Table of Contents
Advertisement
3 0 5 - 3 5 0 ENGINE
6A6-23
PRESS
PISTON PIN
INSTALLER
J-24086-9
Fig. 6A6-52 Assembling Connecting Rod and Piston
Assemblies
3. Using piston pin installer, pin guide J 24086-7 (violet),
and installer setting G-8 press the piston pin into the piston
and connecting rod (Fig. 6A6-52).
NOTE: The piston pin installer is a variable insertion
length tool designed to be applicable to all G M piston
assemblies. The insertion length is varied by rotating the
hub on the shaft much like adjusting a micrometer. An
alpha-numeric scale is used to determine the desired
length for a given piston pin assembly.
CAUTION: Afier installer hub bottoms on
support assembly, do not exceed 6000psipressure,
as this could cause structural damage to the tool.
4. Remove piston and connecting rod assembly from tool
and check piston for freedom of movement on piston pin.
PISTON RINGS
All compression rings are marked on the upper side of
the ring. When installing compression rings, make sure the
marked side is toward the top of the piston. The top ring is
chrome faced, or treated with molybdenum for maximum life.
The oil control rings are of three piece type, consisting
of two segments (rails) and a spacer.
1. Select rings comparable in size to the piston being
used.
2. Slip the compression ring in the cylinder bore; then
press the ring down into the cylinder bore about 1/4 inch
(below upper ring travel). Be sure ring is square with cylinder
wall.
3. Measure the space or gap between the ends of the ring
with a feeler gage (Fig. 6A6-53).
Fig.
6 A 6 - 5 3
Measuring Ring Gap
4. If the gap between the ends of the ring is below
specifications, remove the ring and try another for fit.
5. Fit each compression ring to the cylinder in which it
is going to be used.
6. If the pistons have not been cleaned and inspected as
previously outlined, do so.
7. Slip the outer surface of the top and second
compression ring into the respective piston ring groove and
roll the ring entirely around the groove (Fig. 6A6-54) to make
sure that the ring is free. If binding occurs at any point, the
cause should be determined and, if caused by ring groove,
remove by dressing with a fine cut file. If the binding is caused
by a distorted ring, check a new ring.
8. Install piston rings as follows (Fig. 6A6-55).
a. Install oil ring spacer in groove and insert anti-
rotation tang in oil hole.
b. Hold spacer ends butted and install lower steel oil ring
rail with gap properly located.
c. Install upper steel oil ring rail with gap properly
located.
d. Flex the oil ring assembly to make sure ring is free.
If binding occurs at any point, the cause should be determined
and, if caused by ring groove, remove by dressing groove with
a fine cut file. If binding is caused by a distorted ring, check
a new ring.
e. Install second compression ring expander: then ring
with gaps properly located.
f. Install top compression ring with gap properly located.
9. Proper clearance of the piston ring in its piston ring
groove is very important to provide proper ring action and
reduce wear. Therefore, when fitting new rings, the
clearances between the surfaces of the ring and groove should
be measured (Fig. 6A6-56) (See Specifications).
Advertisement
Table of Contents
