My ACT Clutch failure

[bNasty]

Alright guys i just wanted to share with everyone my failed ACT clutch. It seems that for whatever reason the teeth on the clutch disk where the input shaft goes has completely sheared off. I dont know why or how this happened. Ive only had the clutch for 1500 miles. I drove the car very easy in this time as i was breaking in my motor. The splines on the input shaft itself seem to be fine and completely undamaged. It is weird because the teeth sheared off all at once. I was at a stop sign near my house, i shifted into first let off the clutch a bit then BOOM no gears and it made this terrible grinding noise.
enough words here are some pics

Heres a normal ACT street disc that i have laying around just for reference

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And heres my ACT 4 puck unsprung

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[BigBeans]

It would be worth showing this to ACT.

Any launches or hard use at all? Even if so this shouldn't have happened, but i'm just curious.

 

[bNasty]

It would be worth showing this to ACT.

Any launches or hard use at all? Even if so this shouldn't have happened, but i'm just curious.

none at all i was breaking in my motor. I drove the car real easy it only really saw highway driving to and from school.

 

[donniekak]

That is how unsprung hubs fail, usually not that fast. Your input shat is probably also ruined. If there is any play at all between the shaft, and hub splines, it's only a matter of time before this happens again. For the record i've seen a few of the act unsprung disks fail in this manner. The unsprung xtd disks can also do this, but usually make a knocking sound for a while before failure. Their hub material is also a good deal softer than the input shaft, and doesn't ruin the input shaft upon failure.

 

[bNasty]

That is how unsprung hubs fail, usually not that fast. Your input shat is probably also ruined. If there is any play at all between the shaft, and hub splines, it's only a matter of time before this happens again. For the record i've seen a few of the act unsprung disks fail in this manner. The unsprung xtd disks can also do this, but usually make a knocking sound for a while before failure. Their hub material is also a good deal softer than the input shaft, and doesn't ruin the input shaft upon failure.

so you think my input shaft is ruined? I mean i put the street disk on it and it still seemed to fit fine there really wasnt any play. Thats the first thing i checked was the input shaft.

 

[ACTman]

Torsional vibration is what normally wears disc splines, not torque or abuse. These torsional vibrations are quite severe on four cylinder turbo vehicles. Since the disc center is solid, the torsional vibrations are basically acting like an impact hammer directly on the splines of the disc. The splines will not last as long as a spring center disc.

But what you are experiencing is not normal since the splines should last thousands of miles, not hundreds. There is not much that can cause the disc splines to fail as prematurely as you indicated. Here is what comes to mind:

1. Misalignment of the engine to transmission, such as if one or both engine dowels are missing. Check to see if both engine dowels are in place. Missing dowels have become so common on the DSM, ACT now supplies new dowels with every DSM clutch kit. Loose or missing engine bolts can also cause misalignment.
2. Severe torsional vibration (not likely). An improper tuning problem can cause excessive torsional vibration. Torsional vibration also increases with hot cams, increased boost, a lightened flywheel, etc.
3. Inferior disc materials. That is not the case with the ACT disc. There are some disc hubs that are made of very soft materials or have a very short spline area. The ACT solid hub discs are chrome-moly steel and half-hard (RC 25-35) so they are designed to wear reasonable slow without taking out the input shaft splines. If they were made harder, the input shaft would wear out instead of the disc splines. Being a race part, they are not intended for daily driving but many people still use them this way.
4. A worn input shaft prior to clutch installation. Bad input shaft splines will cause bad disc splines. It sounds like you checked this out but since we are on the subject, it's worth mentioning to other readers.

Whatever the cause, the good news is that ACT can repair the disc at a fraction of the cost of a new part.

 

[phunny]

Torsional vibration is what normally wears disc splines, not torque or abuse. These torsional vibrations are quite severe on four cylinder turbo vehicles. Since the disc center is solid, the torsional vibrations are basically acting like an impact hammer directly on the splines of the disc. The splines will not last as long as a spring center disc.

But what you are experiencing is not normal since the splines should last thousands of miles, not hundreds. There is not much that can cause the disc splines to fail as prematurely as you indicated. Here is what comes to mind:

1. Misalignment of the engine to transmission, such as if one or both engine dowels are missing. Check to see if both engine dowels are in place. Missing dowels have become so common on the DSM, ACT now supplies new dowels with every DSM clutch kit. Loose or missing engine bolts can also cause misalignment.
2. Severe torsional vibration (not likely). An improper tuning problem can cause excessive torsional vibration. Torsional vibration also increases with hot cams, increased boost, a lightened flywheel, etc.
3. Inferior disc materials. That is not the case with the ACT disc. There are some disc hubs that are made of very soft materials or have a very short spline area. The ACT solid hub discs are chrome-moly steel and half-hard (RC 25-35) so they are designed to wear reasonable slow without taking out the input shaft splines. If they were made harder, the input shaft would wear out instead of the disc splines. Being a race part, they are not intended for daily driving but many people still use them this way.
4. A worn input shaft prior to clutch installation. Bad input shaft splines will cause bad disc splines. It sounds like you checked this out but since we are on the subject, it's worth mentioning to other readers.

Whatever the cause, the good news is that ACT can repair the disc at a fraction of the cost of a new part.

He said the input shaft is fine. If the dial pins were not present and there was that much movement the input shaft would no doubt be damaged. This looks like the part failed for some reason and the vehicle did not cause it. Even if the car was beat on this shouldn't have happened. As far as letting ACT repair it... No thanks. Their part failed and they want you to fork out money to repair it...ha

If you look at the OP's upgrades you'll see he hasn't cut any corners and surely didn't bolt the tranny to the block "without dial pins " to let his new motor tear itself up.

I know I've been away for a year or two but if I recall correctly there were MANY threads about ACT clutches failing left and right.

 

[bNasty]

He said the input shaft is fine. If the dial pins were not present and there was that much movement the input shaft would no doubt be damaged. This looks like the part failed for some reason and the vehicle did not cause it. Even if the car was beat on this shouldn't have happened. As far as letting ACT repair it... No thanks. Their part failed and they want you to fork out money to repair it...ha

If you look at the OP's upgrades you'll see he hasn't cut any corners and surely didn't bolt the tranny to the block "without dial pins " to let his new motor tear itself up.

I know I've been away for a year or two but if I recall correctly there were MANY threads about ACT clutches failing left and right.

This is correct. I have not cut any corners with this build. The dowel* pins are in place on my block. I dont know how a clutch can become "misaligned" anyway, since it needs to fit on the input shaft. I talked to someone at ACT and while being very helpful still said that the best ACT could do was rehub the disk for a small fee. I do not really want to use another ACT product again. But i do not understand why ACT cant just send me a new disk, this is obvious that the failure was not a cause of the car but of the disk itself. The person further more questioned why I had purchased their disk in the first place. Because this disk is "not recommended" for anything but a full race application, I drove the disk fine and really had no issues with it, I thought it was easier to drive than my Fidanza 3.2. While i understand that its not meant to be daily driven and thats fine, the fact of the matter is that the disk failed and really ACT isnt doing anything to help me replace it.

Since this I have gone ahead and ordered a South Bend SSX from TMZ performance with the TZ/FE disc. I will let everyone know how this goes. Im really excited to get this new clutch in