I don't know too much about these newfangled M3Ws but on the middle-aged ones with 3-speed & reverse gearboxes, which were positioned exactly where the five-speeders have their bevel box, we were discouraged from covering them with sound-proofing material (usually bits of carpet or felt underlay in those days) due to it impeding the cooling air flow over the casing and thus causing overheating which had disastrous effects on the worm and worm-wheel.
Do the new bevel boxes get hot? If so, it might be worth ensuring they are given every chance to keep as cool as possible by keeping Dynamat a reasonable distance away and maintaining good air flow over the box.
Chris J
