My South Bend CLutch failure (Pics inside)

[bNasty]

So if some of you have been following my build or friends with me on FB you will see that I was dynoed last week and you will have also seen that my SBC clutch took a dump. The hub basically broke and 1 spring popped out and 1 spring broke in half. This occurred after a 400+ hp dyno pull.

My question really is. What causes the springs to come out like this. And after my ACT clutch failure two months ago (stripped splines in hub of clutch) I had the shaft checked and everything was ok. Im just curious why I keep having clutch problems like this.

Now for the pics

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[nuclearr]

Why not go with an unsprung disk? I have been DDinng a 6puck unsprung for several months now.

 

[bNasty]

Why not go with an unsprung disk? I have been DDinng a 6puck unsprung for several months now.

well my last clutch was a 4 puck unsprung and the splines stripped out of the hub in that clutch

 

[PieEyedPiper]

Did this occur during the pull or when a shift was made?

 

[agentorange313]

Did this occur during the pull or when a shift was made?

I would like to know this also. I am a long time user of South Bend Clutches.

What pressure plate are you using from southbend?

 

[DECODER22]

wow never seen one break like that i have installed a lot of SBC kits never had any issues

 

[e85_4g63]

I had the EXACT same issue, with SBC's kevlar disc. Even Tim Zimmer (twicks69 on here) spoke highly of that particular disc. Springs broke out on mine (16g @ 14psi). Not sure what's up...

 

[hypergenesis]

They could just be defective ones? Part of a bad batch or something it does happen

 

[96awd]

I sent this thread in a PM for Tim to chime in.

I'm kind of skeptical about using SBC now. May just go for a Twin-Disk and call it a day now.

 

[twicks69]

Probably a bad batch or the result of a prior mis-shift, or during installation the transmission was putting weight on the clutch disk hub and you bent the hub.

The failure rate on SBC's clutches are crazy low in comparison with their competitors.

The SSX clutch setups use the better EXEDY racing disk hub that has the springs and isolator bushings.


Who is BNasty? Is this one of my customers? Either way, contact SBC or the vendor you purchased from and get it replaced under warranty.

 

[95eclipser]

The pull was made on a Dyno Dynamics Dyno at PTUNING.

The failure of the clutch was noticed after a pull was completed (20psi about 389hp). The tuner had turned off the car to flash over the new changes to the map. Once this was complete we pushed in the clutch to start the car, and the tuner noticed the intense force needed to push it in.

Are first thought was a clutch spring had popped lose. I was a lil surprised as the clutch had made about 9 good pulls before the incident occurred. i have seen CM clutches do this, but this is my first SSX iv seen.

hope this helped give a lil better back ground.

P.S. I was the one who checked the car in, and drove it around back. The clutch engaged completely fine and had very smooth transition through the gears.

Drew

 

[dsm8883]

We are having the same issue in our gst and it ended up being the trans shifting on the block causing a alignment issue under high rpm and torque... bad and worn bolt holes and alignment pens. Broke 2 act disc and stripped 1 out

 

[Chrispy0530]

(stripped splines in hub of clutch)

Not trying to thread jack, but why/what causes this to happen? I remember this happened when I was running my Excedy Twin Clutch. Was a shame too cause it had so much meat left. Excedy no longer makes the Twin for DSM's anymore.

 

[donniekak]

Not trying to thread jack, but why/what causes this to happen? I remember this happened when I was running my Excedy Twin Clutch. Was a shame too cause it had so much meat left. Excedy no longer makes the Twin for DSM's anymore.

This seems to be the failure point of all the unsprung disks. You can usually hear them rattle at idle before they fail completely.

 

[BigBeans]

Bnasty,

It seems like there's something off with the car or your installation techniques. This is the second clutch hub to fail in what, a few thousand miles? Both clutches were reputable brands and quality parts, so something isn't adding up.

 

[bNasty]

Bnasty,

It seems like there's something off with the car or your installation techniques. This is the second clutch hub to fail in what, a few thousand miles? Both clutches were reputable brands and quality parts, so something isn't adding up.

I agree I feel like something is off but I dont know what I mean this isnt like my first install either. On my GST I installed the clutch and had no issues for over 20k miles. Im really puzzled all my alignment pins are in correctly and everything.

Probably a bad batch or the result of a prior mis-shift, or during installation the transmission was putting weight on the clutch disk hub and you bent the hub.

The failure rate on SBC's clutches are crazy low in comparison with their competitors.

The SSX clutch setups use the better EXEDY racing disk hub that has the springs and isolator bushings.


Who is BNasty? Is this one of my customers? Either way, contact SBC or the vendor you purchased from and get it replaced under warranty.

I am one of your customers I sent you these same pics in my email to you yesterday and Ive been in contact with you over the phone. (TMZ performance correct?)

 

[twicks69]

Gotcha. Ben. Yup, that's me!

I just like keeping track of user names with real names.

We'll take care of this dude, no problems. As for turnaround, it should go fairly fast. I will likely have you talk directly to Jon at SBC before shipping it out. We'll talk Monday morning.

Tim Zimmer via Evo Phone