Quote:Theoreticly, if you had a single disc brake at the back of the trans, then it would be part of the sprung mass, but to be effective, you would need a spool because with a regular diff, you could lock up the driveshaft with the brake, then have one wheel in the mud at the side of the road with the other on the good stuff & find one wheel rolling forward, while the one on the slippery stuff is actually rotating backwards.
The net effect is no rear brakes at all. The spool would prevent this, but it increases tyre wear & makes it hard to park in shopping malls.