So the mounts of both sides break? Surely something else is going on.

When replacing the mounts, have you replaced the tranny mount?

The three mounts form the total support of the engine+tranny unit. It is the tranny mounts that keeps the whole thing from moving to the rear, and it is that rearward movement that breaks the motor mounts.

The mounts get weakened from having oil on the rubber. I always cover the right side motor mount when removing the oil filter, but there's not much to protect the tranny mount.

Do all three, tranny last, and see how that works.

Good Luck,

Bob

:>)