Piston And Connecting Rod Installation - GMC 1990 Light Truck Repair Manual

6A3-20 4.3 LITER V-6
U
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 33—Piston Ring End Gap Locations
3. Torsional damper over the end of the stud. Align the
keyway in the torsional damper shaft with the
crankshaft key.
4. Bearing, washer and nut (figure 28).
• Turn the nut to pull the vibration damper into
place.
• Remove the tool.
5. Torsional damper bolt and washer.
Tighten
• Bolt to 95 N m (70 ft. lbs.).
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 FILE
RODS OR ROD CAPS. If clearances are excessive install
a new bearing. Service bearings are available in standard
size and 0.0014 mm undersize for use with new and used
standard size crankshafts.
Install or Connect (Figures 33 through 35)
Tools Required:
J 5239, Connecting Rod Guide Set
J 8037, Ring Compressor
• Lubricate the cylinder walls lightly with engine oil.
• Make sure the piston is installed in the matching
cylinder.
1. Connecting rod bearings.
• Be certain that the bearing inserts are of the
proper size.
• Install the bearing inserts in the connecting
rod and connecting rod cap.
• Lubricate the bearings with engine oil.
2. Piston and connecting rod to the proper bore.
• With the connecting rod cap removed, install
J 5239 onto the connecting rod studs.
ENGINE RIGHT
B-07895
Figure 34—Installing the Piston
A. Guide Rod
B. Thread Protector
Figure 35—Guiding the Connecting Rod
B-05269