2WD ABS - how it works

[Hartman]

Hey guys, I'm a little confused about how the ABS system on a 2WD works. According to Ford Part Network's diagram, there is a sensor ring that goes on the spindle between the inner wheel bearing and the rotor. I got that part, but it doesn't seem to fit correctly between the bearing and the rotor. On my 2WD rotors, there's a little ring already pressed in there for the ABS system. My question is, do both of these rings work simultaneously, or is only one of the rings neccessary? Pictured below is the sensor ring on the left and the rotor with the ring already in it on the right.

 

[Hartman]

C'mon jerkys, I know someone knows about this.

 

[Brans Freestyle]

I'm not too sure about the ABS system, but when I change my rotors and repack the bearings, all I had to do was put the 2 bearings in and mount it to the spindle, there was no other ring to put on. My rotors however do have a ring that looks just like the one pictured on the left, but already mounted to the rotor, and that didn't come off.

 

[Hartman]

Ok so you have the left ring on, but there's nothing behind that ring that might look like the ring pictured on the right?

 

[Alec]

I think there's probably only 1 ring. The magnetic sensor that plugs into the spindle senses how many and how fast the ring's teeth pass.

I could be wrong though, but that's how a crank position sensor works and it's a similar system.

 

[Brans Freestyle]

Ok so you have the left ring on, but there's nothing behind that ring that might look like the ring pictured on the right?

I'm not sure, it was a while ago when I changed brakes and my rotors so I can't remember.

 

[Sallad420]

Mount it without the extra ring, keeping the built in ring only, and lock up your brakes on a gravel road or something, if the ABS kicks in, problem solved!

 

[Hartman]

Ok I'm pretty sure now that the ring in the rotor is the only one needed. Kind of sucks because that seperate ring cost $25 and can't be returned since I opened the bag it was in. :frustrate

 

[double_take]

I was looking at my wifes truck the other day. She has a 2WD 98 Sport. Hers had rings that looked like the one on the left of the picture. But she didn't have anything that looked like the one on the right.

My conclusion. Perhaps the one you have on there now is an aftermarket ring since it is obviosly an aftermarket slotted rotor.

All I can say for sure is the stock 98 2WD has the ring shown on the left. It has this on both front rotors and a sendor in the rear diff fer the rear wheels.