Installation Method for DAF 24V Starter

I. Pre-installation Preparation

Tools and Materials Preparation

• Special Tools: Torque wrench (50-300N·m), socket set (matched with starter fixing bolts), Phillips/flathead screwdriver, terminal crimping tool, insulating tape.

• Materials: 24V starter assembly (original equipment or OE-compliant aftermarket parts), new starter mounting gasket (if applicable), lock washers, high-temperature grease, battery terminal protector.

• Safety Supplies: Insulated gloves, safety goggles, anti-slip gloves.

Vehicle and Component Inspection

1. Park the vehicle on a flat surface, apply the parking brake firmly, turn off the engine, and disconnect the negative battery cable (to prevent short circuit during installation).

2. Check whether the model of the new starter matches the DAF vehicle model, and verify that the part number is consistent with the OE number.

3. Clean the starter mounting surface on the engine flywheel housing to remove oil stains, rust, and residues of the old gasket; inspect the tooth surface of the flywheel ring gear to ensure it is intact without missing teeth or excessive wear.

4. Inspect the starter solenoid switch terminals, carbon brushes, and drive gear to ensure they are not damaged.

II. Installation Steps

Positioning and Pre-installation

1. Lift the starter, align the drive gear end with the mounting holes on the flywheel housing, and match the starter's mounting bolt holes with the threaded holes on the flywheel housing.

2. Manually screw in 2-3 fixing bolts (do not tighten them completely), adjust the position of the starter, and ensure the meshing clearance between the drive gear and the flywheel ring gear meets the standard (usually 0.5-1.5mm, refer to DAF original parameters).

Tightening the Fixing Bolts

1. Use a torque wrench to tighten the fixing bolts in a cross-symmetrical sequence to the torque value strictly specified for the DAF model (the torque for most DAF 24V starter fixing bolts is 85-105N·m, refer to the maintenance manual of the corresponding model for exact values).

2. If a sealing gasket is installed on the mounting surface, ensure the gasket is not displaced or wrinkled to prevent oil leakage or water ingress.

Electrical Wiring Connection

1. Main Power Cable Connection: Connect the terminal of the thick positive battery cable to the main terminal (marked "+" or "B+") of the starter solenoid switch, put on a lock washer, and tighten the nut to a torque of 25-35N·m.

2. Control Wire Connection: Connect the terminal of the thin control wire from the ignition switch to the auxiliary terminal (marked "S" or "50") of the solenoid switch, and tighten the fixing nut to a torque of 8-12N·m.

3. Check all wiring terminals to ensure they are securely connected without looseness; wrap exposed wiring parts (if any) with insulating tape to prevent short circuit.

Reconnecting the Battery and Preliminary Testing

1. Reconnect the negative battery cable, apply battery terminal protector, and tighten the terminal nut.

2. Enter the cab, turn the ignition switch to the "ON" position, and check that no fault lights are illuminated on the instrument panel; then turn it to the "START" position and observe the starter operation:

• The drive gear should smoothly mesh with the flywheel ring gear, and the engine should start normally.

• There should be no abnormal noise (such as gear grinding or jamming sounds), and the drive gear should retract smoothly after the engine starts.

Precautions for Installation of DAF 24V Starter

I. Safety Precautions Before Installation

Power-off Operation Must Be Performed First

1. Prior to installation, be sure to disconnect the negative battery cable and wait for 5–10 minutes to ensure that the residual power in the vehicle's electrical system is completely discharged. This prevents short circuits that could burn out the starter solenoid switch or the vehicle's Electronic Control Unit (ECU).

2. It is forbidden to plug or unplug the starter wiring terminals while the battery is connected, to avoid electric arcs that may cause electric shock or fire hazards.

Component Compatibility Verification

1. Confirm that the OE part number of the new starter is fully compatible with the DAF vehicle model. The rated voltage of 24V must match the vehicle's electrical system; mixing 12V and 24V starters is strictly prohibited.

2. Check that the module and number of teeth of the starter drive gear match those of the flywheel ring gear. If the ring gear has missing teeth or excessive wear (tooth thickness wear ＞ 0.5mm), replace the ring gear before installing the starter.

Requirements for Mounting Surface Cleaning

1. Thoroughly clean the starter mounting surface on the flywheel housing to remove oil stains, rust, and residues of the old gasket. You can wipe the surface with a metal cleaner and wait for it to dry completely before installation.

2. If the mounting surface is uneven, repair it before assembly to prevent deformation of the starter housing.

II. Technical Precautions During Installation

Bolt Tightening Specifications

1. Tighten the fixing bolts in a cross-symmetrical sequence, and gradually tighten them to the standard torque in 2–3 steps (the torque for most DAF models is 85–105N·m). Never tighten the bolts on one side in a single step, as this may cause uneven stress and cracking of the starter housing.

2. The bolts must be equipped with lock washers. Do not use extended bolts or non-standard bolts to prevent thread slipping or insufficient installation depth.

Key Points for Adjusting Meshing Clearance

1. After pre-installation, check the meshing clearance between the drive gear and the flywheel ring gear. The standard value is 0.5–1.5mm (refer to the original DAF parameters for exact values).

2. Excessively small clearance will cause tight meshing of the gears, leading to jamming and abnormal noise during starting. Excessively large clearance will result in gear grinding. The clearance can be adjusted by changing the thickness of the starter mounting gasket.

Electrical Connection Specifications

1. The main power cable (thick cable) must be connected to the B+ terminal of the solenoid switch, and the control wire (thin wire) must be connected to the S terminal. Reversing the connections is strictly prohibited, as this will directly burn out the solenoid switch coil.

2. The tightening torque of the wiring terminals must meet the requirements: 25–35N·m for the main terminal and 8–12N·m for the auxiliary terminal. Loose connections will cause poor contact and overheating, while over-tightening will damage the terminal threads.

3. Apply conductive paste or anti-rust agent to all wiring terminals to prevent oxidation and rust. Wrap exposed metal parts with insulating tape.

4. References：
   

5. The following is the authority source tracing, including original factory technical documents, international and domestic industry standards, as detailed below:

7. I. Core Authority Sources

9. DAF Factory Service Manual

11. Publisher: DAF Trucks N.V.

12. Core Basis: The dedicated chapter on starter installation in the manual includes key parameters such as vehicle model compatibility, fixing bolt torque (85–105N·m), meshing clearance between drive gear and flywheel ring gear (0.5–1.5mm), definition of electrical terminals (B+ and S terminals), and their corresponding torque values (25–35N·m for the main terminal and 8–12N·m for the auxiliary terminal).

13. Obtaining Channels: Authorized DAF commercial vehicle dealers, the technical support section on the official website, or original factory electronic maintenance systems (e.g., DAF TechTool).

15. ISO 6143:2010 Road Vehicles - Starter Motors - Technical Requirements

17. Publisher: International Organization for Standardization (ISO)

18. Core Basis: It specifies the installation fit tolerances, electrical connection safety requirements, component compatibility criteria, and performance verification standards for starters, providing general technical specifications for installation operations.

19. Obtaining Channels: ISO official website, standard databases (e.g., BSI, SCC), or professional standard service platforms.

21. QC/T 731-2005 Technical Requirements for Automobile Starter Motors

23. Publisher: Ministry of Industry and Information Technology of the People's Republic of China (formerly the National Development and Reform Commission), under the jurisdiction of the National Technical Committee for Standardization of Automobiles, drafted by Changsha Automotive Electrical Research Institute, etc.

24. Issuance and Implementation Date: Issued on February 14, 2005, and implemented on July 1, 2005, replacing QC/T 29064-1992.

25. Core Basis: It supplements the reliability testing, fault judgment criteria, and component technical requirements after starter installation, which is applicable to domestic commercial vehicle maintenance specifications.

26. Obtaining Channels: National Public Service Platform for Standard Information, automotive industry standard databases (e.g., PlusStd).