GMC T Series 1994 Repair Manual page 534

A. Piston Crown Indent
B. C onnecting Rod
Bearing Tangs
Figure 40— Aligning the Piston and Connecting
Rod
116. PISTON PIN RETAINER
A. RING MUST EXTEND
BEYOND NOTCH
B. INSERT ONE END OF
RING IN RING GROOVE
C. RING SPLIT MUST BE
TOWARD
BOTTOM OF
PISTON
B9401
Figure 43— Retaining Ring Location
13 Inspect
• Retaining rings for proper assembly. Visually
inspect retaining ring to ensure it is seated in
the ring groove.
INSTALLING THE PISTON RINGS
• All compression rings are marked on the upper
side of the ring. When installing the compression
rings, make sure the MARKED SIDE IS TOWARD
THE TOP OF THE PISTON.
• The top compression ring is a keystone type.
• The oil ring is a two-piece type, consisting of an
expander and a scraper ring.
Measure (Figure 45)
Ring end gap as follows:
1. Select rings that will be used in the bore being
checked.
V3945
2. Slip the compression ring into the cylinder bore,
then press it down about 25 mm (1-inch) above
ring travel. Make sure the ring is square with
the cylinder wall.