AC Voltage At Rear Wheel Speed Sensor

[Gio93z]

RE: 93 Camaro LT1 + ABS Problem


I have a specific ABS Problem but my first question I need answered is this...

In regards to any wheel speed sensor.....does the air gap between the reluctor ring and the magnetic pick up directly affect AC voltage??

Basically, if there is too great of an air gap, can the AC voltage generated not be sufficient

Greater the air gap = minimal ability for WSS to pick up a reading

?

Thanks

[ib4200]

yeah get it as close as possible without hitting for the clearest signal

[Gio93z]

well in that case.....my ABS light has been on for about 6 years now....I have no rear wheel speed signal......i just now finally decided I would take a look at it.....i have changed my EBCM and my rear wheel speed sensor in my diff. (a 2nd time).......i have check my wiring front to back about 5 times over.....and i have no interior in the car at the moment because im putting a new carpet in..so i have clear access at my wiring......absolutely everything checks out ok.....the only thing that is odd, is that when i spin the rear wheels with my meter hooked up to my rear WSS.....i SHOULD be getting at least 100mv....but im only topping out at about 6mv....which is leading me to belive something is up with my air gap inside the diff....since im getting a reading but it is insufficient

the missing link is that at almost the same time about 6 years ago when the ABS light came up....I had the rear end ring and pinion and carrier redone....so what im saying is that maybe it is possible that the new rear end stuff he used had a slightly different reluctor ring on it .....

[V]

or, they never put the abs ring on the carrier at all, i think thats a possibility

[Gio93z]

yea thats what i initially thought, but i've done a couple diff fluid changes and have checked to make sure the pick up ring is actually there.....it is.......but i didnt really pay attention to the air gap......

[Gio93z]

so i checked everything out....i have a problem with my rear end reluctor pick -up.....i saw a few picks of some 93 - 97 rears and the reluctor looks like maybe its 1/2" wide....anyway, when i pull my rear abs sensor and peek inside, it looks like my reluctor pick up is only about half that widtch and the magnet on the abs sensor is not directly above the pick-up....so when i went from 2.73:1 to 3.73:1 and had the carrier changed, is it possible that either i needed a different, wider pick-up reluctor or, he pressed my reluctor on too far and did not center it directly below the magnet on the ans sensor..........


long story short.....am i going back to my trans shop to have a word with him?

[alamantia]

There are different width reluctor wheels for 2 and 3 series carriers

[Gio93z]

...it's goin back to the trans shop this week and he is gonna fix it for me...he seemed to know what i was talking about o hopefully all goes well - thanks


...lets go rangers

[Troy]

I don't see how you can press the reluctor ring on too far, it should sit on the shoulder of the axle, no?

On my LS1 the sensor magnet covers approx 2/3rds of the ring if that helps...

[sweetbmxrider]

Originally Posted by Troy

I don't see how you can press the reluctor ring on too far, it should sit on the shoulder of the axle, no?

On my LS1 the sensor magnet covers approx 2/3rds of the ring if that helps...

3 channel abs (non-traction control cars) have 1 single reluctor wheel on the ring gear.

[Gio93z]

i brought it to the shop and he moved the reluctor about 1/4"....i now have rear wheel speed......now i have a secondary problem...i have a 95 and 96 code with a flashing abs light......i wonder if it has to do with the newer style SS spoiler i have on that uses the LED 3rd brake light instead of traditional bulbs......ah thats for another thread......

[sweetbmxrider]

http://shbox.com/1/relay_for_ss_spoiler.jpg

[Gio93z]

i thought the LED CHMSL may be causing a problem.....can i measure the resistance of 85 and 86 on the relay and use an inline resistor in the wire which feeds brake light voltage to my ebcm?? or is that not practical.......

thanks for the insight and help

[sweetbmxrider]

no problem. personally, thats what i would do. shoebox says a regular resistor won't dissipate heat quick enough and may burn up so he recommends the relay for the resistance.