The Reluctor Ring, or commonly called a "tone" ring, is a magnetic feedback device that usually surrounds a vehicle's axle or cv joint in the vicinity of the brake at each wheel. It is easily identified as a ring with notches cut into it, commonly about a half inch wide or slightly less, and 4.5-6" in diameter, depending on the size of the axle or cv joint in the vehicle. The "nodes" in the ring (spaces between the notches, pass by the magnet in the wheel speed sensor(s) that sits at a specific distance from the ring, creating an electrical impulse that is sent to the ABS controller, or Brake Control Module (BCM).
The ring and sensor count the nodes as they pass and calculate the wheel speed at the brake of each wheel. The vehicle speed sensor, in turn, should correspond with the reading at the wheel. The only time these values are NOT equal is when a wheel is locked up and sliding under hard braking conditions. In this condition, the BCM recognizes the values as inequal, and it engages the servo at the ABS unit, which allows the pressure in the brake lines to repeatedly "pulse" as the pressure is released.
Reluctor rings, like anything else, can go bad, often due to rust between the ring and the axle, causing the ring to split and to dislodge from its calibrated position and setting off the ABS light. Sometimes the ring can lodge against the spindle, steering knuckle, or hub assembly, either shattering the parts around it or even causing the wheel to lock up entirely. Adverse brake performance can also result.
Brake systems are THE SINGLE MOST important system in a vehicle, do NOT touch them unless you are trained or experienced, your life literally depends on it!
Tone rings are not always replaceable alone, as they're often part of the axle or cv assembly, so costs can vary widely. Replacing axles or CV joints often requires forces exceeding several hundred pounds and can be incredibly dangerous to perform.
Hope this information helps, and be safe.
-
-
In response to another question above, "I'm a lady... and can't afford to take it to a mechanic...."
-
-
...You have to do just like everyone else, cars are NOT gender-specific.
-
-
Or, ask your preferred mechanic about non-monetary payment methods, but be warned, answers will vary widely, you may not like the options, but EVERY mechanic appreciates creative solutions. Use your imagination, and Buon Appetito.
The Reluctor Ring, or commonly called a "tone" ring, is a magnetic feedback device that usually surrounds a vehicle's axle or cv joint in the vicinity of the brake at each wheel. It is easily identified as a ring with notches cut into it, commonly about a half inch wide or slightly less, and 4.5-6" in diameter, depending on the size of the axle or cv joint in the vehicle. The "nodes" in the ring (spaces between the notches, pass by the magnet in the wheel speed sensor(s) that sits at a specific distance from the ring, creating an electrical impulse that is sent to the ABS controller, or Brake Control Module (BCM).
The ring and sensor count the nodes as they pass and calculate the wheel speed at the brake of each wheel. The vehicle speed sensor, in turn, should correspond with the reading at the wheel. The only time these values are NOT equal is when a wheel is locked up and sliding under hard braking conditions. In this condition, the BCM recognizes the values as inequal, and it engages the servo at the ABS unit, which allows the pressure in the brake lines to repeatedly "pulse" as the pressure is released.
Reluctor rings, like anything else, can go bad, often due to rust between the ring and the axle, causing the ring to split and to dislodge from its calibrated position and setting off the ABS light. Sometimes the ring can lodge against the spindle, steering knuckle, or hub assembly, either shattering the parts around it or even causing the wheel to lock up entirely. Adverse brake performance can also result.
Brake systems are THE SINGLE MOST important system in a vehicle, do NOT touch them unless you are trained or experienced, your life literally depends on it!
Tone rings are not always replaceable alone, as they're often part of the axle or cv assembly, so costs can vary widely. Replacing axles or CV joints often requires forces exceeding several hundred pounds and can be incredibly dangerous to perform.
Hope this information helps, and be safe.
In response to another question above, "I'm a lady... and can't afford to take it to a mechanic...."
...You have to do just like everyone else, cars are NOT gender-specific.
Or, ask your preferred mechanic about non-monetary payment methods, but be warned, answers will vary widely, you may not like the options, but EVERY mechanic appreciates creative solutions. Use your imagination, and Buon Appetito.