Why do reverb tanks die?

[g1]

The magnet, wire, and hook are all one piece. About the only place you can get them is from other broken tanks. Then you have to consider that there is foam damping material in the tube the wire goes into. And there are north and south poles of the magnet that really should be set to proper orientation.
Lots of work to get it right.
Long ago, Fender used to sell the whole transducer assembly, which was the plastic piece with the coil and the 2 magnet/tube pieces. That is really the best way to repair a tank.

[Mick Bailey]

I've relocated the suspension complete with magnet from donor tanks quite a few times, but it can be tricky to get the de-soldered end through the hole in the foam. I've also made a new suspension wire from a guitar string and transferred the magnet and stuck it in place with a tiny bead of epoxy. Getting the magnet off the donor tank requires soaking it in MEK overnight and sometimes warming the wire with a soldering iron just enough to slide off the magnet without destroying the magnetism.