I'll be replacing a rear wheel bearing soon, the roar is getting annoying. First question is after I'm done whats the torque spec on the axle bolt?

The notorious abs and brake light problem came up and I replaced the module with one from a salvaged A4. This fixed the problem for about 8 months but now it's back. I then had the original module rebuilt and switched it back in thinking problem solved but the damn light still came on. So since its not the module it has to be a speed sensor. Can a bad wheel bearing trip the wheel speed sensor?

Quote from ecstuning. True or BS?

 

To answer the second question first, yes - a bad wheel bearing can ruin the wheelspeed (ABS) sensor. When the bearing goes bad, there's a LOT of heat in the hub from it and that can eventually take out the ABS sensor.

The torque spec is 85 ft-lbs + 180 degree turn, according to this DIY:

http://www.audiworld.com/tech/wheel.html

 

That's what I torqued mine to.

Since the ABS sensors opperate by magnetics if your bad wheel bearing has shed some metal shavings those could be screwing with it. Just clean the whole thing really well when you do the bearing and see if that helps.

 

If you have a vag com you can monitor all four wheel speed sensors while you are driving. If one of them isn't working correctly you found your problem.

 

Thanks guys. Before I do the bearing I'll have it scanned to confirm if the sensor is bad at the same hub.