GMC Sierra Classic 2007 Owner's Manual page 69

Crew Cab Models
1. If the child restraint manufacturer recommends
that the top tether be attached, attach and
tighten the top tether to the top tether anchor,
if your vehicle has one. Refer to the child
restraint instructions and the following steps:
1.1. To access the top tether anchors,
raise the seat cushion by pulling up
on the strap loop at the rear of the seat
cushion and fold the seat cushion
forward. Then fold the seatback forward.
See Rear Seat Operation (Extended
Cab) on page 19 or Rear Seat
Operation (Crew Cab) on page 20 for
additional information.
1.2. Place the child restraint in the
vehicle, near the seating position
that you are using.
1.3. Route the top tether according to your
child restraint instructions and the
following instructions:
If the position you are
using does not have a
head restraint and
you are using a single
tether, route the
tether over the
seatback.
If the position you are
using does not have a
head restraint and
you are using a dual
tether, route the
tether over the
seatback.
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