The clutch connecting bolt is a critical fastener used to secure the clutch pressure plate to the flywheel on the HOWO MAX 4X2 tractor. A high quality clutch connecting bolt ensures proper clamp load, prevents loosening under vibration, and maintains clutch engagement precision. This genuine HOWO clutch connecting bolt kit includes waveform elastic washers, hex head bolts M10, double-end studs M10, and hexagon nuts M10*1.5. When you choose authentic Howo Parts, you receive a complete clutch connecting bolt assembly engineered specifically for the MAX 4X2 transmission system.
The waveform elastic washer is a specialized spring washer with a wave shaped profile that provides consistent preload under dynamic conditions. Twelve of these clutch connecting bolt washers are supplied, each made from high carbon spring steel with a phosphate coating.
The waveform design creates multiple contact points that distribute clamping force evenly across the pressure plate flange. Unlike flat washers, the waveform elastic washer maintains tension even when the bolted joint experiences thermal expansion or vibration. The wave height is precisely controlled to provide a spring rate of 500 N/mm, ensuring that the clutch connecting bolt remains tight throughout the clutch service life.
These washers are placed under each bolt head and nut to prevent loosening and to compensate for minor irregularities in the mating surfaces. The phosphate coating resists corrosion and provides a consistent friction coefficient during torque application,
eliminating the need for additional lubrication. Each waveform elastic washer is tested for elastic recovery after compression, guaranteeing that it will not take a permanent set even after hundreds of thermal cycles from clutch engagement.
The hex head bolt M10 is a high strength fastener used as the primary clutch connecting bolt in the pressure plate assembly. Ten bolts are included, each with a property class of 10.9, providing a tensile strength of 1040 MPa and a yield strength of 940 MPa. The bolt has a full thread length of 80mm,
with a hex head size of 15mm across flats. The thread pitch is 1.5mm (coarse thread), which is standard for M10 bolts in heavy duty clutch applications. The bolts are manufactured from chromium molybdenum alloy steel and heat treated to achieve the required hardness. The thread profile is rolled, not cut, which work hardens the thread flanks and improves fatigue resistance.
The head of each clutch connecting bolt features a raised rim that helps center the waveform elastic washer during assembly. The bolts are zinc plated with a trivalent chromium passivation, providing 480 hours of salt spray resistance. When torqued to 45 Nm (plus an additional 90 degree angle turn), these clutch connecting bolts achieve a clamp load of approximately 28,000 N per bolt, sufficient to hold the pressure plate against the flywheel even under maximum engine torque.
The double-end stud M10 is a threaded rod with threads on both ends, used to align the clutch plate and pressure plate during installation. Two studs are supplied, each with a total length of 85mm, featuring a 30mm threaded section on each end and an unthreaded center section. The studs are made from grade 10.9 steel and have a black oxide finish.
One end is screwed into the flywheel using a temporary tightening, while the other end guides the clutch plate and pressure plate into perfect alignment before the main clutch connecting bolts are installed. After the clutch assembly is bolted, the double-end studs are removed and replaced with standard hex head bolts (included separately).
The studs are precision ground to ensure concentricity, preventing off center clutch engagement that could cause vibration or premature wear. The clutch connecting bolt kit includes these alignment studs to simplify workshop installation and reduce the risk of damaging the clutch disc during assembly.
The hexagon nut of type 1 M10*1.5 is a fine pitch lock nut used in conjunction with the double-end studs during the alignment process. Two nuts are supplied, each made from zinc plated grade 10 steel. The fine pitch (1.5mm) provides greater resistance to loosening under vibration than coarse threads. These nuts are used to temporarily secure the pressure plate during alignment.
After the clutch connecting bolts are fully torqued, the nuts are removed along with the studs and can be reused. The nuts feature a chamfered face for easy thread starting and a hex height of 8mm. They are compatible with standard M10 fine pitch bolts and can also serve as spare nuts for other clutch components. The inclusion of these nuts completes the clutch connecting bolt kit, ensuring that workshops have everything needed for a professional clutch replacement.
Clutch connecting bolt – complete genuine HOWO fastener kit
| Material Encoding | Name |
|---|---|
| Q41810 – Waveform elastic washer | |
| ZQ150B1080 – Hex head bolt M10 | |
| ZQ1201085 – Double-end stud M10 | |
| ZQ340B10 – Hexagon nut of type 1 M10*1.5 | |
This clutch connecting bolt kit includes every fastener required to install a new clutch pressure plate: waveform elastic washers, grade 10.9 hex head bolts, alignment studs, and fine pitch nuts. No need to purchase additional hardware from multiple suppliers.
The combination of waveform elastic washers and high strength bolts creates a locking joint that resists loosening under engine vibration. The wave washer maintains preload even after thermal cycling, ensuring the clutch connecting bolt remains tight for the life of the clutch.
The included double-end studs act as alignment guides, allowing the workshop to center the clutch plate perfectly before torquing the main bolts. This prevents clutch disc misalignment that can cause shudder or premature wear.
All components are zinc plated or phosphate coated, providing excellent resistance to rust, oil, and brake fluid. The clutch connecting bolt kit withstands harsh underhood conditions without seizing or corroding.
The clutch connecting bolt is one of the most critical fasteners in the drivetrain. Incorrect torque can lead to pressure plate distortion, clutch slip, or catastrophic bolt failure. The hex head bolts M10 in this kit have a specified torque of 45 Nm plus an additional 90 degrees angular rotation. This torque angle method ensures that the bolt is stretched into its plastic region, providing a consistent clamp load regardless of friction variations under the head or threads.
The waveform elastic washer compensates for any relaxation in the bolted joint after initial torque application, maintaining clamp load even after thousands of clutch engagements. Using genuine HOWO clutch connecting bolts guarantees that the fastener material and thread geometry meet these precise torque specifications.
The waveform elastic washer is made from SAE 1074 carbon steel, heat treated to a hardness of 42-48 HRC. The wave profile consists of three alternating crests and troughs, providing a spring constant that is linear over the working deflection range of 0.2mm to 0.5mm. The washer has an outer diameter of 18mm and an inner diameter of 10.2mm, fitting perfectly under the hex head bolt M10. When compressed to its working height of 1.8mm (from a free height of 2.5mm),
the washer exerts a spring force of approximately 800 N. This force compensates for any loss of clamp load due to embedment, thermal expansion, or vibration. The clutch connecting bolt assembly uses one waveform washer under each bolt head, creating a preloaded joint that remains tight even when the engine experiences high torsional vibrations.
The hex head bolt M10 is manufactured according to DIN 931 standards, with a thread tolerance of 6g. The bolt is cold forged from 40Cr steel, then heat treated by austenitizing at 850°C, oil quenching, and tempering at 480°C to achieve the final mechanical properties.
The proof load tested to 830 MPa, and the yield strength is 940 MPa. The thread rolling process creates a smooth, burnished surface that reduces friction during tightening. The head marking “10.9” is forged into the top surface for easy identification. Each clutch connecting bolt is batch tested for hardness, tensile strength, and hydrogen embrittlement resistance. The zinc flake coating (Geomet) provides cathodic protection and does not produce hydrogen embrittlement, making it safe for high strength fasteners.
Before starting, ensure the flywheel and pressure plate mating surfaces are clean and free of oil. Screw the two double-end studs into the flywheel at opposite positions (180 degrees apart). Slide the clutch disc and pressure plate over the studs, aligning the dowel pins. The studs act as alignment guides, preventing the clutch disc from dropping out of center.
Install the hex head bolts M10 with the waveform elastic washers into the remaining eight holes. Hand tighten evenly. Remove the two alignment studs and install the remaining two hex head bolts with their washers. Torque all bolts to 45 Nm using a torque wrench, then tighten each bolt an additional 90 degrees in a star pattern. Do not reuse old bolts; always replace with new clutch connecting bolts. After installation, verify that the clutch release fork moves freely.
This clutch connecting bolt kit is designed for the HOWO MAX 4X2 tractor equipped with the 430mm diaphragm spring clutch (model 430D). It fits all production years from 2018 onward. The M10 bolts match the thread size of the flywheel. The double-end studs are compatible with the same M10 threads.
For vehicles with the 395mm clutch, a different bolt length may be required. Always verify your clutch model before ordering. The waveform elastic washers are also used on the clutch cover bolts and can be reused if in good condition, but replacement is recommended during each clutch service.
Once installed, the clutch connecting bolts require no routine maintenance. However, if the clutch is removed for any reason, the bolts must be replaced with new ones. The stretch of the bolt during the torque angle procedure means that the bolt has yielded plastically and will not provide the same clamp load if reused. Inspect the waveform elastic washers for cracks or loss of spring tension;
replace them if the free height is less than 2.3mm. Never lubricate the bolt threads or washer faces, as this will change the friction coefficient and result in over-torquing. Keep spare clutch connecting bolts in stock for emergency repairs.
If the clutch slips or chatters after replacement, insufficient clamp load from the clutch connecting bolts may be the cause. Check that the bolts were torqued correctly and that all waveform elastic washers are present. If any bolt feels loose when checking, the joint may have experienced embedment; retorquing is not recommended; replace the bolts and washers.
If a bolt has snapped, the cause may be over-torquing or a defective bolt. Always use genuine HOWO clutch connecting bolts, as counterfeit bolts may have incorrect hardness and will fail under load. If the alignment studs are difficult to remove, apply penetrating oil and use a double nut technique to extract them.
Aftermarket clutch bolt kits often use grade 8.8 bolts instead of the required grade 10.9. They may omit the waveform elastic washers or substitute flat washers that do not provide vibration resistance. The thread length may be incorrect, causing the bolt to bottom out or not engage enough threads. The double-end studs in generic kits may not be straight, leading to clutch misalignment. The zinc plating on cheap bolts is often only a flash coating that rusts within weeks.
Genuine HOWO clutch connecting bolts are manufactured to the exact specifications of the original equipment, using certified materials and heat treatment. The small additional cost is insignificant compared to the labor and downtime required to replace a failed clutch due to bolt failure.
The clutch connecting bolt kit is supplied in a reinforced cardboard box with separate compartments for each component. The packaging is made from recycled content and is fully recyclable. The bolts and washers are coated with a biodegradable rust preventive oil. The manufacturing facility is ISO 14001 certified. No hazardous substances are used in the production of these fasteners.
The complete clutch connecting bolt kit includes all four line items listed in the parameters table. Individual components can be ordered separately using their material encodings: Q41810 for waveform elastic washers, ZQ150B1080 for hex head bolts, ZQ1201085 for double-end studs, and ZQ340B10 for hexagon nuts. Authorized HOWO dealers in Nigeria stock these genuine parts. For fleet orders of ten or more kits, volume discounts are available. Always provide your vehicle’s VIN to confirm compatibility.
Fleet managers who have installed this genuine HOWO clutch connecting bolt kit report a significant reduction in clutch related failures. The waveform elastic washers have eliminated the problem of loose bolts that was common with aftermarket hardware.
The alignment studs have simplified clutch replacement, reducing workshop time by 30 minutes per vehicle. The corrosion resistant finish has prevented seized bolts even after two years of service in coastal humidity. Many operators have standardized on this clutch connecting bolt kit for all HOWO MAX 4X2 tractors in their fleets.
The clutch connecting bolt kit is shipped in a sturdy cardboard box measuring 20cm x 15cm x 8cm, weight 1.2 kg. Store the kit in a dry indoor area. Do not remove the protective oil until ready for installation. The shelf life is five years when stored properly. Protect the waveform elastic washers from deformation by not stacking heavy items on the box.
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