Product Profile
The COGENG 240067A1 is an inductive magnetic pickup sensor engineered as a direct replacement for Case skid steer and compact track loader applications. This component detects the rotational speed of the engine flywheel or ring gear and converts that mechanical motion into an alternating current (AC) electrical pulse signal. The signal is transmitted to the engine control unit and the operator's instrument panel, providing real-time engine RPM data for fuel management, machine diagnostics, and the tachometer display.
COGENG Part Number: 240067A1
OEM Reference: Case 240067A1
Sensor Classification: Passive inductive speed sensor (magnetic pickup / MPU)
Power Requirement: None — generates its own AC voltage signal from gear tooth movement
Output Characteristic: Sine wave signal with amplitude and frequency increasing proportionally to engine speed
Physical Build: Threaded cylindrical metal body with hex drive collar, integrated weatherproof 2-pin connector, and sealed magnetic sensing tip
| Parameter | Specification |
|---|---|
| Product Name | Revolution Speed Sensor (Engine Speed Sensor) |
| COGENG Part Number | 240067A1 |
| OEM Equivalent | Case 240067A1 |
| Product Type | Magnetic Pickup / Inductive Speed Sensor |
| Sensor Type | Variable reluctance (magnetic) |
| Output Signal | AC voltage (frequency proportional to engine speed) |
| Application | Engine RPM monitoring / Crankshaft position |
| Compatible Models | Case 905B, 906B Excavators |
| Material | Iron + Rubber (seals: NBR) |
| Packing | PP bag inside, carton box outside |
| Place of Origin | Guangdong, China |
| Brand Name | COGENG |
| Certification | ISO9001 |
| Supply Capacity | 500 PCS |
| Brand | Part Number |
|---|---|
| COGENG | 240067A1 |
| Case | 240067A1 |
| Interchange | 240067A2, 240067A3, 240067A4, 87017010, 87017011 |
| Parameter | Specification |
|---|---|
| Model | Case 905B Excavator |
| Type | 9-ton Crawler Excavator |
| Series | B-Series |
| Engine | Case / Cummins diesel |
| Operating Weight | 8,500 - 9,500 kg |
| Parameter | Specification |
|---|---|
| Model | Case 906B Excavator |
| Type | 9-ton Crawler Excavator |
| Series | B-Series |
| Engine | Case / Cummins diesel |
| Operating Weight | 9,000 - 10,000 kg |
| Engine Model | Displacement | Cylinders | Found In |
|---|---|---|---|
| Case/Cummins 4-cylinder | 3.9L - 4.5L | 4-cylinder | 905B, 906B |
| Case/Cummins diesel | Various | 4-cylinder | 905B, 906B |
Note: Verify compatibility with your equipment model, engine serial number, and production year before ordering. Contact COGENG with your machine details for exact application verification.
| Component | Function |
|---|---|
| Sensor Type | Variable reluctance (magnetic pickup) |
| Target | Flywheel ring gear teeth or crankshaft tone wheel |
| Output | AC voltage sine wave (frequency = engine RPM × number of teeth) |
| ECU Use | Engine speed calculation, fuel injection timing, protection |
| Engine Speed (RPM) | Output Voltage (AC) | Frequency (Hz) |
|---|---|---|
| Cranking (200 RPM) | 0.5 - 1.5 V | Low frequency |
| Idle (800 RPM) | 2.0 - 4.0 V | Medium frequency |
| Working (1,500 RPM) | 4.0 - 8.0 V | Higher frequency |
| Rated (2,200 RPM) | 6.0 - 12.0 V | High frequency |
| Function | Description |
|---|---|
| Engine RPM Display | Provides signal to tachometer (dash display) |
| Fuel Injection Timing | ECU uses speed signal for timing calculation |
| Engine Protection | Over-speed detection and derate |
| Starting Control | Starting motor disengagement signal |
| Diagnostics | Speed sensor fault detection (DTC) |
| Parameter | Specification |
|---|---|
| Sensor Type | Variable reluctance (magnetic pickup) |
| Output Signal | AC voltage (sine wave) |
| Output Voltage (min) | 1.0 V AC @ 200 RPM |
| Output Voltage (typical) | 2-12 V AC (engine speed dependent) |
| Coil Resistance | 200 - 500 Ω @ 20°C |
| Inductance | 100 - 300 mH |
| Air Gap | 0.5 - 1.5 mm (0.020 - 0.060 in) |
| Connector Type | 2-pin Deutsch / AMP |
Compatible Equipment
The 240067A1 speed sensor is specified for Case compact equipment, particularly models in the 905B and 906B series. These are compact wheel loaders where accurate engine speed sensing is critical for both engine management and operator feedback. Confirmed applications include:
Case 905B – Compact wheel loader
Case 906B – Compact wheel loader
This sensor may also cross-reference to other Case models and potentially certain New Holland compact equipment sharing the same engine platform and sensor specification. Always confirm the OEM part number printed on your original sensor body or listed in your machine's illustrated parts catalog before purchasing.
Installation Instructions
The air gap between the sensor tip and the flywheel gear teeth is the single most important factor for correct operation. Perform this installation with the engine fully stopped, the ignition key removed, and the battery disconnected.
Step 1 – Locate the Sensor Port
On Case 905B and 906B engines, the speed sensor is typically threaded into the flywheel housing or bell housing, positioned so the sensor tip faces the ring gear teeth at a perpendicular angle. Consult your machine's service manual for the exact location if not immediately visible.
Step 2 – Remove the Original Sensor
Trace the sensor wire to its electrical connector and disconnect it by pressing the release tab. Do not pull on the wiring itself. Loosen the lock nut, then unscrew the sensor completely from its threaded bore. Note the depth or count the exposed threads if possible — this provides a reference for the new sensor installation.
Step 3 – Inspect and Clean
Look inside the sensor port with a flashlight if the gear teeth are visible. Confirm the teeth are intact and free of excessive wear or metal debris. Clean the threaded bore and the sealing surface with a lint-free rag to remove oil, dirt, and any metallic particles that could affect sensor seating.
Step 4 – Install and Gap the New Sensor
Hand-thread the COGENG 240067A1 sensor into the bore until the sensing tip makes light contact with a ring gear tooth. This is your zero-reference point. From this position, rotate the sensor counterclockwise (back out) exactly ½ to ¾ of a full turn. This creates the correct air gap — typically 0.5 mm to 0.8 mm — for a strong and clean RPM signal on this engine.
Step 5 – Lock Position and Connect
While holding the sensor body steady to preserve the set air gap, tighten the lock nut firmly against the mounting surface. Use a backup wrench on the sensor hex if available. Reconnect the wiring harness plug, ensuring the connector latches securely and the weather seal is fully seated to prevent moisture entry.
Step 6 – Verify Operation
Reconnect the battery. Start the engine and observe the tachometer or instrument panel display. The RPM reading should be steady and responsive without jumping, flickering, or dropping to zero. If the reading is erratic or absent, switch off and recheck the air gap setting and connector engagement.
Safety Guidelines
Engine Isolation: Always disconnect the battery and ensure the ignition is off before working on any engine sensor. This prevents accidental engine cranking and protects the electrical system from short circuits.
Burn Hazard: Engine block, exhaust, and flywheel housing surfaces become extremely hot during operation. Allow the engine to cool thoroughly before reaching into the engine compartment.
Rotating Component Danger: Keep hands, fingers, and tools well away from any opening that provides access to the flywheel or ring gear while the engine is running or being cranked.
Magnetic Field Advisory: The sensor tip contains a powerful permanent magnet. Maintain a safe distance from pacemakers, implantable defibrillators, and other sensitive medical devices. Keep the sensor away from credit cards and electronic storage media.
Connector Environment: The sensor connector must be fully sealed against the elements. A loose or improperly seated connector allows water, mud, and dust to enter, causing signal degradation and terminal corrosion.
Frequently Asked Questions
Q: The tachometer does not work after I installed the new sensor. What did I do wrong?
A: In nearly every case, the issue is the air gap. If the sensor is backed out more than ¾ of a turn, the voltage generated may be too weak for the instrument panel to detect. Remove the sensor, re-establish tooth contact, and back out exactly ½ to ¾ turn only. Also confirm the connector is fully plugged in and the harness wires are intact.
Q: How can I electrically test this sensor?
A: Disconnect the sensor and use a multimeter on the resistance setting across the two connector pins. A healthy 240067A1 sensor typically reads between approximately 800 and 2,500 Ohms at room temperature. An open circuit (no continuity) or a near-zero reading indicates the sensor has failed. For a dynamic test, set the meter to AC voltage, reconnect the sensor, and crank the engine — you should measure a rising AC voltage as engine speed increases.
Q: Will a failed speed sensor stop my 905B or 906B from starting?
A: It depends on the specific engine control system fitted to your machine. On electronically governed engines, the ECU requires a valid RPM signal during cranking to enable fuel injection. If the sensor has failed completely, the engine may crank but not start, and the tachometer will show no movement during cranking. On mechanically governed engines, the sensor primarily drives the tachometer, and the engine will start and run without it — but the RPM gauge will remain at zero.
Q: The old sensor tip is covered in metal particles. Is this a concern?
A: Metal fuzz or particles stuck to the magnetic tip indicate the old sensor was installed with insufficient air gap and was in physical contact with the ring gear teeth. This grinds metal from both the gear and the sensor. Before installing the new sensor, inspect the ring gear teeth (through the port if visible) for excessive wear, scoring, or damage. Damaged gear teeth can produce a distorted signal and may require mechanical inspection by a qualified technician.
Q: Can I use this sensor on other Case or New Holland models?
A: The 240067A1 sensor may fit other machines that use the same engine family and sensor specification. However, always verify the OEM part number for your specific machine. Sensors that look identical externally can have different internal resistance values or connector keying, which will cause incorrect or no signal if mismatched. Cross-reference the part number, not just the physical appearance.
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