jcb 3DX Super User manual

SERVICE MANUAL
BACKHOE LOADER
3DX Super, 3DX Xtra, 4DX
EN - 9823/0000 - ISSUE 1 - 01/2018
This manual contains original instructions, verified by
the manufacturer (or their authorized representative).
Copyright 2018 © JCB SERVICE
All rights reserved. No part of this publication may
be reproduced, stored in a retrieval system, or
transmitted in any form or by any other means,
electronic, mechanical, photocopying or otherwise,
without prior permission from JCB SERVICE.
www.jcb.com
Foreword
The Operator's Manual
You and others can be killed or seriously injured
if you operate or maintain the machine without
first studying the Operator's Manual. You must
understand and follow the instructions in the
Operator's Manual. If you do not understand
anything, ask your employer or JCB dealer to
explain it.
Do not operate the machine without an Operator's
Manual, or if there is anything on the machine you
do not understand.
Treat the Operator's Manual as part of the machine.
Keep it clean and in good condition. Replace the
Operator's Manual immediately if it is lost, damaged
or becomes unreadable.
Contents
01 - Machine
03 - Attachments, Couplings and Load
Handling
06 - Body and Framework
09 - Operator Station
15 - Engine
18 - Fuel and Exhaust System
21 - Cooling System
24 - Brake System
25 - Steering System
27 - Driveline
30 - Hydraulic System
33 - Electrical System
72 - Fasteners and Fixings
75 - Consumable Products
78 - After Sales

15 - Engine
42 - Rocker and Fittings
00 - General
15 - 155 9823/0000-1 15 - 155
00 - General
Introduction .................................................. 15-155
Technical Data ............................................. 15-156
Component Identification ............................. 15-157
Operation ..................................................... 15-158
Check (Condition) ........................................ 15-159
Remove and Install ..................................... 15-160
Disassemble and Assemble ........................ 15-163
Introduction
The rocker assembly is an indirect valve actuating
system consisting of rocker arms and a shaft.
The rocker arm is an oscillating lever that conveys
radial movement from the cam lobe into linear
movement at the poppet valve to open it. One end is
raised and lowered by a rotating lobe of the camshaft
via a tappet and push rod while the other end acts
on the bridge piece which is connected to the valve
stem.

15 - Engine
42 - Rocker and Fittings
00 - General
15 - 156 9823/0000-1 15 - 156
Technical Data
(For: JCB Tier 2/3 Mech Engine 4 Cyl)
Table 59. Rocker Levers, Rocker Shafts and Tappets Data
Valve tip clearances (measured cold):
Inlet: 0.19–0.27mm- SA, SB, SC
Exhaust: 0.56–0.64mm
Inlet: 0.35mm- SD, SF
Exhaust: 0.56–0.64mm
Rocker lever bore diameter
- min 26.046mm
- max 26.129mm
Rocker shaft diameter
- min 26mm
- max 26.021mm
Tappets stem diameter
- min 19.987mm
- max 19.975mm
Tappet bore diameter
- min 20mm
- max 20.021mm
Tappet height (maximum) 55.25mm

15 - Engine
42 - Rocker and Fittings
00 - General
15 - 157 9823/0000-1 15 - 157
Component Identification
(For: JCB Tier 2/3 Mech Engine 4 Cyl)
Figure 200.
743830
4
7
4
5
4
4
4
4
4
1
6
2
3
2
2
2
2
2
2
1Rocker shaft assembly 2Rocker shaft fixing bolts (x7)
3Rocker shaft - oil feed pedestal fixing bolt (x1) 4Pedestals (x7)
5Oil feed pedestal (x1) 6Bridge pieces (x8)
7Push rods (x8)

15 - Engine
42 - Rocker and Fittings
00 - General
15 - 158 9823/0000-1 15 - 158
Operation
When the camshaft lobe raises the outside of the
rocker arm, the inside presses down on the valve
stem to open the valve. When the outside of the
rocker arm is permitted to return due to the camshafts
rotation, the inside rises to allow the valve spring to
close the valve.
Figure 201.
1Oil feed from main gallery 2Small transfer gallery
3Shaft pedestal 4Rocker shaft fixing bolt hole
5Centre rocker shaft drilling 6Cross drillings
7Rocker pivot bushes 8Cross drilling
9Groove
Lubrication
Oil is fed from the main gallery via a drilling which
passes up through the crankcase and the cylinder
head to a small transfer gallery under the rocker
shaft pedestal. The oversize rocker shaft fixing bolt
hole allows oil to pass into a drilling in the centre of
the rocker shaft. Further cross drillings transfer oil
to each of the rocker pivot bushes. A cross drilling
in each rocker transfers oil to the top of the rocker
where it flows by gravity along a groove to the rocker
tip.

15 - Engine
42 - Rocker and Fittings
00 - General
15 - 159 9823/0000-1 15 - 159
Check (Condition)
1. Check the rocker shaft and rocker bushings for
signs of damage and excessive wear. Measure
the rocker shaft diameter and rocker bearing
bushes to confirm they are within service limits.
Refer to Technical Data. Note: The rocker
bearing bushes are not renewable. If a rocker
bearing bush is damaged or worn the rocker
must be renewed as a complete assembly.
Refer to: PIL 15-42.
2. Make sure that all oil-ways and cross drillings in
the rocker shaft, rocker arms and pedestals are
clear and free from debris. Use an air line to blow
through cross drillings.

15 - Engine
42 - Rocker and Fittings
00 - General
15 - 160 9823/0000-1 15 - 160
Remove and Install
(For: JCB Tier 2/3 Mech Engine 4 Cyl)
Before Removal
1. Make sure that the engine is safe to work on. If
the engine has been running, let it cool before
you start the service work.
2. Get access to the engine.
3. Disconnect and remove the fuel pipes from the
fuel injectors, refer to Fuel pipes (PIL 18-96).
4. Remove the rocker cover, refer to (PIL 15-42).
Figure 202.
743830
4
7
4
5
4
4
4
4
4
1
6
2
3
2
2
2
2
2
2
1Rocker shaft assembly 2Rocker shaft fixing bolts (x7)
3Rocker shaft - oil feed pedestal fixing bolt (x1) 4Pedestals (x7)

15 - Engine
42 - Rocker and Fittings
00 - General
15 - 161 9823/0000-1 15 - 161
5Oil feed pedestal (x1) 6Bridge pieces (x8)
7Push rods (x8)

15 - Engine
42 - Rocker and Fittings
00 - General
15 - 162 9823/0000-1 15 - 162
Remove
1. Remove the rocker shaft fixing bolts. DO NOT
withdraw the bolts. Lift the rocker shaft assembly
from the cylinder head complete with pedestals
still attached. Important: Keep all pedestals and
fixing bolts in their original positions.
2. Lift off the bridge pieces from the pairs of inlet
and exhaust valves.
3. Withdraw the push rods from the cylinder block.
Before Installation
1. Make sure that all items are clean and free from
damage and corrosion. Refer to Check Condition
(PIL 15-42).
2. Make sure that all oil-ways and cross drillings in
the cylinder head, rocker shaft and pedestals are
clear and free from debris. Use an air line to blow
through the cross drillings.
Install
1. The installation procedure is the opposite of the
removal procedure. Additionally do the following
steps.
2. Use a suitable degreasing agent to clean the top
of the cylinder head.
3. Install the bridge pieces on to the pairs of inlet
and exhaust valves in the cylinder head.
4. Insert the push rods into the cylinder block. Make
sure that they engage with the camshaft tappets.
5. Install the rocker shaft assembly into the cylinder
head. Make sure that the pedestals are located in
their original positions. Note the position of the oil
feed pedestal and the longer bolt. Make sure that
the push rods engage with the tappet adjusters
and that the rockers are located over the bridge
pieces.
6. Tighten the bolts to the correct torque value.
After Installation
1. Measure and adjust the valve clearances, refer
to (PIL 15-30).
Table 60. Torque Values
Item Nm
2 24
3 24

15 - Engine
42 - Rocker and Fittings
00 - General
15 - 163 9823/0000-1 15 - 163
Disassemble and Assemble
(For: JCB Tier 2/3 Mech Engine 4 Cyl)
Before Disassembly
1. Remove the rocker cover. Refer to (PIL 15-42).
2. Remove the rocker assembly. Refer to (PIL
15-42).
Figure 203.
2
3
1
4
5
5
7
8
6
4
4
4
4
2
2
2
2
1Rocker shaft 2Rocker shaft fixing bolts (x7)
3Rocker shaft - Oil feed pedestal fixing bolt (x1) 4Pedestals (x7)
5Oil feed pedestal (x1) 6Rockers - inlet (x4)
7Rockers - exhaust (x4) 8Wave washers (x8)

15 - Engine
42 - Rocker and Fittings
00 - General
15 - 164 9823/0000-1 15 - 164
Disassemble
1. Lift out the rocker shaft fixing bolts, then slide
the pedestals, rockers and wave washers off the
rocker shaft as shown. Label the pedestals and
rockers to make sure that they are installed in the
correct positions on assembly.
2. Check the rocker shaft and rocker bushings for
signs of damage and excessive wear. Refer to
Check (Condition) (PIL 15-42).
Assemble
1. The assembly procedure is the opposite of
the disassemble procedure. Additionally do the
following steps.
2. Lubricate the rocker shaft and rocker bearing
bushes with clean engine oil.
3. Make sure that the rockers and pedestals are
installed in their original positions along the
rocker shaft. Note the position of the oil feed
pedestal.
4. Insert the rocker shaft fixing bolts to hold the
rockers and pedestals loosely in position before
fitting the assembly into the cylinder head. Note
the position of the longer bolt.
After Assembly
1. Install the rocker assembly. Refer to (PIL 15-42).
2. Install the rocker cover. Refer to (PIL 15-42).

15 - Engine
42 - Rocker and Fittings
06 - Rocker Cover
15 - 165 9823/0000-1 15 - 165
06 - Rocker Cover
Remove and Install
(For: JCB Tier 2/3 Mech Engine 4 Cyl)
Before Removal
1. Make sure that the engine is safe to work on. If
the engine has been running, let it cool before
you start the service work.
2. Clean the top of the rocker cover and around
the fuel injectors. Refer to Engine - Clean (PIL
15-00).
3. Disconnect and remove the fuel pipes from the
injectors.
Refer to: PIL 18-96.
3.1. Caps for blanking the open ends of the fuel
pipes are supplied with the rocker cover
gasket kit.
Figure 204.
3
6
8
5
1
2
4
7
1Rocker cover 2Bolts (x6)
3Pipe stub (breather hose) 4Turbocharger outlet (Turbocharged engines
only) Injector seals
5Inlet manifold 6Gasket
7Injector sleeves/covers 8Rocker cover injector seals

15 - Engine
42 - Rocker and Fittings
06 - Rocker Cover
15 - 166 9823/0000-1 15 - 166
Remove
1. Get access to the engine.
2. Disconnect the breather hose from the pipe stub.
3. Disconnect the air hose from the turbocharger
outlet and inlet manifold. Remove the hose. (For
Turbocharged Engine Only)
4. Remove the bolts and lift the rocker cover from
the cylinder head.
5. Discard the gasket.
6. Put the sleeves/covers over the injectors.
7. The rocker cover injector seals must be replaced.
Refer to Injector seals (PIL 18-18).
Install
1. The installation procedure is the opposite of the
removal procedure. Additionally do the following
steps.
2. Remove all oil and sludge contamination from
inside the rocker chamber.
3. Install new the injector seals. Refer to Injector
seals (PIL 18-18).
4. Install new the rocker cover gasket.
5. Prevent damage to the seals. Put sleeves/covers
on the four injectors. Apply a rubber lubricant to
the seals and then install the rocker cover.
6. Tighten the bolts to the correct torque value.
7. Remove the sleeves/covers.
After Installation
1. Connect the fuel pipes to the injectors.
Refer to: PIL 18-96.
2. Start the engine and check for oil and fuel leaks.
Table 61. Torque Values
Item Nm
B 24

15 - Engine
42 - Rocker and Fittings
21 - Tappet
15 - 169 9823/0000-1 15 - 169
21 - Tappet
Remove and Install
(For: JCB Tier 2/3 Mech Engine 4 Cyl)
Special Tools
Description Part No. Qty.
Crankshaft /
Camshaft Timing Pin
(444/448/672 Engine)
892/01148 1
Before Removal
1. Drain the oil from the engine.
2. Disconnect and remove the fuel pipes from the
injectors.
Refer to: PIL 18-96.
3. Remove the rocker cover.
Refer to: PIL 15-42-06.
4. Remove the fuel injection pump.
Refer to: PIL 18-18-15.
5. Remove the rocker assembly and push rods.
Refer to: PIL 15-42-09.
6. Remove the starter motor.
Refer to: PIL 15-75-00.
7. Remove the oil sump.
Refer to: PIL 15-45-00.
8. Remove the flywheel.
Refer to: PIL 15-54-00.
9. Remove the flywheel housing.
Refer to: PIL 15-54-03.
10. Rotate the crankshaft until the camshaft timing
pin can be inserted through the gear and into the
aligning hole in the rear gear case.
Special Tool: Crankshaft / Camshaft Timing Pin
(444/448/672 Engine) (Qty.: 1)
Figure 205.
A
ATiming pin - camshaft
11. Remove the taper blanking plug and insert
crankshaft locking pin. The camshaft and
crankshaft locking pins must be in position to lock
the crankshaft and camshaft before removing the
camshaft assembly.
Special Tool: Crankshaft / Camshaft Timing Pin
(444/448/672 Engine) (Qty.: 1)
Figure 206.
B
C
BTiming pin- crankshaft
CBlanking plug
12. Remove the fuel injection pump drive gear.
Refer to: PIL 15-51-09.
Removal
The engine must be inverted. DO NOT attempt
to remove the camshaft and its drive gears with
the engine upright. The tappets and push rods will
fall into the engine and further dismantling will be
required to retrieve them.
1. Remove the camshaft timing pin.
Special Tool: Crankshaft / Camshaft Timing Pin
(444/448/672 Engine) (Qty.: 1)
2. Carefully withdraw the camshaft and gear
assembly from the crankcase. Make sure you
fully support the camshaft to prevent the lobes
contacting the bearing surfaces in the crankcase.
The bearing surfaces can easily be damaged by
the sharp hard edges on the cam lobes.

15 - Engine
42 - Rocker and Fittings
21 - Tappet
15 - 170 9823/0000-1 15 - 170
Figure 207.
A
D
ATiming pin - camshaft
DCamshaft and drive gear
3. Access the tappets through the apertures in
the crankcase bedplate next to the crankshaft.
Lift out the tappets from the crankcase using a
suitable magnetic probe. Label the tappets to
ensure replacement in their original positions.
Figure 208.
E
F
E
ETappet (8 off)
FMagnetic probe
Inspection
1. Inspect the camshaft gear teeth for signs of
damage or excessive wear.
2. Inspect the cam lobes for signs of excessive
wear, scoring or pitting.
3. Inspect the cam bearing surfaces for signs
of excessive wear, or scoring. Check that the
dimensions are within service limits.
4. Inspect the cam bearing surfaces inside the
crankcase for signs of excessive wear, or
scoring. Check that the dimensions are within
service limits.
5. Inspect the bearing surfaces of the tappets for
signs of excessive wear or damage. Check that
the dimensions are within service limits.
6. Inspect the tappet bores inside the crankcase for
signs of excessive wear or damage. Check that
the dimensions are within service limits.
7. If any of the camshaft bearings or lobes are worn
or damaged then the relative oil feed galleries in
the cylinder block and camshaft may be blocked.
Make sure all oil ways are clear and free from
debris.
Installation
1. Lubricate the tappets and tappet bores inside the
crankcase with clean engine oil.
2. Insert the tappets in their original positions in the
crankcase using a suitable magnetic probe.
3. Lubricate the camshaft bearing journals inside
the crankcase with clean engine oil.
4. Carefully insert the camshaft assembly into the
crankcase as shown. Support the camshaft
preventing the lobes contacting the bearing
surfaces in the crankcase. Before meshing the
camshaft gear with the crankshaft gear, rotate
the camshaft until the timing hole in the gear
aligns with the dowel hole in the gear casing.
Insert the camshaft timing pin to lock the
camshaft in this position.
After Installation
1. Note that the fuel injection pump drive gear fixing
nut is torque tightened as part of the fuel injection
pump replacement procedure.
Refer to: PIL 18-18-15.
2. In reverse order, carry out the procedures in
Before Removal.

15 - Engine
42 - Rocker and Fittings
24 - Tappet Cover
15 - 171 9823/0000-1 15 - 171
24 - Tappet Cover
Remove and Install
It is not necessary to remove the tappet covers
unless a new rocker cover is to be installed. It is
necessary to remove the tappet covers to measure
and adjust the valve clearances. Refer to Valve-
Adjust, Valve Clearances (PIL 15-30).
Remove
1. Make sure that the engine is safe to work on. If
the engine has been running, let it cool before
you start the service work.
2. Get access to the engine.
3. Clean the tappet covers and the adjacent areas
of the rocker cover. Refer to Engine - Clean.
Important: Make sure that the screws do not fall
into the engine.
4. Remove the tappet cover screws.
5. Keep the screws away from the engine.
6. Use a screwdriver in the slot to remove the tappet
covers. Make sure that dirt or debris does not fall
into the engine.
Figure 209.
B
A
E
B
B
B
B
C
D
AScrews
BTappet covers
CSlot
DRocker cover
ETappet cover seals
Install
1. The installation procedure is the opposite of the
removal procedure. Additionally do the following
steps.
2. Inspect the tappet cover seals for signs of
damage. Replace any damaged seals.
3. Install the tappet covers. Tighten the screws to
the correct torque value.
Table 62. Torque Values
Item Nm
A 9

15 - Engine
45 - Oil Sump
00 - General
15 - 173 9823/0000-1 15 - 173
00 - General
Introduction .................................................. 15-173
Component Identification ............................. 15-174
Remove and Install ..................................... 15-175
Introduction
The lubrication system distributes oil around the
engine by a system of galleries and drillings in the
crankcase and cylinder head. The oil lubricates and
seals the moving parts of the engine, reducing friction
and wear. In addition the oil plays an important role in
cooling the engine by carrying heat from the engine
to the cooler. A piston cooling jet sprays oil onto the
underside of the pistons to keep them cool, refer to
(PIL 15-36).
Oil is drawn from the oil sump by the integral oil pump
via the suction strainer. The strainer prevents any
large particles of debris passing through, which may
damage the pump.
The oil passes from the outlet side of the pump
through a relief valve which limits the maximum oil
pressure by venting oil back to the inlet side of the
pump, refer to (PIL 15-36).
From the pump the oil passes through the oil cooler
and filter, refer to (PIL 15-69 and PIL 15-21).
After cooling and filtering, the oil passes into the
main oil gallery. An oil pressure switch senses the
oil pressure. From the main gallery oil is delivered,
via drillings, to the crankshaft main bearings, rocker
assembly, camshaft and timing gears. Note that
drillings are through the crankcase and cylinder
head.
When the high pressure oil has passed through the
bearings it reverts to sump pressure and splash
lubricates the internal components such as rocker
tips, cam lobes and timing gear teeth. Gravity
drains the oil via drains into the cylinder head and
crankcase, back into the oil sump. A drain slot allows
the oil to drain from the timing case back to the oil
sump.

15 - Engine
45 - Oil Sump
00 - General
15 - 174 9823/0000-1 15 - 174
Component Identification
(For: JCB Tier 2/3 Mech Engine 4 Cyl)
Figure 210.
1Oil sump 2Suction strainer
3Oil pump 4Oil cooler
5Filter 6Camshaft - high pressure oil feed
7Crankshaft main bearings - high pressure oil
feed
8Rocker assembly - high pressure oil feed
9PTO (Power Take-Off) idler gear bearing/
timing case - high pressure oil feed
10 External high pressure oil feed connection
(crankcase) - Turbocharger (if installed)
11 Main high pressure oil feed gallery
(crankcase)
12 Oil pressure switch
Green- Oil at sump pressure Red- Oil at high pressure
Pink- Oil at lower pressure but higher than
sump pressure

15 - Engine
45 - Oil Sump
00 - General
15 - 175 9823/0000-1 15 - 175
Remove and Install
(For: JCB Tier 2/3 Mech Engine 4 Cyl)
Special Tools
Description Part No. Qty.
Template for Sealant
Oil Sump - Pressed
892/01149 1
Oil Sump Location
Dowel
892/01150 2
Template for Sealant
Oil Sump (Cast)
892/12354 1
Consumables
Description Part No. Size
Clear Silicone Sealant 4102/0901 0.31L
Before Removal
1. Make sure that the engine is safe to work on.
If the engine has been running, make sure the
engine has cooled sufficiently before you start.
2. Drain the engine oil.
Removal
1. Remove the fixing bolts and remove the oil sump
from the engine. The oil sump may be difficult to
remove due to adhesion of sealing compound.
If necessary, carefully lever the mating flanges
apart. Do not use excessive force, the oil sump
could be damaged. Be sure to retrieve the oil pick
up seal.
2. Use a gasket removal compound, carefully
remove all traces of sealing compound from the
oil sump and engine mating faces. Do not allow
the sealing compound to enter the engine.
3. Use a suitable degreasing agent to thoroughly
clean the oil sump.
Figure 211.
1Oil sump 1a Integral suction tube
1b Integral baffle plates 2Oil sump fixing bolts (x20)
3Oil pick up seal

15 - Engine
45 - Oil Sump
00 - General
15 - 176 9823/0000-1 15 - 176
Installation
1. Lightly smear the new oil pick up seal with oil and
install into the bedplate as shown.
Figure 212.
3Oil pick up seal
2. Install the two guide pins at the oil sump screw
holes in the engine.
Special Tool: Oil Sump Location Dowel (Qty.: 2)
3. Use the fixing bolts to locate the template to
the oil sump mating face. Make sure that the
template is the correct way round (note that holes
are on different centres).
Special Tool: Template for Sealant Oil Sump
(Cast) (Qty.: 1)
Special Tool: Template for Sealant Oil Sump -
Pressed (Qty.: 1)
4. Apply a bead of sealing compound around the
oil sump flange using the inside edge of the
template as a guide as shown. Note the beads
around holes.
Length/Dimension/Distance: 4mm
Consumable: Clear Silicone Sealant
5. Carefully remove the template without smudging
the sealant beads.
6. Apply a bead of sealant so as to join the sealant
beads around holes with the bead around the oil
sump flange.
Length/Dimension/Distance: 4mm
7. After applying the sealing compound, the oil
sump must be installed and the bolts torque
tightened within
Duration: 5min
Figure 213.
X
X
SHole
THole
T2 Guide pins
X4mm Bead of sealant
8. Position the oil sump with the suction tube outlet
aligned with the oil pump inlet port on the engine.
Take care not to damage the oil pick up seal when
you install the oil sump. Damage to the seal could
cause a drop in oil pressure and subsequently
damage to the engine.
9. Locate the oil sump on the guide pins on the
engine. Avoid smudging the sealant beads. DO
NOT remove the guide pins until sufficient bolts
have been installed to secure the oil sump.
10. Install the bolts and tighten the bolts to the correct
torque value. Note that the bolts are not installed
at 6 positions.
Figure 214.
2Bolts
YNo bolts to be installed at this position (x6)