Clutch plate 8973771490 8-97377149-0 8973203550 is suitable for Isuzu 4KH1 4HF1 4HG1

Pre-installation Preparation

• Vehicle Fixation and Protection: Park the vehicle on a flat surface, engage the handbrake, and secure the wheels with wheel chocks. Disconnect the negative terminal of the storage battery to prevent short circuits. Lift the vehicle with a jack and support it stably with safety stands—never rely solely on the jack for operation. Finally, remove the engine splash shield to facilitate subsequent operations on transmission components.

• Tool and Accessory Preparation: Prepare socket wrenches, a torque wrench, a clutch kit (including friction plate, pressure plate, release bearing), lithium-based grease, cleaning cloths, and a clutch alignment tool. Confirm that the new friction plate is compatible with the corresponding Isuzu model, and check that the friction plate is free of cracks, oil contamination, and spline wear.

Removing Components to Expose the Clutch Assembly

Component Cleaning and Inspection

Core Installation Operations

• Positioning the Friction Plate: The friction plates of some Isuzu models are equipped with bosses or markings. Pay attention to the installation direction—usually, the side with the boss faces the transmission, and the side without the boss faces the flywheel. Insert a dedicated alignment tool or the transmission input shaft into the splined hole of the friction plate to ensure concentricity with the flywheel, preparing for the smooth installation of the input shaft later. Meanwhile, apply a small amount of grease evenly inside the splined hole of the friction plate and wipe off excess grease after application to avoid contaminating the friction surface.

• Installing and Securing the Pressure Plate: Align the pressure plate with the locating pins on the flywheel and place it over the friction plate. Initially tighten the pressure plate mounting bolts by hand, then use a torque wrench to tighten them step by step in a crisscross sequence. For most Isuzu models, the pressure plate bolts are recommended to be tightened to the specified torque (25–30Nm for commercial vehicles; refer to the vehicle service manual for exact values) to prevent pressure plate deformation due to uneven force.

• Assembling Release Components: Install the release bearing and release fork assembly, ensuring the release bearing rotates smoothly without jamming. Apply an appropriate amount of lithium-based grease to the contact area between the release fork and release bearing to reduce wear, taking care not to over-apply to avoid grease overflow contaminating the friction plate. Ensure the rubber dust cover is properly installed to prevent dust from entering and affecting component lifespan.

Reassembly and Commissioning

• Transmission Reset: Use a lifting tool to slowly lift the transmission, align it with the engine interface, and ensure the input shaft is smoothly inserted into the splined hole of the friction plate—do not force it to avoid damaging the splines and friction plate. Subsequently, tighten the transmission mounting bolts to the specified torque and reconnect components such as the clutch oil lines and shift cables. For hydraulic clutches, replenish hydraulic fluid and completely bleed air from the system to prevent poor clutch disengagement.

• Inspection and Adjustment: Reconnect the negative terminal of the storage battery and adjust the clutch pedal free travel—Isuzu models generally require an adjustment range of 10–25mm, which is calibrated via the adjustment screw on the pedal. After starting the vehicle, press the clutch pedal repeatedly to test the smoothness of clutch engagement and disengagement, as well as normal gear shifting. If issues such as slipping or incomplete disengagement occur, promptly inspect and adjust parts such as the friction plate direction, bolt torque, or hydraulic system.

Parts and Pre - installation Preparation

1. Ensure Part Compatibility

   Select genuine clutch friction plates that match the specific model and year of the Isuzu vehicle. Before installation, inspect the friction plate for cracks, spline wear and other defects. Meanwhile, check the fit between the splines of the driven plate hub and those on the transmission input shaft to ensure they can move freely without jamming or excessive looseness.

2. Secure the Vehicle Properly

   Park the vehicle on a flat surface, fully engage the parking brake and secure the wheels with wheel chocks. After lifting the vehicle with a jack, it must be firmly supported by safety stands. Never rely solely on the jack, as this could lead to dangerous vehicle movement during operation. Additionally, disconnect the negative terminal of the battery to prevent short circuits and ensure operational safety.

3. Calibrate Tools in Advance

   Prepare necessary tools such as a socket wrench, torque wrench, and special guide shaft. In particular, the torque wrench should be calibrated beforehand to avoid component damage caused by torque deviations. The special guide shaft must match the spline size of the Isuzu model to ensure accurate installation and positioning.

Standardized Installation Operations

1. Adhere to Installation Orientation

   If the friction plate is equipped with a boss or marked with indicators like "Flywheel Side", strictly follow these marks during installation. Typically, the side with the boss faces the transmission, and the side with the damper plate faces the pressure plate. Reversing the installation will result in incomplete clutch disengagement and rough gear shifting. Insert a special guide shaft or the transmission input shaft into the spline hole of the friction plate to guarantee concentricity between the friction plate and the flywheel.

2. Maintain Cleanliness of Components

   Before installation, thoroughly clean oil stains, metal debris and rust from the surfaces of the flywheel and pressure plate using a cleaning cloth. Keep the friction plate clean at all times and strictly prevent oil contamination. Keep hands dry during operation. If hands accidentally get contaminated with oil, clean them thoroughly with a special cleaning agent; otherwise, clutch slipping may occur.

3. 
   

4. References：
   

5. There is no unified and fixed source for the previously mentioned content regarding the installation of clutch friction plates for Mitsubishi vehicles. As for the precautions for installing clutch friction plates in Isuzu vehicles, the relevant information is mostly derived from summaries of general maintenance knowledge on professional automotive repair platforms and shared maintenance experience specifically for this brand's models. The specific reference sources are as follows:
7. Autohome

   This platform features specialized Q&A and popular science content focusing on the assembly and adjustment of automotive clutches. It includes maintenance data for the SBR and JBR series clutches of Isuzu, covering specification requirements for components such as clutch discs and springs, as well as key parameters like the clearance between the pedal shaft and bushings. Additionally, the general precautions for installing clutch friction plates shared on the platform—such as keeping the friction plates clean, paying attention to the installation direction, and standardizing lubrication—are also applicable to most fuel-powered Isuzu models.
8. PCauto

   The platform has published numerous articles related to clutch assembly, and many of the core key points covered are suitable for Isuzu models. For example, it emphasizes the use of a dedicated guide shaft during installation to ensure the concentricity of the driven plate and the flywheel, the need to alternately tighten the pressure plate bolts in a diagonal pattern, and the requirement to control the free travel of the clutch pedal. It also mentions detailed points such as installing the springs of multi-coil spring clutches in groups based on their free lengths. All these details provide valuable reference for the installation of Isuzu clutch friction plates.
9. Bitauto Encyclopedia

   The summarized steps and precautions for replacing automotive clutch discs on this platform, including general rules such as aligning marks when installing new clutch discs and clarifying the orientation of the guide flange, can also serve as a reference basis for the installation operations of Isuzu's automotive clutch friction plates.