This vehicle provides fastener dimensions using the metric system. Most metric fasteners are approximate in diameter to equivalent English fasteners. Make replacements using fasteners of the same nominal diameter, thread pitch, and strength.
A number marking identifies the OE metric fasteners except cross-recess head screws. The number also indicates the strength of the fastener material. A Posidrive® or Type 1A cross-recess identifies a metric cross-recess screw. For best results, use a Type 1A cross-recess screwdriver, or equivalent, in Posidrive® recess head screws.
GM Engineering Standards and North American Industries have adopted a portion of the ISO-defined standard metric fastener sizes. The purpose was to reduce the number of fastener sizes used while retaining the best thread qualities in each thread size. For example, the metric M6.0 X 1 screw, with nearly the same diameter and 25.4 threads per inch replaced the English 1/4-20 and 1/4-28 screws. The thread pitch is midway between the English coarse and fine thread pitches.
Fastener Strength Identification

The most commonly used metric fastener strength property classes are 9.8 and 10.9. The class identification is embossed on the head of each bolt. The English, inch strength classes range from grade 2 to grade 8. Radial lines are embossed on the head of each bolt in order to identify the strength class. The number of lines on the head of the bolt is 2 lines less than the actual grade. For example, a grade 8 bolt will have 6 radial lines on the bolt head. Some metric nuts are marked with a single digit strength identification number on the nut face.
The correct fasteners are available through GM SPO. Many metric fasteners available in the aftermarket parts channels are designed to metric standards of countries other than the United States, and may exhibit the following:
The metric fasteners on GM products are designed to new, international standards. The following are the common sizes and pitches, except for special applications:
Fasteners
Prevailing Torque FastenersInstallation Procedure
Create 6 x 20 mm (4/16 x 12/16 in) slots for MIG-brazing along the edges
of the rear inner wheelhouse as noted from the original
panel.
Note: If the location of the original plug weld holes can
not be determined, space the slots every 40 mm (1½ in).
Clean and prepare the ...
Voice Recognition
Voice recognition allows for hands-free operation of the infotainment system
features.
Voice recognition can be used when the radio is on or when Retained Accessory
Power (RAP) is active.
See “Retained Accessory Power (RAP)” in the owner manual. The system maintains
a minimum volume level.
...
Installation Procedure
Cut the roof front header panel in corresponding locations to fit the
remaining original panel. The sectioning joint should be trimmed
to allow a gap of one-and-one-half-times the metal thickness at the
sectioning joint.
Create a 50 mm (2 in) backing plate from the unused portion of ...