[ResQU]

Front ABS/Speed sensor position

Hello all,
Well I thought I knew what I was doing but while removing the front wheel to perform various tasks, I loosened nd removed the left side threaded axel sleeve. Once I realize I didn’t need to do that,I figured I’d be able to just find info on how to reset it’s position. No luck, it’s not listed in the repair CD or manual I have. Does anyone know the proper gap between the ABS/Speed pick up sensor and it’s indicating ring? The only information I can find is that the left side axel sleeve is set to provide the proper spacing, just no information on what that is supposed to be. Thanks

 

[Meese]

I believe the left side threaded sleeve is simply pushed all the way in until it stops, then tightened down.

As you've discovered, there's no reason to loosen this up for normal maintenance or wheel changes.

 

[ResQU]

I believe the left side threaded sleeve is simply pushed all the way in until it stops, then tightened down.

As you've discovered, there's no reason to loosen this up for normal maintenance or wheel changes.

That’s what I’m going with too. As it is, that’s very close to the sensor...less than a 1/16”. I’m thinking it’s a simple magnetic/hall type sensor. So close enough to show a reading display is probably good. Thanks again

 

[HunterSr]

Front ABS/Speed sensor position

Hello all,
Well I thought I knew what I was doing but while removing the front wheel to perform various tasks, I loosened nd removed the left side threaded axel sleeve. Once I realize I didn’t need to do that,I figured I’d be able to just find info on how to reset it’s position. No luck, it’s not listed in the repair CD or manual I have. Does anyone know the proper gap between the ABS/Speed pick up sensor and it’s indicating ring? The only information I can find is that the left side axel sleeve is set to provide the proper spacing, just no information on what that is supposed to be. Thanks

Since the purpose of the LH threaded sleeve is to set and adjust the ABS sensor gap, I believe it's important to use the sleeve as intended (and not just shove it all the way in and hope for the best). I could find no spec. for this front sensor gap either so what I do is reference the factory set gap on my rear ABS sensor. On my '13 GT the rear ABS sensor factory set gap measures about 0.65mm. So, when I have to replace a front wheel, front wheel bearings or accidently loosen the front LH sleeve I set the front ABS sensor gap equal to the rear ABS sensor gap (in my case 0.65mm).

 

[1004ron]

I believe the left side threaded sleeve is simply pushed all the way in until it stops, then tightened down.

As you've discovered, there's no reason to loosen this up for normal maintenance or wheel changes.

That's also what I believe, and from many posts on this subject its the general consensus.

 

[1004ron]

Since the purpose of the LH threaded sleeve is to set and adjust the ABS sensor gap

I've searched the DVD service manual and cannot find any reference indicating that it is positioned to "adjust" the sensor gap.

 

[HunterSr]

I've searched the DVD service manual and cannot find any reference indicating that it is positioned to "adjust" the sensor gap.

My DVD manual shows the following highlighted in yellow. I took it to mean that the LH sleeve is what adjusts the ABS sensor gap. I may very well be wrong, I often am .

 

[1004ron]

HunterSr

Its a little ambiguous with the comment "correctly aligned" which we've all learnt to be fully inserted up to its shoulder - if there was an "adjustment" then I'd expect the procedure with values would be presented in the manual.

 

[coyotek]

Fully seated. Sets the spacing for the wheel. And everything else is fine. It is not an adjustment.

 

[HunterSr]

HunterSr

Its a little ambiguous with the comment "correctly aligned" which we've all learnt to be fully inserted up to its shoulder - if there was an "adjustment" then I'd expect the procedure with values would be presented in the manual.

I get that ambiguity, the manual doesn't show an adjustment procedure, but it also doesn't tell us to push the threaded bush all the way in before tightening the clamping screws. It does tell us that moving the threaded bush "can cause the ABS to malfunction" (sensor too far from ring), "or allow the sensor to be damaged" (sensor too close to ring). My thought is that the Germans don't build anything without volumes of specifications and the front ABS air gap is no exception, they just didn't share that spec. with us and there is only one way to adjust that gap, with the threaded bush. Anyway, I do adjust the air gap on my front sensor and it works just fine. I was just sharing some info on my DIY procedures after completing some work recently, just in case anyone was interested in how other folks do stuff.

 

[1004ron]

Anyway, I do adjust the air gap on my front sensor and it works just fine.

And if you fully seated it, like the rest of us do, I have no doubt yours would also be working just fine - for me I don't see the need for complication.

 

[HunterSr]

And if you fully seated it, like the rest of us do, I have no doubt yours would also be working just fine - for me I don't see the need for complication.

You’re right, I have had mine fully seated and it worked fine. But with my wheel assembly pushed all the way over to the right the front sensor air gap was huge compared to the smaller rear sensor gap so that’s why I adjust it. Thanks for your thoughts.

 

[coyotek]

You’re right, I have had mine fully seated and it worked fine. But with my wheel assembly pushed all the way over to the right the front sensor air gap was huge compared to the smaller rear sensor gap so that’s why I adjust it. Thanks for your thoughts.

You don't have a clue. Lol

 

[HunterSr]

You don't have a clue. Lol

My engine would run fine if the valve lash gaps were too large, but I adjust those too.

 

[rhbike]

My engine would run fine if the valve lash gaps were too large, but I adjust those too.

Shifting the wheel to adjust the ABS sensor gap will shift the alignment of the rotors to the calipers too.

The left side axle sleeve on my K16 came from the factory fully seated. Like others, I have not seen anything in the DVD service manual that says to adjust this sleeve, as I believe they designed the alignment of the wheel, rotors, calipers, ABS ring and ABS sensor on the presumption that the sleeve is to be fully seated.

 

[Gunnert]

You guys need to lighten up on @HunterSr , If he wants to adjust his front wheel then he should adjust his front wheel. He obviously knows more about his bike than BMW or the members on the forum that have been wrenching on these machines for years. Also, Hunter, thanks for your input on valve lash. I've been taught my whole life that if valve lash was too large I'd hear a clatter and the loose valve would damage the valve seat and camshaft. I learn something new everyday....

Duane

 

[HunterSr]

Shifting the wheel to adjust the ABS sensor gap will shift the alignment of the rotors to the calipers too.

Great observation rhbike, I also considered this but the caliper pistons and brake pads are both self-adjusting, whereas the ABS sensor gap is not. My calipers just didn't seem to care that my rotors moved 0.50mm (0.020") to the left.