enlarging backing plate center

I need to enlarge the center holes on my backing plates. I need to gain about 1/8 inch total. I was thinking of using a carbide bit and a die grinder but was concerned about screwing it up. How critical is it that the hole stays perfectly centered?
Posted via Mobile Device

 

As long as you don't mess w/ the bolt holes use anything you want.:v6:

 

As long as the bearing/seal can pass through it with it bolted in place you'll be fine. I used a die grinder with carbide bit then cleaned up the edges with a stone for the Daughter's Jeep. Done it several times with other brake conversions. Not as clean as a lathe or mill but it works.

 

Thanks guys. I tried to get it done on a lathe but its just too big for what people have locally. I will try the bit on a die grinder and see what happens.

 

Fly cutter on a drill press? That would work if you secure the backing plate to another larger piece of steel.

 

maybe a spring loaded -3 stone cylinder hone tool. I'm sure one can make it work and just get the course grit (30 g?). Its designed to stay centered with equal radii pressure and not dependent on "static" center axis of rotation.

 

Modified that's a great idea!!!!! Thanks to all that replied
Posted via Mobile Device