My car is one of the rare factory 5 speed (m56h internal slave) V70 T5's, currently with 152,000 miles on the clock. About 44,000 miles ago, at 108,000 miles, I replaced the original clutch and dual mass flywheel with an 850R clutch/pressure plate and single mass flywheel. The "new" clutch is now slipping again with just over 40k miles on it.
Also, the m56h gearbox has an annoying problem. Although it shifts very well in every gear, it has "slack". For example, if you get under the car and grab an axle and turn it, it will twist or rotate back and forth slightly even though the transmission is in gear. I've been told the term is "gear lash". When driving the car, this results in rebounding or "bouncing" with each shift release. I believe the early clutch wear was in part caused by my efforts to finesse the clutch release to avoid this bounce effect, but also by the increased power/torque from lately using e85, which I plan to continue. So I am looking for a replacement m56h to install with the new clutch/pp.
My primary question is what model/years should I be looking for to find an m56h with an internal slave that will bolt up with no or little modifications?
I am currently leaning toward another 850R clutch setup, but 'm also interested in suggestions for a mildly upgraded clutch/pp setup for this, my daily driver, that might better hold up to the engine's output.
Finally, the current single-mass flywheel has been resurfaced one time. Is there any reason to believe this flywheel won't be amenable to an additional resurfacing?
[Originally posted in maintenance forum; but since manual-transmission swaps are commonly viewed as a performance modification, I re-posted the thread here.]