I have a bike with a rear wheel with an M675 disc hub arriving imminently.
I want to put that wheel on another bike, with a 142x12mm back end.
Shimano make the M678 SLX hub, which to all intents and purposes, looks the same as the M675 rear hub but with a 142x12 compatibility.
My question is, can I buy the M678 hub, take it apart, take the M675 hub apart, and swap axles over? Or have I got to take the wheel apart and rebuild with a different hub (which will obviously be much more long winded)?
Without knowing the exact combination, most Shimano hubs are not compatible. I was unable to use an XT front hub that started life as q/r with 15mm axle even though there was a 15 mm option available in the same group set.
You could be lucky though!
Worth a try - I know it's completely different, but I have currently got a 2012 XT freehub bodged to a 1994 STX SE hub body (to get 9 speed cassette on it - as it came with a 7 speed freehub) - it works well and didn't need too much modification - both were QR type hubs but I would give it a go if I were you!
shimano techdocs should provide the answer no problem with exploded diagrams.
[url= http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/FH/EV-FH-M675-3402A_v1_m56577569830805676.pdf ]FH-M675 Diagram[/url]
[url= http://techdocs.shimano.com/media/techdocs/content/cycle/EV/bikecomponents/FH/EV-FH-M678-3403_v1_m56577569830800246.pdf ]FH-M678 Diagram[/url]
The two hubs had different freehub bodies. I assume this is because you can't fit the larger axle through the normal body.