Remember that
the rear axle assembly must be supported to get a true
reading.
How to Check Lubricant
2500HD with 6.0L and 6.2L
All Other Series and Engines
To get an accurate reading, the vehicle should be on a
level surface.
. For all 4.3L, 4.8L and 5.3L 1500 Series
applications, the proper level is 0.04 inches to
0.75 inches (1.0 mm to 19.0 mm) below the bottom
of the filler hole, located on the rear axle. Add only
enough fluid to reach the proper level.
. For all 6.0L and 6.2L 1500 Series applications,
the proper level is from 0.6 inches to 1.6 inches
(15 mm to 40 mm) below the bottom of the filler
plug hole, located on the rear axle. Add only
enough fluid to reach the proper level.
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