The Starter for HOWO MAX 4X2 tractor is a high-torque 24V electric motor designed to crank the diesel engine reliably. This unit delivers 6.0 kW of power and ensures immediate ignition even in cold weather. When you need genuine HOWO Parts, this cranking motor is the perfect OE replacement. Below are detailed descriptions of every component included with this assembly.
The Starter 90P55 24V is the main unit of this kit. This device features a planetary gear reduction that multiplies torque while keeping the motor compact. The cranking motor produces a lock torque above 180 Nm and draws up to 900 A under load. The housing is sealed to IP54 standard. The solenoid pushes the pinion gear into the flywheel before contacts close. This component has passed 30,000 cycle testing. Every motor is 100% factory tested.
Three hexagon flange bolts secure the cranking motor to the engine block. These bolts are engineered specifically for the mounting flange. The 10.9 grade prevents loosening under vibration. These bolts must be torqued to 80 Nm when installing the unit. Reusing old bolts is not advised. The kit includes fresh bolts. Apply thread locker before installing the device.
This galvanized A2 washer is used on the main power terminal. The washer provides excellent corrosion resistance for the electrical connection. When connecting the battery cable, place this washer between the cable lug and the nut. The washer maintains a low-resistance connection. A loose connection can cause voltage drop. Always replace the washer when servicing the motor.
The M10 A2-70 screw nut secures the battery cable to the main terminal. When installing the unit, tighten this nut to 25 Nm. Overtightening can strip the terminal stud, while undertightening causes a high-resistance connection. The terminal nut should be checked during every preventive maintenance interval. If the engine cranks slowly, inspect this nut for looseness on the device.
The terminal hood is a rubber boot that covers the main power terminal and solenoid trigger terminal. This hood protects the terminals from water, road salt, and debris. Without this hood, moisture can enter the solenoid contacts, causing intermittent starting. When replacing the motor, always transfer the original hood or install the new one. The hood is made from EPDM rubber.
The corrugated pipe clamp secures the solenoid trigger wire to the engine harness. This clamp prevents the trigger wire from chafing against engine components. When routing the wiring, use this clamp to keep the harness away from exhaust manifolds. A missing harness clamp can allow the trigger wire to contact hot surfaces. This clamp ensures that the trigger wire does not interfere with removal.
This unit produces lock torque above 180 Nm and cranking torque exceeding 80 Nm, turning over large diesel engines instantly. The motor delivers 6.0 kW at 24V. The planetary gear reduction multiplies torque without increasing current draw. This device ensures reliable starts even in cold weather.
The motor housing is epoxy-coated steel, and all fasteners are zinc-plated or stainless steel. The sealed drive housing (IP54) keeps out dust and moisture. The terminal hood protects electrical connections. This component withstands harsh African road conditions.
The solenoid engages the pinion gear with the flywheel before contacts close, eliminating grinding. This design extends the life of both the motor and the ring gear. The solenoid contacts are silver-alloy for long switching life. This unit is engineered for durability.
This cranking motor comes with all necessary mounting hardware: three flange bolts, one terminal washer, one M10 nut, the terminal hood, and a corrugated pipe clamp. No extra purchases are needed to install this unit. The kit also includes factory-tested documentation and torque specifications for proper installation.
The Starter for HOWO MAX 4X2 is a series-wound, four-brush design with a planetary gear reduction system. The armature is dynamically balanced, and the commutator is precision-undercut for long brush life. The device draws less than 100 A at no load and up to 900 A under locked rotor conditions. The no-load speed exceeds 3500 rpm. The operating voltage range is 18 V to 28 V. The pinion has 11 teeth and rotates clockwise. The mounting flange conforms to SAE J542 standard. The overall weight is approximately 12.5 kg.
This unit is compatible with SINOTRUK MC11, MC13, and MT13 engines. It has been tested to 30,000 cranking cycles without performance degradation. The motor passed 240 hours of salt spray testing and vibration testing at 5g acceleration. It can withstand thermal shock from -40°C to +120°C. The design life exceeds 200,000 starts under normal operating conditions. This component is the same unit supplied on new HOWO MAX 4X2 tractors from the factory.
The solenoid is a sealed, epoxy-encapsulated unit that prevents coil failure. The solenoid pull-in winding draws approximately 40 A initially, then the hold-in winding consumes only 5 A once the motor is cranking. This solenoid design reduces battery drain. The device also includes an overrunning clutch that protects the motor from being over-spun by the engine after start.
The brushes are made from copper-graphite compound. The brush holder assembly allows brush replacement during overhaul. However, genuine unit replacement is recommended over repair. The motor is marked with the batch number on the housing label. Always verify the part number matches the original before installation of the component.
Before installing the Starter, disconnect both negative battery cables. Clean the mounting surface on the engine block. Position the unit against the engine block, ensuring the pinion is free. Install the three M12x35 flange bolts but do not fully tighten them yet.
Torque the bolts to 80 Nm in a diagonal sequence. Do not reuse old bolts. The motor must be seated flat against the engine block. Connect the main battery cable to the M10 terminal using the included A2 washer and nut. Tighten the nut to 25 Nm. Connect the solenoid trigger wire to the smaller terminal.
Install the terminal hood over both connections. Use the corrugated pipe clamp to secure the trigger wire harness away from heat sources. Reconnect the battery cables and test the unit by starting the engine. Listen for unusual noises, which indicate pinion clearance issues.
If the cranking motor does not run, check the battery voltage under load. Measure voltage drop across the main cable; it should be less than 0.5 V. Verify that the solenoid trigger wire receives 24 V when the key is turned to START.
If all electrical checks pass but the unit still does not operate, perform a bench test: remove the motor, clamp it in a vise, and connect jumper cables directly from a known good battery. The pinion should extend and spin forcefully. If the device fails the bench test, it is defective and should be replaced.
After successful installation, program the engine ECU to clear any stored starting system faults. Some HOWO MAX models require a teach-in procedure for the immobilizer system after replacement.
The unit does not require any break-in period. Record the replacement in the vehicle maintenance log. A correctly installed component will provide years of trouble-free service.
Common installation mistakes include failing to disconnect batteries, using the wrong bolts, overtightening the main terminal nut, forgetting the terminal hood, and not torquing mounting bolts properly. Avoid these errors to ensure longevity. If the engine cranks slowly after installation, suspect a weak battery or corroded cable ends, not a defective unit. A genuine component is a precision part; treat it with care.
If the unit produces a rapid clicking sound, the cause is usually low battery voltage or a poor connection. Check the battery charge and clean the main cable terminals. A single loud click without cranking indicates a stuck solenoid or seized motor. Tap the body lightly while attempting to start; if the engine cranks, the solenoid contacts are worn.
If the motor runs but does not engage the flywheel, the pinion gear has failed. Replace the component immediately. If the unit continues to run after the engine starts, the solenoid contacts have welded closed. Disconnect the battery immediately. A grinding noise during cranking suggests incorrect pinion clearance or damaged flywheel teeth.
The device may draw excessive current if the engine is seized or if there is an internal short. Measure current draw with a DC clamp meter; a locked rotor should draw below 1000 A. Intermittent operation is often caused by a failing solenoid or loose connections.
Inspect the trigger wire circuit. Voltage drop testing can pinpoint high-resistance connections. A slow-cranking motor in warm weather usually indicates worn brushes or a failing battery. Perform a load test on the battery first. If the battery passes, replace the unit.
The cranking motor may be contaminated by oil leaks from the engine. Oil inside the motor can cause brush sticking. Repair the oil leak before replacing the device. Water ingress is another common killer. A unit with rust inside is not repairable. Install the terminal hood and ensure the component is not mounted where it can be submerged. Always keep the motor clean and dry for maximum life.
The Starter requires minimal routine maintenance. Every 50,000 km, inspect the main cable connection for looseness or corrosion. Check the terminal hood for cracks. Ensure the mounting bolts remain tight; a loose unit can cause pinion misalignment. Listen for unusual noises during cold starts; a high-pitched whine indicates that the pinion is not fully engaging.
Look for oil leaks near the area. Keep the exterior clean using a dry rag; never pressure wash directly at the motor. If the unit cranks slower than normal but the battery is healthy, have it tested. Replace the component preemptively after 500,000 km or 10,000 operating hours.
The solenoid can be tested without removing the unit. Connect a voltmeter between the solenoid trigger terminal and ground. When the key is turned to START, the voltmeter should show full battery voltage. The main cable voltage drop test is performed by measuring between the battery positive post and the main terminal while cranking.
A drop exceeding 0.5 V indicates a corroded cable. The ground path can be tested by measuring voltage between the housing and battery negative post while cranking; the drop should not exceed 0.2 V.
When storing a vehicle, disconnect the battery. Repeated attempts to start with a depleted battery subject the motor to low-voltage burnout. Avoid cranking for more than 30 seconds continuously, followed by a 2-minute cooling period. If the engine does not start after three cranking attempts, diagnose the fuel system rather than continuing to crank the device. Following these maintenance guidelines will maximize life and performance.
Q: Does this Starter fit all HOWO MAX 4X2 models? Yes, this unit fits all HOWO MAX 4X2 tractors equipped with MC11, MC13, or WD615 diesel engines. Check the original part number before ordering; it should be 201V26201-7199. This is a direct OE replacement.
Q: What is the warranty period for this Starter? The Starter carries a 12-month warranty against manufacturing defects. The warranty does not cover damage caused by low battery voltage, improper installation, or contamination. Always have the unit installed by a qualified technician.
Q: Can the Starter be repaired if it fails? Some components such as the brushes and solenoid can be replaced, but genuine unit replacement is recommended for reliability. A rebuilt motor may have unknown history; a new component ensures full performance.
Q: Why does the Starter smell burnt after cranking? A burnt smell indicates overheating. This often results from cranking too long or attempting to start with a weak battery. Low voltage causes excessive current draw. Replace the unit and check the battery condition.
Q: How many starts can I expect from this Starter? With proper maintenance, this device is designed for over 200,000 start cycles. Actual life depends on battery condition and cranking duration. In typical line-haul service, the unit lasts 5 to 8 years. Replace it preemptively at major engine overhauls.
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