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

Summary

Foreword

The Operators Manual

Guidance on the importance and proper use of the Operator's Manual for safety and operational understanding.

15 - Engine

Rocker and Fittings

Details about the rocker arm system, including general information, technical data, identification, operation, and maintenance.

Rocker Cover

Procedures for removing and installing the engine's rocker cover.

21 - Tappet

Remove and Install

Instructions for removing and installing engine tappets.

Inspection

Procedures for inspecting engine tappets for wear and damage.

Installation

Steps for installing engine tappets correctly.

24 - Tappet Cover

Remove and Install

Procedures for removing and installing tappet covers for valve clearance adjustment.

45 - Oil Sump

Remove and Install

Detailed instructions for removing and installing the engine oil sump.

Installation

Steps for correctly installing the engine oil sump.

51 - Timing Gear

General

General information on engine timing gears.

Component Identification

Visual identification of engine timing gear components.

Overview

1. Engine - Rocker and Fittings (Section 15-42)
2. Important Technical Specifications (Table 59. Rocker Levers, Rocker Shafts and Tappets Data)
3. Lubrication System for Rocker and Fittings
4. Maintenance Features
5. Engine - Rocker Cover (Section 15-42-06)
6. Maintenance Features
7. Engine - Tappet (Section 15-42-21)
8. Special Tools
9. Maintenance Features
10. Engine - Tappet Cover (Section 15-42-24)
11. Maintenance Features
12. Engine - Oil Sump (Section 15-45)
13. Function Description
14. Special Tools
15. Consumables
16. Maintenance Features
17. Engine - Timing Gear (Section 15-51)
18. Function Description
19. Maintenance Features

This document is a service manual for the JCB 3DX Super, 3DX Xtra, and 4DX Backhoe Loaders, specifically focusing on the engine components. It provides detailed instructions and specifications for the maintenance, removal, installation, disassembly, and assembly of various engine parts, including the rocker and fittings, tappets, oil sump, and timing gear.

Engine - Rocker and Fittings (Section 15-42)

The rocker assembly is an indirect valve actuating system comprising rocker arms and a shaft. Its primary function is to convert the radial movement from the camshaft lobe into linear movement at the poppet valve, thereby opening the valve. When the camshaft lobe raises the outside of the rocker arm, the inside presses down on the valve stem to open the valve. Conversely, when the outside of the rocker arm is allowed to return due to the camshaft's rotation, the inside rises, enabling the valve spring to close the valve.

Important Technical Specifications (Table 59. Rocker Levers, Rocker Shafts and Tappets Data):

• Valve Tip Clearances (measured cold):
  • SA, SB, SC: Inlet: 0.19-0.27mm, Exhaust: 0.56-0.64mm
  • SD, SF: Inlet: 0.35mm, 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

Lubrication System for Rocker and Fittings:

Oil is supplied from the main gallery through a drilling that extends through the crankcase and cylinder head to a small transfer gallery beneath the rocker shaft pedestal. An oversized rocker shaft fixing bolt hole allows oil to enter a drilling in the center of the rocker shaft. Further cross drillings distribute oil to each rocker pivot bush. A cross drilling within each rocker transfers oil to the top of the rocker, where it flows by gravity along a groove to the rocker tip.

Maintenance Features:

• Check (Condition): Regular inspection of the rocker shaft and rocker bushings for damage or excessive wear is crucial. Measurements of the rocker shaft diameter and rocker bearing bushes should be taken to confirm they are within service limits. Note that rocker bearing bushes are not renewable; if damaged or worn, the entire rocker assembly must be replaced. All oil-ways and cross drillings in the rocker shaft, rocker arms, and pedestals must be clear and free from debris, which can be achieved by blowing through them with an air line.
• Removal and Installation: Before removal, ensure the engine is cool and safe to work on. Disconnect fuel pipes from injectors and remove the rocker cover. The rocker shaft assembly, including pedestals, is lifted as a complete unit. Bridge pieces and push rods are then removed. For installation, ensure all components are clean and free from damage. Lubricate the rocker shaft and bearing bushes with clean engine oil. Ensure rockers and pedestals are in their original positions, paying attention to the oil feed pedestal and the longer bolt. Push rods must engage with camshaft tappets, and rockers must be located over bridge pieces. Tighten bolts to the specified torque values (Item 2 & 3: 24 Nm). After installation, measure and adjust valve clearances.
• Disassembly and Assembly: Disassembly involves lifting out rocker shaft fixing bolts and sliding pedestals, rockers, and wave washers off the rocker shaft. Label components to ensure correct reassembly. Check rocker shaft and bushings for wear. Assembly is the reverse of disassembly, with lubrication of the rocker shaft and bearing bushes with clean engine oil. Ensure correct positioning of rockers and pedestals, especially the oil feed pedestal. Insert fixing bolts to hold components loosely before fitting the assembly to the cylinder head.

Engine - Rocker Cover (Section 15-42-06)

Maintenance Features:

• Removal and Installation: Before removal, ensure the engine is cool and safe. Clean the top of the rocker cover and around the fuel injectors. Disconnect and remove fuel pipes from injectors, using blanking caps for open ends. Remove bolts and lift the rocker cover. Discard the old gasket and replace injector seals. For installation, clean all oil and sludge contamination from the rocker chamber. Install new injector seals and a new rocker cover gasket. Apply rubber lubricant to seals and install sleeves/covers over injectors before installing the rocker cover to prevent damage. Tighten bolts to the correct torque value (Item B: 24 Nm). After installation, connect fuel pipes and check for oil and fuel leaks.

Engine - Tappet (Section 15-42-21)

The engine must be inverted for tappet removal to prevent them and push rods from falling into the engine.

Special Tools:

• Crankshaft / Camshaft Timing Pin (444/448/672 Engine): Part No. 892/01148, Qty. 1

Maintenance Features:

• Before Removal: Drain engine oil. Disconnect fuel pipes and remove the rocker cover, fuel injection pump, rocker assembly, push rods, starter motor, oil sump, flywheel, and flywheel housing. Rotate the crankshaft to insert the camshaft timing pin through the gear into the aligning hole in the rear gear case. Remove the taper blanking plug and insert the crankshaft locking pin. Both camshaft and crankshaft locking pins must be in position before removing the camshaft assembly. Remove the fuel injection pump drive gear.
• Removal: Invert the engine. Remove the camshaft timing pin. Carefully withdraw the camshaft and gear assembly from the crankcase, supporting the camshaft to prevent lobes from contacting bearing surfaces. Access tappets through crankcase bedplate apertures and lift them out using a magnetic probe. Label tappets for original position replacement.
• Inspection: Inspect camshaft gear teeth, cam lobes, and cam bearing surfaces for damage, wear, scoring, or pitting. Check dimensions against service limits. Inspect tappet bearing surfaces and tappet bores in the crankcase for wear or damage. Ensure all oil ways in the cylinder block and camshaft are clear.
• Installation: Lubricate tappets and tappet bores with clean engine oil. Insert tappets into their original positions. Lubricate camshaft bearing journals. Carefully insert the camshaft assembly, aligning the timing hole in the camshaft gear with the dowel hole in the gear casing before meshing with the crankshaft gear. Insert the camshaft timing pin.
• After Installation: Torque tighten the fuel injection pump drive gear fixing nut. Reverse the "Before Removal" procedures.

Engine - Tappet Cover (Section 15-42-24)

Tappet covers are typically removed only when installing a new rocker cover or to measure and adjust valve clearances.

Maintenance Features:

• Remove and Install: Ensure the engine is cool and safe. Clean tappet covers and surrounding rocker cover areas. Remove tappet cover screws, ensuring they do not fall into the engine. Use a screwdriver in the slot to remove covers, taking care to prevent dirt or debris from entering the engine. For installation, inspect tappet cover seals for damage and replace if necessary. Install covers and tighten screws to the correct torque value (Item A: 9 Nm).

Engine - Oil Sump (Section 15-45)

Function Description:

The oil sump is a critical component of the engine's lubrication system. It stores engine oil, which is then distributed throughout the engine by the oil pump. The lubrication system uses galleries and drillings in the crankcase and cylinder head to lubricate and seal moving parts, reducing friction and wear. Oil also plays a vital role in cooling the engine by carrying heat away from components. A piston cooling jet sprays oil onto the underside of pistons for cooling. Oil is drawn from the sump via a suction strainer, which prevents large debris from damaging the pump. A relief valve limits maximum oil pressure by venting excess oil back to the inlet side of the pump. After passing through the oil cooler and filter, oil enters the main oil gallery, where an oil pressure switch monitors pressure. From the main gallery, oil is delivered to crankshaft main bearings, rocker assembly, camshaft, and timing gears. High-pressure oil, after passing through bearings, reverts to sump pressure and splash lubricates internal components like rocker tips, cam lobes, and timing gear teeth. Gravity drains oil from the cylinder head and crankcase back into the sump, and a drain slot allows oil from the timing case to return to the sump.

Special Tools:

• Template for Sealant Oil Sump - Pressed: Part No. 892/01149, Qty. 1
• Oil Sump Location Dowel: Part No. 892/01150, Qty. 2
• Template for Sealant Oil Sump (Cast): Part No. 892/12354, Qty. 1

Consumables:

• Clear Silicone Sealant: Part No. 4102/0901, Size 0.31L

Maintenance Features:

• Before Removal: Ensure the engine is cool and safe. Drain the engine oil.
• Removal: Remove fixing bolts and carefully lever the oil sump from the engine, as it may be adhered by sealing compound. Avoid excessive force to prevent damage. Retrieve the oil pick-up seal. Use a gasket removal compound to remove all traces of sealing compound from the oil sump and engine mating faces, ensuring no compound enters the engine. Thoroughly clean the oil sump with a degreasing agent.
• Installation: Lightly smear the new oil pick-up seal with oil and install it into the bedplate. Install two guide pins at the oil sump screw holes in the engine. Use the fixing bolts to locate the sealant template to the oil sump mating face, ensuring correct orientation. Apply a 4mm bead of clear silicone sealant around the oil sump flange, using the inside edge of the template as a guide, and around holes. Carefully remove the template without smudging the sealant beads. Apply another bead to join the sealant beads around holes with the bead around the oil sump flange. The oil sump must be installed and bolts torque tightened within 5 minutes of sealant application. Position the oil sump with the suction tube outlet aligned with the oil pump inlet port, taking care not to damage the oil pick-up seal. Locate the oil sump on the guide pins, avoiding smudging the sealant beads. Do not remove guide pins until sufficient bolts are installed. Install and tighten bolts to the correct torque value (Item 2: 24 Nm), noting that bolts are not installed at 6 positions.
• After Replacing: Allow sealant to cure for 20 minutes. Refill the engine with recommended engine oil. Start the engine and check for oil leaks.

Engine - Timing Gear (Section 15-51)

Function Description:

The timing gears are located inside a case at the flywheel end of the engine. They ensure that the camshaft operates the valves at the correct times relative to the crankshaft position. Valve timing is achieved by meshing the camshaft drive gear to the crankshaft gear at their correct angular positions.

Maintenance Features:

• General: The manual provides an introduction to the timing gear system, component identification, operation, and check (condition) procedures. It emphasizes the importance of correct valve timing for engine operation.

jcb 3DX Super Specifications