Chevrolet 1991 Light Duty Truck Repair Manual page 412

6A2-20 2JQL V6 ENGINE
PISTON AND CONNECTING
ROD INSTALLATION
CONNECTING ROD BEARING SELECTION
Connecting rod bearings are of the precision insert
type and do not use shims for adjustment. DO NOT
< Tp ENGINE LEFT ENGINE FRONT
A. Oil Ring Rail Gaps
B. 2nd Compression Ring Gap
C Notch In Piston
D. Oil Ring Spacer Gap
(Tang In Hole Or Slot With Arc)
E. Top Compression Ring Gap
Figure 34— Piston Ring End Gap Locations
Figure 36—Measuring the Connecting Rod Side
Clearance (Typical)
5
ENGINE RIGHT
FILE RODS OR ROD CAPS. If clearances are exces­
sive install a new bearing. Service bearings are avail­
able in standard size and 0.013mm and 0.026mm
undersize for use with new and used standard size
crankshafts.
Install or Connect
B
Tool Required:
J 8037 Ring Compressor
• Lubricate the cylinder walls lightly with engine oil.
• Make sure the piston is installed in the proper cyl­
inder with the notch forward.
1. Connecting rod bearing inserts.
• Be certain that the inserts are of the proper
size.
• Install the inserts in the connecting rod and
connecting rod cap.
2 Piston and connecting rod into the proper bore.
• Install thread protectors over the threads of the
rod studs to prevent damage to the bearing
journal and rod studs.
• Locate the ring end gaps as shown in figure
34.
• Lubricate the piston and rings with engine oil.
• Without disturbing the ring end gap location,
install J 8037 over the piston.
• Use a hammer handle to tap the piston down
into its matching bore (figure 35).
— The notch in the piston crown must face the
front of the engine.
• While tapping the piston into its bore, guide the
connecting rod into position on the crankpin.
Hold the ring compressor against the block
until all rings have entered the cylinder bore.
Important
• Each connecting rod and bearing cap should
be marked, beginning at the front of the
engine. Cylinders 2, 4 and 6 are the left bank
and, 1, 3 and 5 are the right bank. The num­
bers on the connecting rod and bearing cap
must be on the same bank when reinstalling
them into the cylinder bore. If a connecting rod
is ever moved from one block or cylinder to
another, new connecting rod bearings should
be fitted and the connecting rod should be
numbered to correspond with the new cylinder
number.
3. Connecting rod cap with bearing insert.
| ^ | | Measure
• Connecting rod bearing clearance. Refer to
GENERAL ENGINE MECHANICAL (SEC.6A).
Q Tighten
• Connecting rod cap nuts to 53 N-m (39 ft. lbs.).
Measure
• Connecting rod side clearance (figure 36). Clear­
ance is 0.16 to 0.64mm.