Does anyone know of a supplier or vendor of penta-head sockets (male and female)? The ABS sensor on my Timken hubs are secured with a bolt with a head that has a 5 sided hole; i.e. for a five-sided "hex key."

 

Vise grips when you don't have the proper tool tend to work nicely.

 

Take your pick of google results for '5 point bit set'. They're available from a number of sources.

I will mention that these fasteners are used because there isn't anything serviceable inside. More often than not, these bolts will snap off anyway.

 

Yes, I've learned that the penta-head screws are intended as tamper-resistant applications. The reason I thought it not unseasonable to remove is because my GM manual has a step in the instructions for the front wheel hub removal that says to remove the sensor. Then I found that these speed sensors can be purchased separately that implies that they are intended to be removed. https://www.gmpartscenter.net/oem-pa...yABEgLnGfD_BwE

 

I haven't found 5 head screws holding in the sensors themselves, only the shield on the back side of the hub which could have been from a different application.

Hopefully, in your case, the larger screw that holds the sensor comes out.

The next problem you will run into is whether the sensor itself wants to come out. The tip of the sensor tends to stick in the bore and break off if pried on too much.

I would test the sensor before attempting to remove it. It is a fairly simple hall-effect device. You should see a minimum 200mV-AC across the pins when spinning the hub by hand. Frequency will depend on how fast it is spinning. Of all of the times I have replaced a sensor, I have replaced the entire hub shortly thereafter. There are only a few things that can change the sensor output voltage which is driven by the sensor air-gap to the tone ring; a bad bearing and corrosion moving the sensor are the two most common with bearing failure to be MUCH more common.

 

When I needed to remove the tamper proof Torx on my ABS module, I sliced a slot in it with a dremel and used a blade screwdriver from there. Don't know it that job will help in your case though.
putts