GMC 4000 Series Service Manual page 73

Sec. 1
Page 66
BODY M OUNTINGS
STUD TYPE M O U N T IN G
1 Lock Nut
2 Nut
3 Clip Plate (not tapped)
4 Metal Channel
5 Longitudinal Sill
extend beyond width of frame flanges to permit
grooving blocks to maintain position of mounting
bolts. If desired, block can be attached to sill with
screw s as shown in figure 2.
Wood grain of block should be perpendicular
(up and down) to grain of sill.
5. Wood sills must be chamfered 1/2" at the
front end, tapering to meet the frame 12 to 18
inches from end of sill (fig. 1). Tapered front of
sill is required for all Van or torsionally rigid
bodies. Notch or spot drill sill to clear the rivet
heads.
6. To prevent mounting clip plate becoming
embedded in longitudinal sill, install a sheet metal
channel on top of sill at each mounting point (figs.
1, 2, and 3). Rabbet grooves along each side of
top edges of longitudinal sills to permit flush
mounting of sill channels.
G M C S E R V I C E M A N U A L
T A P P E D PLATE TYPE M O U N T IN G
6 Spacer Block
7 Frame Side Rail
8 Wood Filler Block
9 Mounting Stud
10 Clip Plate (Tapped)
Figure 2 — Recom mended Methods of M ounting Body
one near rear end of sill, and space others as
nearly equal as possible between front and rear
mountings. It may be necessary to vary distances
to clear chassis brackets, etc., but approximately
equal spacing should be maintained.
a diameter of at least 7/16" and preferably 1/2"
for each mounting. Use a clip plate, of same thick­
ness as diarneter of bolts, at upper ^nd lower end
of bolts. Use at least three, and preferably four
mountings on each side.
mountings; however, carriage bolts, U-bolts, and
threaded rods (studs) can also be successfully
employed. If design of body does not permit use
U-BOLT TYPE M O U N T IN G
11 Mounting Bolt
12 Lock Washer
13 U-Bolt Clip
14 U-Bolt
MOUNTING BOLTS
1. Install one mounting near front end of sill,
2. Use two bolts or studs of proper length with
3. Hex head bolts are preferred for body
TP-9732- 1