Isuzu 1999 RODEO Workshop Manual page 1146

Selection of Adjusting Shim
Shim to be selected = (Thickness of removed shim) +
(Valve clearance measurement – Standard valu)
Based on the above formula, the best suited shim should
be selected from 41 sorts of shim (differently thick at
0.02mm (0.0008 in) intervals from 2.40mm (0.0945 in)
through 3.2mm (0.1260 in) thick). Install the shim and
check valve clearance.
Replacement of Shim
Let the cam push down the edge of tappet by using
J–42689 valve clearance adjusting tool and push out the
shim with a flat blade screw driver as shown in illustrations
below.
ENGINE MECHANICAL (6VD1 3.2L)
014RW082
014RW083
6A–61
014RW084