This is a little newer than what I'm familiar with. Do you have a manual for it?
https://www.singer.com/support
I also found
http://parts.singerco.com/CPpartChar..._9034_9044.pdf It looks like the tension module is one unit and isn't broken out. "137574-001" is the part number. I also noticed that it was called "demand responsive needle tension system." I don't know if it would have different insides than the older fashioned tension assemblies.
I also noticed that it takes Apollo bobbins which are slightly different than a class 66 bobbin. I know someone had problems until they actually got the correct bobbin.
http://www.singersewinginfo.co.uk/bobbins/ is where I found measurements for the different bobbins.
Janey - Neat people never make the exciting discoveries I do.