Looks like you are correct, you could try to disassemble your old hub assembly and press on the flange for the wheel. I don't think its worth it though.
The correct Timken Part# for the rear hub assembly (including the flange and wheel studs) on the R51 is HA500701. (Courtesy of RockAuto. They do list the BM500022 and show a cross to the 2008 R51, and its $50 vs $115 for the complete assembly.)
Get the full assembly, you'll thank me later...
Also, stay away from the Moog 541003, I had a major issue with this rear hub assembly a few weeks ago, and the driveshaft would not fit through it. Changed to Mevotech, and problem went away. Apparently Moog isn't the best anymore.
I like Timken though.
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