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Brand: C.OEFT
OE numbers:27000-RDS-305
EAProduct Name: Transmission Valve
Compatible model:/
Product status: Remanufactured
Product weight: 2.2000KG
Packaging size: 28*17*15 cm
Product packaging:Neutral Packaging
Car Series: Janpanese
Car Type: for Honda Acura Spirior
1. Gear-Shifting Oil Circuit Switching for Precise Gear Engagement
The 27000-RDS-305 solenoid valve acts as the "switch executor" for the transmission’s internal oil circuits, directly controlling the engagement and disengagement of clutches and brakes corresponding to different gears. When the TCU detects a gear-shifting demand (e.g., shifting from 2nd gear to 3rd gear in a 5-speed automatic transmission), it sends a pulsed electrical signal to the solenoid valve’s coil. The coil instantly generates a magnetic field, driving the spool to move axially and opening the oil passage leading to the 3rd gear clutch. At the same time, it adjusts the oil discharge speed of the 2nd gear clutch through a linked pressure relief structure, ensuring the 2nd gear clutch disengages smoothly while the 3rd gear clutch engages gradually.
For example, in Honda’s Accord (9th generation) equipped with the 5AT transmission (to which the 27000-RDS-305 solenoid valve is adapted), when the vehicle accelerates from 40 km/h to 60 km/h, the TCU activates this solenoid valve. It precisely controls the hydraulic oil flow to the 3rd gear clutch, filling the clutch oil chamber within 0.15 seconds and completing the gear shift without obvious 顿挫 (jerking). When de-energized, the built-in return spring quickly resets the spool, closing the target oil circuit to prevent abnormal pressure buildup, ensuring the transmission’s standby state is stable and free from oil leakage risks.
2. Linear Hydraulic Pressure Regulation for Adaptive Working Conditions
A key functional advantage of the 27000-RDS-305 solenoid valve lies in its high-precision linear pressure regulation capability, which adapts to different driving conditions (light load, heavy load, cold start) by dynamically adjusting hydraulic pressure. It adopts a proportional control mode: the TCU adjusts the duty cycle of the coil current (ranging from 0% to 100%) to change the spool’s opening degree, thereby controlling the hydraulic oil pressure in the clutch/brake oil chamber with an accuracy of ±0.08 MPa.
During light-load driving (e.g., constant-speed cruising at 80 km/h in 5th gear), the solenoid valve reduces the clutch pressure to 1.0-1.3 MPa, minimizing friction loss between the clutch plates and improving fuel economy—this can reduce the vehicle’s fuel consumption by approximately 5% compared to fixed-pressure control. When under heavy load (e.g., accelerating uphill with a full load), it increases the pressure to 2.2-2.5 MPa, ensuring the clutch plates are tightly engaged to avoid slipping and torque loss. For low-temperature cold starts (below -15℃), the solenoid valve first maintains a low pressure (0.7-0.9 MPa) to allow the clutch plates to "run-in" and warm up, then gradually increases the pressure to the normal range, preventing clutch damage caused by excessive cold friction. This adaptive pressure regulation not only enhances driving comfort but also extends the service life of transmission components.
1. High Compatibility with Honda and Honda Joint-Venture Models
The 27000-RDS-305 solenoid valve is mainly tailored for Honda’s 5-speed and 6-speed automatic transmissions, widely used in Honda’s global models and domestic Sino-Honda joint-venture vehicles, covering a variety of vehicle types:
Honda Global Model Adaptation: It is fully compatible with Honda’s overseas models such as the Honda Accord (8th/9th generations), Civic (9th generation), and CR-V (3rd/4th generations) equipped with the 5AT (e.g., Honda’s RB3 transmission) or 6AT (e.g., GP1 transmission). Its electrical parameters (coil resistance: 11±0.4 Ω, operating voltage: 12V DC) and structural dimensions (installation hole spacing: 25±0.1 mm) perfectly match the original transmission valve body, requiring no modification during replacement.
Domestic Joint-Venture Model Adaptation: In China, it is a standard component for Guangqi Honda’s Accord, Odyssey, and Dongfeng Honda’s CR-V, Civic models. These joint-venture models adhere to Honda’s global quality standards, and the 27000-RDS-305 solenoid valve passes Honda’s strict validation tests (including 5,000-hour high-temperature durability test, 10,000-cycle pressure impact test), ensuring consistent performance with imported original parts.
Transmission Version Adaptability: It can adapt to different torque versions of Honda’s automatic transmissions (e.g., the 5AT transmission has a low-torque version for 1.8L engines and a high-torque version for 2.4L engines) through minor adjustments to the spool’s flow coefficient. This avoids the need for developing multiple solenoid valve models, reducing inventory pressure for repair shops and manufacturers.
2. High Reliability and Extreme Environment Durability
High-Quality Material Selection: The 27000-RDS-305 solenoid valve’s valve body is made of high-strength aluminum alloy (ADC12) through precision die-casting, which has excellent corrosion resistance and impact resistance—able to withstand long-term immersion in transmission oil and temperature changes (-40℃ to 140℃) without deformation. The spool is made of high-hardness stainless steel (SUS304) and undergoes precision grinding, with a surface roughness of Ra 0.02 μm, ensuring smooth movement and low wear. The sealing ring is made of nitrile rubber (NBR) with oil-resistant and high-temperature-resistant properties, which can maintain good sealing performance even at 140℃, avoiding oil leakage.
Anti-Pollution and Anti-Jamming Design: The solenoid valve’s oil inlet is integrated with a 15 μm precision filter screen (filtration efficiency ≥99%) to block metal chips, sludge, and other impurities in the transmission oil from entering the valve body and causing spool jamming. Additionally, the valve body’s internal oil passage is designed with a smooth arc transition, reducing oil flow turbulence and preventing impurity accumulation. In Honda’s standard contamination test (adding 30 mg/L of metal debris to the transmission oil), the solenoid valve maintains stable performance for 300 hours without jamming or pressure deviation, ensuring reliable operation in harsh working environments.
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