Just fixed a few days ago, my Z1 clutch/flywheel kit that I purchased ~10,000 miles ago had an issue when I was having my CMC replaced (issue was masked by CMC going out).
After the CMC replacement they couldn't get more than half the clutch back even after extensive bleeding. They had to remove the transmission and found that 4 of the pressure plate bolts BACKED OUT!
I go to a VERY respected transmission shop in Oregon (
Columbia Transmission Co. | Serving Portland for for over 45 years) this place has solid reviews on angies list and their service is very akin to Fast Intentions.
They had to loctite and re-torque the bolts which makes me wonder if the material of the bolts are proper for this application. Thankfully they didn't charge me for the trans pull as they were the ones that installed the clutch.
I'm not 100% if the issue is bolt material but knowing who works on my car does make me lean in that direction.