My Twin tub frigidaire washing machine FWLT1131FDH NOT SPINNING

SOURCE: WASHING MACHINE

Yes it agitates, but not spin

SOURCE: Frigidaire GLWS1339CS Top Loader, Won't Spin

Smoke usually means a major overheating of a belt or agitator transmission, get this checked before trying to run it again,

SOURCE: How to remove front panel of washing machine

there are two screws at bottom. unscrew. then lift up and out.

SOURCE: Front loader will not spin

The problem is the door latch assembly. You can get it at your local parts supplier or oder it through repairclinic.com. Should cost $50-$55. My hubby is replacing mine now. Not an easy part to replace, but by all information I have gathered from the manufacturer and the parts department, this is a common problem and most likely the cause of the machine not spinning. It runs through all the rest of the cycles, but will not spin, even on spin only cycle. The good news... if you replace the door latch assembly once, the replacement part is much stronger than the original and shouldn't have to be replaced again.

SOURCE: Frigidaire was tub makes loud thump noise during spin cycle....

Need more information to make an accurate diagnosis, try removing the front panel (two screws at bottom) and visually check first the belt (all the way around) and then the springs that hold the tub suspended.
I would bet on the belt.
Quentin