Shuttle lever is frozen on our M 8540 NOT hydrostatic, but regular shuttle

SOURCE: shuttle alignment and assembly

The shuttle/race/bobbin system shouldn't really be taken apart by the average user. Unfortunately, your chances of ever getting it back together properly so the machine will sew (this is the timing of the machine) are very slim. You'll need to take it to a sewing machine technician. I would recommend an authorized Pfaff tech as they'll be sure to have the proper tools to do this correctly - won't be inexpensive but will be worth it. Most "neighborhood sewing machine repair folks" don't have experience on computer machines. Resetting timing on a computer machine isn't the same as the old mechanicals and requires some expertise.

SOURCE: how to re-insert bobbin shuttle

maybe one of the parts diagrams at the Singer site would help? or us the contact there?

SOURCE: Kenmore 385. 11607 needle jams into shuttle or shuttle race

I had the same problem with cleaning and jamming and this might sound silly, but when you're in the middle of trying to fix it remember to look up see that it is threaded up top. I did everything the pp's suggested and when they didn't work I realized the top thread wasn't still threaded around the tension thing anymore. After rethreading it, it worked fine. But I DID reduce the amount of thread on the bobbin at the same time as Drazil suggested.

SOURCE: Can't reassemble shuttle hook and shuttle race

the hook driver (still in machine) is 1/2 moon shape. The hook is also 1/2 moon shape. If you set the machine on its back, it's easier. Set the hook 1/2 into the other 1/2 of the hook driver to make a circle. Then put the hook cover on (machine still on its back) with the tabs for the twist locks pointed out. Needle gaurd to the top of the machine. Snap the twist locks in place and viola!
Kent

SOURCE: where is the shuttle race on a bernina artista

Just to the left of the bobbin case you will see a small lever. Remove the bobbin case and push the lever and that will release the latch which holds the race cover and shuttle (hook).

Clean well with a toothbrush and place one small drop of oil on the edge of the hook where it makes contact with the raceway. Place the hook back and snap the race cover back on.