Disassembly
DISASSEMBLY OF PISTON AND CONNECTING ROD ASSEMBLYCHECK FIT BETWEEN PISTON AND PIN
Try to move the piston back and forth on the piston pin. If any movement is felt, replace the piston and pin.
REMOVE PISTON RINGS
Using a piston ring expander, remove the piston rings. Keep the rings for each cylinder separated.
DISCONNECT CONNECTING ROD FROM PISTON
(a) Using needle-nose pliers, remove the snap rings from the piston.
(b) Heat the piston in hot water to approx. 60°C (1 40°F).
(c) Using a plastic-faced hammer and brass-bar, tap the pin lightly to remove the pin from the piston.
NOTE:
The piston and pin are a matched set.
Keep the piston, pin and rings and connecting rod together for each cylinder.
INSPECTION OF PISTON AND CONNECTING ROD ASSEMBLY
1. CLEAN PISTON
(a) Scrape carbon from the piston top.
(b) Using a groove cleaning tool or broken ring, clean the ring grooves.
(c) Using solvent and brush, clean the piston thoroughly.
CAUTION: Do not use a wire brush.
2. MEASURE PISTON DIAMETER
(a) Using a micrometer, measure the piston diameter at right angles to the piston pin center line, 22 mm (0.87 in.) from the piston head.
Standard diameter: 82.90-82.95 mm
(3.2638 - 3.2658 in.)
7M-GTE 82.91-82.96 mm
(3.2642 - 3.2661 in.)
(b) Check that the difference between the cylinder diameter and the piston diameter is within specification.
Piston clearance: 7M-G 0.08-0.10 mm
(0.0031 - 0.0039 in.)
7M-GTE 0.07- 0.09 mm
(0.0028 - 0.0035 in.)
If not within specification, replace the piston and/or rebore the cylinder.
3. MEASURE CLEARANCE BETWEEN PISTON GROOVE AND PISTON RING
Using a thickness gauge, measure the clearance between the piston ring and the ring land.
Ring groove clearance: No.1 0.03-0.07 mm
(0.0012 - 0.0028 in.)
No.2 0.02-0.06 mm
(0.0008 - 0.0024 in.)
If the clearance is not within specification, replace the piston ring and/or piston.
4. MEASURE RING END GAP
(a) Insert the piston ring into the cylinder
(b) Using a piston, push the ring a little beyond the bottom of the ring travel. (110 mm (4.33 in.) from top surface of cylinder block)
(c) Using a thickness gauge, measure the end gap.
If the diameter is greater than maximum, rebore all four cylinders, or replace the cylinder block.
CHECK PISTON PIN FIT
At 60°C (140°F), the pin should be able to be pushed into the piston with your thumb.
If the pin can be installed at a lower temperature, replace the piston and pin.
INSPECT CONNECTING RODS
(a) Using a rod aligner, check the connecting rod alignment.
If the rod is bent or twisted, replace the connecting rod.
Check that the rod is not bent.
Maximum bend:
0.05 mm (0.0020 in.) per 100 mm (3.94 in.)
Check that the rod is not twisted.
Maximum twist:
0.15 mm (0.0059 in.) per 100 mm (3.94 in.)
(b) Measure the oil clearance between the rod bushing and piston pin.
Using an inside dial indicator, measure the inside diameter of the rod bushing.
Using a micrometer, measure the diameter of the piston pin.
Check that the difference between the measurements is less than oil clearance limit.
Standard oil clearance: 0.005 - 0.011 mm (0.0002 - 0.0004 in.)
Maximum oil clearance: 0.02 mm (0.0008 in.)
If the clearance is greater than maximum, replace the rod bushing.
REPLACEMENT OF ROD BUSHING
1. REMOVE ROD BUSHING
Using SST, remove the rod bushing from the connecting rod.
SST 09222-30010
2. INSTALL NEW ROD BUSHING
Using SST, install the rod bushing to the connecting rod.
SST 09222-30010
NOTE: Align the bushing oil hole with the connecting rod oil hole.
3. HONE NEW BUSHING AND CHECK PIN FIT IN CONNECTING ROD
(a) Hone the new bushing and check that the oil clearance is within standard specification.
Standard clearance: 0.005 -0.01 1 mm (0.0002 - 0.0004 in.)
(b) Check the pin fit at normal room temperature. Coat the pin with engine oil and push the pin into the rod with thumb pressure.