Piston, Connecting Rod, and Bearing Cleaning and Inspection
(LDC, LDD, LWD, L2I, L2N)
Special Tools
EN-470-B Angular Torque Wrench
For equivalent regional tools, refer to
Special Tools .
Visual Inspection And Cleaning Procedure
Connecting Rod
|
Warning:
Wear safety glasses when using compressed air in
order to prevent eye injury. |
| 1. |
Clean the connecting rods in
solvent and dry with compressed air. |
| 2. |
Inspect the connecting rod for
the following: |
| |
• |
Signs of being twisted, bent,
nicked or cracked |
| |
• |
Scratches or abrasion on the
connecting rod bearing seating surfaces |
Piston
| 1. |
Clean the piston with a
cleaning solvent. DO NOT wire brush any parts of the piston.
|
| 2. |
Clean the piston ring
grooves. |
| 3. |
Inspect the piston on the
following: |
| |
• |
Cracked ring lands, skirts or
pin bosses |
| |
• |
Eroded areas on the top of the
piston (1) |
| |
• |
Scuffed or damaged skirts
(2) |
| |
• |
Worn piston pin bores
(3) |
| 4. |
If there is any excessive
wear, replace the piston. |
| 5. |
Measure the clearance between
piston pin and piston bore. |
Piston And Connecting Rod Measurement Procedure
Piston Ring Clearance
| 1. |
Install the piston rings to
the cylinder as shown and measure the piston ring end gap. Compare
the measurements with those provided below: |
| |
• |
The upper compression ring end
gap should be 0.25 mm-0.400 mm (0.0098 in-0.0158
in) . |
| |
• |
The oil ring end gap should be
0.250 mm-0.750 mm (0.0098 in-0.0295 in) .
|
| 2. |
If the clearance is greater
than the provided specifications, the piston rings must be
replaced. |
| 3. |
Measure the piston ring side
clearance as shown. Compare the measurements with those provided
below: |
| |
• |
The upper compression ring
side clearance should be 0.025 mm-0.07 mm (0.001 in-0.0028
in) . |
| |
• |
The oil ring side clearance
should be 0.04 mm-0.12 mm (0.0016 in-0.0047 in)
. |
| 4. |
If the clearance is greater
than the provided specifications, replace the piston rings.
|
| 5. |
If the clearance is still too
great, replace the pistons. |
Connecting Rod Bearing Clearance (With Micrometer Gauge
Internal Measuring Device)
| 1. |
Install the connecting
bearings and the connecting rod bearing caps. |
| 2. |
Tighten the connecting rod
bearing cap bolts in the following sequence: |
|
Note: The old bolts can be
reused for the measuring procedure.
|
| |
2.1 |
Tighten the connecting rod
bearing cap bolts to 10 N·m (89 lb in)
. |
| |
2.2 |
Tighten the bolts to an
additional 60° , using EN-470-B
wrench . |
| |
2.3 |
Tighten the bolts to an
additional 15° , using EN-470-B
wrench . |
| 3. |
Measure the connecting rod
bearing diameters at 3 points as shown (1). Use a internal
measuring device. |
| 4. |
Calculate the average
connecting rod inner diameter. |
| |
Formula: 1. result + 2. result + 3. result / 3 |
| 5. |
Measure the connecting rod
journal diameter at 2 points between 1 and 3 and between 2 and 4.
Use a micrometer gauge. |
| 6. |
Calculate the average
connecting rod journal diameter. |
| |
Formula: 1. result + 2. result / 2. |
| 7. |
Subtract the average
connecting rod journal diameter from the average connecting rod
bearing diameter in order to determine the connecting rod bearing
clearance. |
| |
The clearance should be 0.013 mm-0.061 mm (0.0005
in-0.0024 in) . |
|
