64MT412M Speedometer Tachometer Speed Sensor Replacement for Mack Truck DM RD CH MR CL 505-5507 845070 Dorman Compatible

Product Overview The 64MT412M / 505-5507 Vehicle Speedometer and Tachometer Speed Sensor is a premium commercial-grade heavy-duty fleet tracking component engineered explicitly as a high-reliability replacement for Mack Class 8 Commercial Trucks, Heavy Dump Trucks, and Vocational Vehicles. Threaded directly into the primary transmission tail-housing or adjacent to the main flywheel timing casing, this high-accuracy inductive magnetic pickup (MPU) sensor monitors the real-time velocity of the passing gear teeth. By converting physical revolutions into consistent, interference-free digital pulse telemetry streams straight to the truck’s main Engine Control Module (ECM) and cockpit instrument cluster, it restores erratic speedometer and tachometer readouts, ensures smooth automated gear shifting parameters, and stabilizes cruise control safety under volatile heavy hauling loads. Technical Specifications Primary Mack Truck Genuine OE Catalog Code: 64MT412M Cross-Reference Industry Standard Dorman Code: 505-5507, 5055507 Historical Legacy Factory Part Reference: 845070 Sensor Modality: High-Sensitivity Inductive Electromagnetic Proximity Pickup / Flywheel Speed Sensor Primary Function: Transmission Output Speed, Drivetrain Velocity Tracking, Instrument Cluster Speedometer Calibration, and Associated Engine Timing Feedback Housing Architecture: Anti-Magnetic Corrosion-Resistant Threaded Metallic Barrel with Precision Built-in Hex Nut Terminal Layout: OEM-Pattern Heavy Duty Weatherproof and Waterproof Sealed Connector Interface Condition: 100% Brand New Premium Semi-Truck Aftermarket Replacement Assembly Broad Vehicle & Equipment Compatibility This universal heavy machinery speed sender delivers exact original factory dimensional profiles and voltage signaling compliance across multiple eras of Mack’s most legendary vocational workhorses and long-haul highway semi-tractors: Equipment Family Compatible Mack Models & Heavy Duty Drivetrain Fits Mack Vocational Dump & Mixer Trucks Mack RD Series, DM Series, and RB Series heavy construction dump trucks, concrete mixers, and severe-duty aggregate haulers Mack Highway Logistics Fleets Mack CH Series (such as CH613) and CL Series long-haul traditional semi-tractors running manual or automated manual transmissions Mack Cabover & Refuse Fleets Mack MR Series low-cab-forward refuse collection fleets and municipal utility units tracking driveline RPM telemetry Key Benefits Immediate Fleet System Adaptation: Pre-calibrated strictly to native Mack diagnostic electrical thresholds, enabling immediate active cockpit fault code clearing (such as erratic odometer jump codes or transmission loop errors) without requiring dealer computer updates. Severe Fleet Environment Protection: Hardened solid-state structural housing easily handles extreme under-chassis transmission oil heat spikes, aggressive winter road salt slurry soaking, abrasive road dust sand-blasting, and violent chassis tremors. Critical Drivetrain Operational Errors Cured: Swiftly addresses severe truck malfunctions including completely dead or erratically dropping dashboard speedometer needles, jumping tachometer pointers, cruise control dropping out under load, or harsh automatic transmission gear hunting slips. Drop-In Leak-Proof Mechanical Installation: Fabricated to precise original physical factory blueprints with clean, crisp thread profiles to guarantee a tight, vibration-proof physical lock that completely stops gear oil weeping around the casing port. Cross-Reference Guide This industrial closed-loop commercial fleet speed sensor interchanges directly with the following manufacturer and logistics catalog indices: MACK TRUCKS (GENUINE REFERENCE): 64MT412M, 845070 DORMAN AFTERMARKET SYSTEM: 505-5507, 5055507 Technical Fleet Index HEAVY TRUCK ELECTRICAL CODES: Premium high-durability replacement automation electronics calibrated to match original factory circuit protection configurations Maintenance Tip: If your classic Mack RD Dump Truck or CH613 Semi-Tractor suddenly suffers from a completely dead or erratically jumping dashboard speedometer needle, experiences harsh, jerky shifting through its transmission gear cycles, or unexpectedly kicks you out of cruise control while hauling a heavy load, evaluate this 64MT412M sensor immediately. Because this component is threaded directly into the high-stress transmission output shell or near the main flywheel housing, its magnetic inductive core naturally attracts a thick insulation blanket of fine metallic gear wear filings and carbon oil sludge over hundreds of thousands of rigorous operational miles. This slurry layer heavily dampens the digital signal pulse loops, leading the ECM to drop telemetry synchronization. Before threading this new replacement probe down, always wipe the mounting socket perfectly clean, check the wire lead loom for harness chafing against hot exhaust shields, and ensure a 100% bone-dry connector click-lock to secure absolute automation tracking.