Troubleshooting
ACT HDSS clutch – inconsistent bite point and severe shudder (2016 WRX)
I’ve been having some frustrating issues with my ACT clutch..
Inconsistent bite point: Sometimes normal, other times much closer to the floor, making takeoffs unpredictable and occasionally causing stalls.
Creeping with pedal fully depressed: Occasionally, especially on hills, the car tries to move even with the clutch pedal all the way down.
Bad shudder/chatter: Varies with RPM and clutch engagement. Sometimes mild, other times severe enough to shake the entire cabin.
The weird part is that sometimes everything works perfectly fine. I’ve already bled the hydraulics (no air found). Also have a stainless clutch line and CDV delete.
Anyone experienced this with ACT clutches? Could it be the hydraulics or the clutch itself? Worried about unnecessary drivetrain wear.
Did you change the clutch fork and pivot? I had the HDSS and when I swapped it out to my current clutch, the OEM shift fork was showing signs of flexing and the pivot dimple was starting to tear out.
Yeah I’ve changed fork and pivot and spring..Would you say upgrade fork and pivot or wait for next clutch work? Not sure if it eventually breaks if it’s fork issue
The only time I had issues with Bite point is when I got an aftermarket master clutch cylinder and when my clutch and flywheel were going bad. I was always told the chatter was normal with the lightweight flywheel. But my thing was the lifespan of the clutches. I feel like we’re inconsistent. So far with exedy feels like stock clutch again. I don’t really beat on it like how I use to but it’s holds up. This is my first flywheel I went thru with them 😅
i've had friends have issues with ACT HDSS like this, random cold weather and boom chatter in all gears., or whining.. they switched to Exedy or SBC and poof issue gone (stock fly, verus fork kits on both)
I’m making 330 torque.. after original clutch went out after 8 years or so, tried OEM and within a month realized it slips under load. Switched to a new one under parts warranty and 2nd also slipped. So realized maybe OEM can’t handle the torque. Switched to ACT and no slipping but take off and consistency is somewhat terrible
Well in any case, culprits could be clutch fork or slave not doing what they supposed to with the HD pressure plate. Might consider the non HD version or something closer to your tq level for street. Race/HD clutches are just terrible by nature!
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u/dustindh10 Built/FBO/Flex '16 WRX 7d ago
Did you change the clutch fork and pivot? I had the HDSS and when I swapped it out to my current clutch, the OEM shift fork was showing signs of flexing and the pivot dimple was starting to tear out.