Hello everyone!

I'm in the process of changing the O2 sensor (done ) on my 535i and am also planning to replace the center bearing. After removing the exhaust system today, I found that my transmission output flange seal has been leaking slightly. This is evident by a thin ring of transmission fluid on the heat shield surrounding the area. From various sources I've gathered that to replace the seal I'll need to find a thin-wall 30 mm socket. I do not have the tools to machine down a regular socket, although I do have a die grinder. Is there a source for these sockets either in regular retail stores or online? I believe Armstrong Tools made/makes a socket that works for this with a part number 12-238. I can't however find anyone who sells these sockets to the public. It would be disappointing to have to let this leak continue just because I can't find the right tool for the collar nut. All advice and suggestions are appreciated!

Best wishes.