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Z3 Gap between ABS sensor and hub ring?

5529 Views 12 Replies 3 Participants Last post by  wifesauto
I've put in a new sensor as the old one was badly worn and the tip was broken - plus my ABS light was on.

Put the new sensor in, but noticed the hub ring is scraping past the new sensor.

Does anyone know what kind of gap between sensor and hub ring there should be?

Just spent an hour googling this and got nothing.
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Yeah, I hope I would have thought of that if the other side was intact. I've taken that apart too.

However, when I put the hub back on and turn by hand, the clearance is a lit more than on the other side.

So I don't know which side is the correct one. I would have thought there would be some sort of optimum gap clearance.
measure the oposite wheel
i have never seen one adjustable. are yours ?
No.

The rust under the notched rim on the hub seems to have expanded it's size - so it rubs against the sensor.

Just wondering if it's time for new hubs or if the fact it rubs against the sensor isn't a big issue.
i have never seen one adjustable. are yours ?
According to the Bentley Z3 manual (you do have one, don't you?), there is no spec or adjustment for the wheel speed sensor gap. It appears that if a pulse wheel is damaged (which would seem to be the problem if the pulse wheel only contacts the sensor during part of the rotation), you replace the part that includes the pulse wheel (front wheel hub or rear outer CV joint).
Yeah, I guess that's common sense.

Might look into new hubs. £35 on ebay, not too bad.

Cheers for your help.
it should NOT rub
Manuals? na mate, that's for women.

Actually I have a 318 e36 too. I looked through the manual for that, but didn't have much info.

So am I to understand from your post that the sensor IS supposed to be in contact with the hub rim?
According to the Bentley Z3 manual (you do have one, don't you?), there is no spec or adjustment for the wheel speed sensor gap. It appears that if a pulse wheel is damaged (which would seem to be the problem if the pulse wheel only contacts the sensor during part of the rotation), you replace the part that includes the pulse wheel (front wheel hub or rear outer CV joint).
And for people who have to ask elementary questions about their cars. ;)

Manuals? na mate, that's for women.
So am I to understand from your post that the sensor IS supposed to be in contact with the hub rim?
That's what you got from my post? Do you think the design is for the sensor to contact the pulse wheel for part of the rotation? Does that seem right? No, the speed sensor should NOT contact the pulse wheel. It should at a close tolerance so that the sensor can sense the pulse wheel passing by it.
To be fair, that's what you intimated in your previous post

And for people who have to ask elementary questions about their cars. ;)

That's what you got from my post? Do you think the design is for the sensor to contact the pulse wheel for part of the rotation? Does that seem right? No, the speed sensor should NOT contact the pulse wheel. It should at a close tolerance so that the sensor can sense the pulse wheel passing by it.
According to the Bentley Z3 manual (you do have one, don't you?), there is no spec or adjustment for the wheel speed sensor gap. It appears that if a pulse wheel is damaged (which would seem to be the problem if the pulse wheel only contacts the sensor during part of the rotation), you replace the part that includes the pulse wheel (front wheel hub or rear outer CV joint).
Your wording would suggest it needs to contact on full rotation.

But yeah, common sense would suggest there should be no contact - just hovering over the hub.
To be really fair, it only seems that way to someone who has no idea how a wheel speed sensor works. ;)

The other possible meaning for "no spec or adjustment for the wheel speed sensor gap" is that the gap is not adjustable.

To be fair, that's what you intimated in your previous post
Your wording would suggest it needs to contact on full rotation.
Two parts, with no rollers or other moving components between them, and no lubrication between them, contacting each other during the full rotation where one moves and the other does not move . . . what might the result be?

But yeah, common sense would suggest there should be no contact - just hovering over the hub.
Yeah, common sense would seem to suggest that. ;)

Common sense would also suggest that you need to get a Bentley manual for your car.

Well, now that you know, good luck.
my WAG is .020/.050 and you would need brass feeler gauges
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