height ISUZU TF SERIES 2004 User Guide

ENGINE MECHANICAL 6A – 67













Valve Spring Free Height
Use a vernier caliper to measure the valve spring free height.
If the measured value is less than the specified limit, the valve
spring must be replaced.


Spring Free Height mm (in)
Standard Limit
4JA1T (L)
4JA1TC,
4JH1TC Single spring 48.0 (1.89) 47.1 (1.85)
















Valve Spring Squareness
Use a surface plate and a square to measure the valve spring
squareness.
If the measured value exceeds the specified limit, the valve
spring must be replaced.


Spring Squareness mm (in)
Limit
4JA1T (L)
4JA1TC,
4JH1TC Single spring 1.7 (0.070)

















Valve Spring Tension
Use a spring tester to measure the valve spring tension.
If the measured value is less than the specified limit, the valve
spring must be replaced.


Valve Spring Tension N (kg/lb)
Compressed
Height Standard Limit
4JA1T (L)
4JA1TC,
4JH1TCSingle
spring38.9mm
(1.53in) 296.0
(30.2/66.4) 257.7
(26.3/57.9)

011LX024
014RY00025
011LX026

ENGINE MECHANICAL 6A – 69
3. Check that the rocker arm oil port is free of obstructions.
If necessary, use compressed air to clean the rocker arm
oil port.




Rocker Arm Correction
Inspect the rocker arm valve stem contact surfaces for step
wear (1) and scoring (2).
If the contact surfaces have light step wear or scoring, they
may be honed with an oil stone.
If the step wear or scoring is severe, the rocker arm must be
replaced.



CYLINDER BODY
Cylinder Body Upper Face Warpage
1. Remove the cylinder body dowel.
2. Remove the cylinder liner.
Refer to "Cylinder Liner Replacement".
















3. Use a straight edge (1) and a feeler gauge (2) to measure
the four sides and the two diagonals of the cylinder body
upper face.
If the measured values exceeds the limit, the cylinder body
must be replaced.


Cylinder Body Upper Face Warpage mm (in)
Standard Limit
0.05 (0.002) or less 0.20 (0.008)


Cylinder Body Height (H) (Reference) mm (in)
Standard
4JA1T(L), 4JA1TC : 244.945-245.055 (9.6435-9.6478)
4JH1TC : 269.945-270.055 (10.6277-10.6320)
4. Reinstall the cylinder liner.
Refer to "Cylinder Liner Replacement".
5. Reinstall the cylinder body dowel.


014RY00024
012R100001
012RY00009014RY00023

6A – 70 ENGINE MECHANICAL





















Cylinder Liner Bore Measurement
Use a cylinder indicator to measure the cylinder bore at
measuring point (1) in the thrust (2-2) and axial (3-3) directions
of the crankshaft.
Measuring Point (1): 20 mm (0.79 in)
If the measured value exceeds the specified limit, the cylinder
liner must be replaced.


Cylinder Liner Bore mm (in)
Standard Limit
4JA1T(L), 4JA1TC 93.00 (3.6614) 93.08 (3.6646)
4JH1TC 95.40 (3.7559) 95.48 (3.7590)
NOTE:
The inside of the dry type cylinder liner is chrome
plated. It cannot be rebored or honed.
If the inside of the cylinder liner is scored or
scorched, the cylinder liner must be replaced.




















Cylinder Liner Projection Inspection
1. Hold a straight edge along the top edge of the cylinder liner
to be measured.
2. Use a feeler gauge to measure each cylinder liner
projection.


Cylinder Liner Projection mm (in)
Standard
0-0.1 (0-0.004)
The difference in the cylinder liner projection height
between any two adjacent cylinders must not exceed 0.03
mm (0.0012 in).













Cylinder Liner Replacement
Cylinder Liner Removal
1. Insert the cylinder liner remover (1) into the cylinder body
(from the lower side of the cylinder body) until it makes firm
contact with the cylinder liner.
Cylinder Liner Remover : 5-8840-2039-0 (4JA1L/TC)
: 5-8840-2304-0 (4JH1TC)
2. Use a bench press (2) to slowly force the cylinder liner
from the cylinder body.


NOTE:
Take care not to damage the cylinder body upper face
during the cylinder liner removal procedure.
3. Measure the cylinder body upper face warpage.
Refer to "Cylinder Body Upper Face Warpage".
012RY00010
012LX016
012RY00012

ENGINE MECHANICAL 6A – 77



CAMSHAFT
Visually inspect the journals, the cams, the oil pump drive gear,
and the camshaft bearings for excessive wear and damage.
The camshaft and the camshaft bearings must be replaced if
these conditions are discovered during inspection.














Camshaft Journal Diameter
Use a micrometer to measure each camshaft journal diameter
in two directions (1 and 2). If the measured value is less than
the specified limit, the camshaft must be replaced.


Camshaft Journal Diameter mm (in)
Standard Limit
49.945 - 49.975
(1.9663 - 1.9675) 49.60 (1.953)














Cam Height
Measure the cam height (H) with a micrometer. If the
measured value is less than the specified limit, the camshaft
must be replaced.


Cam Height (H) mm (in)
Standard Limit
42.016 (1.6542) 41.65 (1.640)



















Camshaft Run-Out
1. Mount the camshaft on V-blocks.
2. Measure the run-out with a dial indicator.
If the measured value exceeds the specified limit, the
camshaft must be replaced.


Camshaft Run-Out mm (in)
Standard Limit
0.02 (0.0008) 0.10 (0.004)

014RY00032
014RY00033
014LX092

6A-26 ENGINE MECHANICAL (6VE1 3.5L)
Exhaust Manifold LH
Removal
1. Disconnect battery ground cable.
2. Disconnect O
2 sensor connector.
3. Remove torsion bar. Refer to removal procedure in
Front Suspension section.
4. Remove exhaust front pipe three stud nuts from
exhaust side and two nuts from rear end o
f
exhaust front pipe.




RTW36FSH000201
5. Remove heat protector two fixing bolts then the
heat protector.
6. Remove a bolt on engine LH side for ai
r
conditioner (A/C) compressor bracket and loosen
two bolts for A/C compressor then move A/C
compressor to front side.
7. Remove exhaust manifold eight fixing nuts and
remove exhaust manifold from the engine.
Installation
1. Install exhaust manifold and tighten exhaust
manifold fixing nuts to the specified torque with
new nuts.
Torque: 52 N




m (5.3 kg




m/38 lb ft)
2. Install heat protector.
3. Install exhaust front pipe and tighten three stud
nuts and two nuts to the specified torque.
Torque:
Stud nuts: 67 N




m (6.8 kg




m/49 lb ft)
Nuts: 43 N




m (4.4 kg




m/32 lb ft)




RTW36FSH000201
4. Install the torsion bar and readjust the vehicle
height. Refer to installation and vehicle heigh
t
adjustment procedure for front suspension.
5. Set A/C compressor to normal position and tighten
two bolts and a bolt to the specified torque.
Torque : 40 N




m (4.1 kg




m/30 lb ft)
6. Reconnect O
2 sensor connector.
7. Install air cleaner duct assembly.

ENGINE MECHANICAL (6VE1 3.5L) 6A-53
Disassembly
NOTE:

During disassembly, be sure that the valve train
components are kept together and identified so
that they can be reinstalled in their original
locations.

Before removing the cylinder head from the engine
and before disassembling the valve mechanism,
perform a compression test and note the results.
1. Remove camshaft drive gear pulley fixing bolt (3),
then pulley (4).
2. Remove camshaft bracket fixing bolt (5), camshaf
t
bracket (6), then camshaft exhaust (7), and intake
side (8).
3. Remove tappet with shim (11).
4. Use the 5884024460 valve spring compresso
r
and 5884025470 valve spring compressor
adapter to remove the split collar (12), valve spring
with upper seat (13) and valve (14).



014RW042
5. Remove spark plug (1).
CAUTION: Do not remove the spark plugs when the
head and plugs are hot. Clean dirt and debris from
spark plug recess areas before removal.
Clean
Cylinder head
Carefully remove all varnish, soot and carbon from the
bare metal. Do not use a motorized wire brush on any
gasket sealing surface.


Inspection and Repair
1. Cylinder head gasket and mating surfaces for
leaks, corrosion and blow-by. If the gasket has
failed, determine the cause.
Insufficient torque on head bolts
Improper installation
Loose or warped cylinder head
Missing dowel pins
Warped case surface
2. Cylinder head for cracks, especially between valve
seats and in the exhaust ports.
3. Cylinder head deck for corrosion, sand particles in
head and porosity.
CAUTION:

  Do not attempt to weld the cylinder head.
Replace it.

  Do not reuse cylinder head bolts.
4. Cylinder head deck, common chamber and
exhaust manifold mating surfaces for flatness.
These surfaces may be reconditioned by milling. I
f
the surfaces are “out of flat" by more than
specification, the surface should be ground to
within specifications. Replace the head if i
t
requires machining beyond the repairable limit.
Head surface and manifold surface
Standard: 0.05 mm (0.002 in) or less
Warpage limit: 0.2 mm (0.0079 in)
Maximum Repairable limit: 0.2 mm (0.0079 in)
Head height
Standard height : 133.2 mm (5.2441 in)
Warpage limit : 0.2 mm (0.0079 in)
Maximum Repairable limit : 133.0 mm (5.2362
in)



011RW019

ENGINE MECHANICAL (6VE1 3.5L) 6A-57
Disassembly
1. Remove camshaft bracket fixing bolts (1).
2. Remove camshaft assembly (intake).
3. Remove camshaft assembly (Exhaust side).
4. Remove shim (4) and tappet (5).
5. Use the 5
8840
2446
0 valve spring compresso
r
and 5
8840
2547
0 valve spring compressor
adapter to remove split collar.



014RW042
6. Remove valve spring.
7. Remove valve.
8. Remove oil controller and spring lower seat.
9. Remove the valve guide using the 5
8840
2442
0
valve guide replacer.
Inspection and Repair
Valve Spring
CAUTION: Visually inspect the valve springs and
replace them if damage or abnormal wear is
evident.
1. Measure the free height of the springs. The
springs must be replaced if the free height is belo
w
the specified limit.
Standard: 44.6 mm (1.756 in)
Limit: 43.6 mm (1.717 in)





014RS004
2. Measure the valve spring squareness with a steel
square and replace the valve springs if the
measured value exceeds the specified limit.
Limit: 2 mm (0.079 in)


014RS005
3. Using a spring tester to compress the springs to
the installed height, measure the compressed
spring tension, and replace the springs if the
measured tension is below the specified limit.
At installed height: 35.0 mm (1.38 in)
Standard: 196 N (44 lb)
Limit: Less than 181 N (41 lb)

ENGINE MECHANICAL (6VE1 3.5L) 6A-59
Valve Guide Replacement
1. Using Valve guide replacer: 5
8840
2442
0,
drive out the valve guide from the combustion
chamber side.


014RS008
2. Apply engine oil to the outside of the valve guide.
Using valve guide replacer 5
8840
2442
0,
drive in a new valve guide from the camshaft side,
and check the valve guide height.
Valve guide upper end height: 13.0 mm (0.5118
in)
(Measured from the cylinder head upper face)





014RW046
3. Check the clearance. If the clearance is less than
the specified value, ream the inside diameter o
f
valve guide. Using a sharp 6 mm reamer, ream the
valve guide to obtain the specified clearance.

Valve Seat
1. Measure the protrusion of the valve stem when a
new valve is installed in the cylinder head. If the
protrusion of the valve stem exceeds the limit,
replace the valve seat insert or the cylinder head
assembly.
Protrusion of valve stem
Intake
Standard: 39.32 mm (1.5480 in)
Limit: 39.47 mm (1.5539 in)
Exhaust
Standard: 39.30 mm (1.5472 in)
Limit: 39.45 mm (1.5531 in)





014RW047

ENGINE MECHANICAL (6VE1 3.5L) 6A-65



014RW060
2. Remove twenty fixing bolts from inlet and exhaust
camshaft bracket on one side bank, then camshaft
brackets (2).








014RW027
3. Remove camshaft assembly (3), (4).
4. Remove three fixing bolts (7) from camshaft drive
gear retainer (8), then camshaft drive gea
r
assembly.

Inspection and Repair
1. Use a micrometer to measure the cam lobe height
and uneven wear. Replace the camshaft if eithe
r
the lobe height or the uneven wear exceeds the
specified limit.
Lobe height: 44.709 mm (1.7602 in)
Uneven wear: 0.05 mm (0.0020 in)

014RW043
2. Use a micrometer to measure the diameter and
the uneven wear of the camshaft journals.
Replace the camshaft if the diameter or the
uneven wear exceeds the specified limit.
Journal Diameter
Standard: 25.972 mm




25.993 mm (1.0225
in




1.0233 in)
Limit: 25.8 mm (1.0157 in)
Uneven wear: 0.05 mm (0.0020 in)





014RS023

ENGINE MECHANICAL (C24SE) 6A-39







Camshaft Housing, Check for Plane Surface
Clean
Sealing surfaces.

Inspection
Check length and width of sealing surface for deformation and
diagnosis for warpage and use straight edge feeler gauge.

Measure
Height of camshaft housing (sealing surface to sealing
surface).
Dimension I: (74.0 mm)



Cylinder Head, Removal and Installation
Important
Only remove cylinder head with engine cold (room
temperature).




Removal
1. Remove the alternator, power steering and V-belts.



Removal
2. Loosen the fastening bolts from alternator.
3. Loosen the lower alternator fastening bolt by swinging
the alternator to the rear.



Removal
4. Remove the front toothed belt cover.
5. Remove the toothed belt from camshaft pulley.
See operation "Timing Check and Adjust".