Opel Frontera UBS. Manual - part 390

ENGINE MECHANICAL 6A – 33

2) Tighten the timing gear case bolt together with

the timing gear case gasket to the specified
torque.

19 (1.9/14)

N·m(kg·m/lb·ft)

3) Cut away the gasket protruding above the fitting

surfaces (as shown in the illustration).

4.

Crankshaft Front Oil Seal

•

Use the installer to install the front oil seal 1 to
the gear case cover 2.

Oil Seal Installer: 5-8840-2061-0

Note the oil seal installation depth 3 shown in
the illustration.

Depth 3 = 1 mm (0.0394 in.)

3.

Crankshaft Timing Gear

Use the crankshaft timing gear installer 1 to install the
timing gear 2.
The crankshaft timing mark (“X – X”) must be facing
outward.
Crankshaft Timing Gear Installer: 5-8522-0024-0

2.

Camshaft Timing Gear

•

Tighten the fixing bolt to the specified torque.

64 (6.5/47)

N·m(kg·m/lb·ft)

1.

Cylinder Head

•

Refer to “Cylinder head” in Section 6A2.

6A – 34 ENGINE MECHANICAL

PISTON AND CONNECTING ROD

DISASSEMBLY

1.

Cylinder Head Assembly

•

Refer to “Cylinder head” in Section 6A2.

2.

Crankcase Assembly

•

Refer to “Crankcase” in Section 6A2

3.

Oil Pump Assembly

4.

Connecting Rod Bearing Cap

5.

Piston and Connecting Rod

•

Remove carbon deposits from the upper portion
of the cylinder wall with a scraper before
removing the piston and connecting rod

ENGINE MECHANICAL 6A – 35

6.

Piston Ring

Remove the piston rings with a piston ring expander.
Arrange the removed piston rings in the cylinder
number order.

7.

Piston Pin Snap Ring

•

Use a pair of pliers to remove the piston pin snap
rings

8.

Piston Pin

NOTE:

Keep the parts removed from each cylinder separate.  All
parts must be reinstalled in their original positions.

9.

Piston

10. Connecting Rod

INSPECTION AND REPAIR

PISTON AND PISTON RING

Pistons

Carefully clean away all the carbon adhering to the piston
head and the piston ring grooves.

NOTE:

Never use a wire brush to clean the pistons.  Damage will
result.
Visually check each piston for cracking, scoring, and other
signs of excessive wear.
If any of the above conditions are present, the piston
must be replaced.

Piston Diameter

1.

Measure the piston outside diameter with micrometer
at the piston grading position.

71.00 (2.7974)

mm(in)

Piston Grading Position

6A – 36 ENGINE MECHANICAL

Piston rings

Any worn or damaged part discovered during engine
overhaul must replaced with a new one.

1.

Ring end gap measurement

•

Insert the piston ring into the bore.

Grade Mark

Piston Outside Diameter
Following are installed piston grade from factory.

Outside Diameter

Factory

Grade

Service Part

Grade

Outside Diameter

A

B

C

D

95.365 – 95.374 (3.7545 – 3.7549)

95.375 – 95.384 (3.7549 – 3.7553)

95.385 – 95.394 (3.7553 – 3.7557)

95.395 – 95.404 (3.7557 – 3.7561)

95.369 – 95.384

(3.7547 – 3.7553)

95.385 – 95.400

(3.7553 – 3.7559)

A and B

C and D

AX

CX

mm (in)

Method of selection grade for piston service part.

mm (in)

Grade Mark

Inside Diameter

A

B

C

D

95.425 – 95.440 (3.7569 – 3.7575)

95.441 – 95.450 (3.7575 – 3.7579)

95.451 – 95.460 (3.7579 – 3.7583)

95.461 – 95.475 (3.7583 – 3.7589)

Cylinder Liner Bore Diameter
Following are installed cylinder liner bore grade from factory.

Factory

Grade

Service Part

Grade

Outside Diameter

95.435 – 95.450

(3.7573 – 3.7579)

95.451 – 95.466

(3.7579 – 3.7585)

A and B

C and D

AX

CX

mm (in)

Method of selection grade for cylinder liner service part.

mm (in)

The grading position for piston outside diameter is
represented by the Grade mark as shown in Figure.
Measure the cylinder bore inside diameter (refer to
“Inspection of the Cylinder Block” in this Section).
If the piston clearance does not conform to the specified
valve, the pistons and/or cylinder liners most be replaced.

0.051 – 0.066 (0.0020 – 0.0026)

mm(in)

Piston Clearance