Rear Al Trailing Arm
 

I am changing my rear wheel bearings. I want to make a jack to jack them out. Looks easy enough to make. Does anyone know the ID of the backside (inside, CV Joint side) of the Al Trailing Arm? I have not taken it apart yet and I wanted to try to have all the tools without leaving in the middle of the job.

The new bearings are in the freezer already and I plan on using some heat too. :)

Thanks!