# abs speed sensor front - I broke it - part umber please



## boyfriendmechanic (Aug 2, 2007)

Anyone know the part number? is it different from the A6?

I was replacing an outer CV boot, and all howto posts I found said to pull the sensor or it would be destroyed when pulling the joint/axle out of the steering knuckle. So I took out the 4mm (5mm?) bolt, and wiggled and wiggled. Ok I used a vice grip to wiggle it. Then the plastic broke and I was then looking at a shiny magnetic rod sticking out of the steering knuckle. 

Also, at first parts of the metal retainer broke off, from prying with a screwdriver. The metal plate that the hex bolt screws through, is this a retainer or part of the sensor? What is the part number on the retainer?

All that money I was saving by doing this job myself, well, maybe not so much of a savings now.:wave:
please help


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## boyfriendmechanic (Aug 2, 2007)

*internets research and a call to german autoparts.*

the part number is specific to the allroad and it is 4z7927803a. $191 each.
It is the same on both sides, in front anyway. Thank the height adjustable suspension for the specific part needed. 

I just still need to know, do you have to pull this sensor to get the wheel hub off? Or can you take the hub out without damaging the sensor, and drive the sensor out?
This article is for a Passat, but says in Step 7:

"At the wheel hub, pull out the wheel speed sensor, located near the brake calipers - this step is often overlooked at auto shops. On these cars, pulling out the driveaxle with the wheel speed sensor in place will destroy the sensor and require replacement. (illustration)"

http://www.taligentx.com/passat/maintenance/cvjoints/

This was not so helpful for the speed sensor:
http://www.audizine.com/forum/showthread.php/391941-ABS-wheel-speed-sensor-removal

This is a nice summary of how to remove the CV joint, but no mention of the speed sensor.
http://www.audiworld.com/tech/wheel37.shtml

Apparently, you can drive the speed sensor out from the inside if the sensor will not pull out
Here is says you can drive the stuck sensor out from the inside of the steering knuckle.
- It seems you need to have taken the cv joint out of the hub first which contradicts the first post/link above.

"Good luck - it's likey to break. Only foolproof way I've found was to disassemble enough to get the axle out of the hub so you can look inside. Find the face of the sensor, put a 12" extension against it, and tap it out."

http://www.audiforums.com/forum/b5-models-69/removing-front-abs-sensor-148033/

hope this helps others...
I have a used one shipped to me for $47


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