Piston And Connecting Rod Assemblies - Chevrolet LIGHT DUTY TRUCK (SERIES 10-35) Service Manual

Fig. 6A 1-39~Removing C onnecting Rod & Piston Assem bly

PISTON AND CONNECTING ROD ASSEMBLIES

Removal
1. With oil pan, oil pump and cylinder head removed,
use a ridge reamer to remove any ridge and/or deposits from
the upper end of the cylinder bore.
NOTICE: Before ridge and/or deposits are removed,
turn crankshaft until piston is at the bottom of stroke
and place a cloth on top of piston to collect the cuttings.
After ridge and/or deposits are removed, turn
crankshaft until piston is at top of stroke and remove
cloth and cuttings.
2. Inspect connecting rods and connecting rod caps for
cylinder identification. If necessary, mark them.
3. Remove connecting rod cap and install Tool J-6305
(11/32") on studs. Push connecting rod and piston assembly
out of top of cylinder block (fig. 6A1-39).
It will be necessary to turn the crankshaft
NOTICE:
slightly to disconnect some of the connecting rod and
piston assemblies and push them out of the cylinder.
Disassembly
1 . Remove connecting rod bearings from connecting
rods and caps.
If connecting rod bearings are being reused,
NOTICE:
place them in a rack so they may be reinstalled in their
original rod and cap.
2. Remove piston rings by expanding and sliding them
off the pistons. Tools J-8021 (3-7/8") and J-22249 (3-15/
16") are available for this purpose.
3. Place connecting rod and piston assembly on tool
J-24086. Using an arbor press and piston pin remover, J-
FIXTURE &
SUPPORT
ASSEMBLY
J -2 4 0 8 6 -2 0
Fig. 6A1-40--Rem oving Piston Pin
24086, press the piston pin out of connecting rod and piston
(fig. 6A1-40).
Cleaning and Inspection
Connecting Rods
Wash connecting rods in cleaning solvent and dry with
compressed air.
Check for twisted or bent rods and inspect for nicks
or cracks. Replace connecting rods that are damaged.
Pistons
Clean varnish from piston skirts and pins with a
cleaning solvent. DO NOT W IR E BRUSH A N Y PART
OF THE PISTON. Clean the ring grooves with a groove
cleaner and make sure oil ring holes and slots are clean.
Inspect the piston for cracked ring lands, skirts or pin
bosses, wavy or worn ring lands, scuffed or damaged skirts,
eroded areas at top of the piston. Replace pistons that are
damaged or show signs of excessive wear.
Inspect the grooves for nicks or burrs that might cause
the rings to hang up.
Measure piston skirt (across center line of piston pin)
and check clearance as outlined under "Piston Selection".
Piston Pins
The piston pin clearance is designed to maintain
adequate clearance under all engine operating conditions.
Because of this, the piston and piston pin are a matched set
and not serviced separately.
Inspect piston pin bores and piston pins for wear.
Piston pin bores and piston pins must be free of varnish or
scuffing when being measured. The piston pin should be
IN-LINE 6 6A1-27
PRESS
PISTON PIN
REMOVER
J -2 4 0 8 6 -8
LIGH T T R U CK SER V IC E MANUAL