Audi Q5 ABS/Speed sensor is stuck...

[paalanm]

Hi everyone!
Thanks to this great tool, I was able to find the cause of the error messages on my 2010 Audi Q5 3.0 TDI (ESP/ABS fault, Parking brake malfunction). It pointed directly to the right front wheel ABS/Speed sensor. So, I ordered the new part, though it NOT turned out to be an original Bosch part... However, this is not the issue right now, because when I tried to remove the old part/sensor, the sensor itself (of course...) remained stuck. I tried to drill it out, but I'm very concerned how far I can drill, I'm concerned to drill too much. And - if I'm drilling exactly the right length, what about the remains that might reside inside the hub? I think I will have to remove the hub to check for remains, clear the hole for the sensor and reassemble everything.
Can anyone (please!) give me some advice on how to disassemble and reassemble the hub, and - last but not least - give me a hunch of what torque to use when reassembly the upper. middle and lower bolts?
I've watched this video regarding this, FYI:

Kind regards,
Paal.

 

[stefdds]

HI Paal, I'm glad to hear that you realized you can't drill to far into the sensor location hole ; otherwise you risk hitting the face of the wheel bearing which contains the tone ring within it!
One way would be to purchase the new ABS wheel speed sensor and measure your depth by comparing your measurements using the new sensor to gauge your depth. Only drill a hole large enough to place a large screw into and then you can pull or twist (slightly)on the screw to get the body of the sensor loose-with a vise grips. Do not twist the sensor past 90 degrees, as there is a half diameter piece which extends and is parallel to the wheel bearing face and you don't want to "turn" the end of the sensor into the ring face of the bearing.

I did post some pictures of this issue here on the RT forum. It will give you some insight as to the extension of the sensor in relation to the bearing. Search my posts, I think you would find that thread helpful ; its not my thread, I only answered/contributed to it.

As far as the hub, you do not need to pull the bearing apart (and ruin it) ; there are four bolts on the back side of the steering knuckle, once you remove those four bolts, plus the main drive shaft bolt (in the center of the axle) you will be able to remove the hub+bearing+mounting flange all together. Now, that (steel) flange fits precisely to the (Aluminum) knuckle , so you most likely will have to carefully pry and wedge between the steel bearing flange and knuckle to separate it. Do not pull on the hub. They corrode together because of the dissimilar metals. Be patient, and use some anti-seize compound when you clean things up and reassemble.

I'll see if I can find that post/picture also. Also, that video is not representative of your steering knuckle or bearing arrangement.

see post #18 for the hub assembly: note the four threaded holes in the flange
and pictured is the hub(face down) plus the steel flange (four holes) containing the bearing.

Wheel speed sensor / ABS for 2008 Audi A6 3.2: Where do I go from here?

I replaced all the struts, the front left wheel bearing, and all front upper control arms on my vehicle a few months ago. In the process of that work, I found that both front upper control arm pinch bolts had completely fused with the knuckles. I had to drill them out, somewhat crudely, to...

forums.ross-tech.com

Here is a video representative of your knuckle and bearing. You don't have to follow this method and you don't need this beautiful equipment to remove your assembly; it is only to give you insight of the parts you have.
Note times: 30sec. , 54sec, 1:07, 1:46, 1: 53 , four bolts removed 2:11 , flange getting bolted back on 2:50.

In this video the tech. separated the hub from the bearing and flange ; to be clear, you are Not doing that. Because of those four bolts you will be able to separate the hub assembly from the knuckle , but it will be stuck - you need to separate the complete assembly from the knuckle.

 

[paalanm]

Thanks a lot for your reply Stefan, highly appreciated!
I've decided to let a local professional do the job, I haven't the time nor the tools/skills to do this myself. He will disassemble what's needed and remove the remains from the inside, which I believe it's the only right way to fix this. He's also a sunroof specialist, so I've asked him to fix the noise from the sunroof as well. I'll try to keep you posted.
Kind regards,
Paal.