Went to Lebanon Valley for their first index race. Ran 10.0 class and stumbled my way to the final (light turnout). Launched great, when I shifted to 3rd...bang


Was having trouble launching on the 2 step. I finally realized in the semi final, it was not working, so I was launching on the upper rev limiter (7200 instead of 4400)...Hard of hearing

The splined hub remained on the input shaft, sheared all of the rivets. You will note that there is no section of the disc missing, the slots just closed up

I haven't found any other damage yet.

Wow that is crazy

That's not good. It would be nice to know whose disc it is. Maybe they had a bad run or something.

That's the last thing I need to happen.

It is a McLeod. But I'm pretty sure that they are all made by the same company. I looked back at old discs and they all have cracks starting, The cracks start at the keyhole at the slots and then start migrating. I started bevelling the holes to see if it would help. I guess not. But this was a well abused disc. The 7000 rpm launch didn't help

Glad you are ok.
Steve

That could have been real ugly.

I have had that happen, sheared the rivets right off. I just replaces the disc thinking everything was good. After assembly I found there was a vibration that I couldn't find. Finally pulled the clutch assembly back out and noticed the pressure plate clamping face was off center. Looking at the pressure plate I found that one of the 3 torque bars was bent, pulling the plate off center. These are the multi stacked plates that are riveted to the top cover plate holding everything together. Doing research with the clutch manufacturer they stated the shearing of the rivets released the torque on the system causing the bar to bend. I don't know if thats what caused my problem but replacing the pressure plate solved the vibration .

I'm glad that failure did not hurt you or the car
I quit running a 4 speed car back in the mid 1970s due to the high maintenance I learned early on racing that car I had to feed the stick shift cars parts, clutches, tires, U joints or some other expendable parts
Now my stupid S/P car thinks it needs maintenance also

One thing about racing a stick shift car you find the weakest link over and over till you get it right. Haven't broke a u-joint in years but I broke the dana 60 twice.

ouch! glad you and the car are ok!

Yikes! !!

That could have gone bad quickly.
I imagine the whole driveline took a beating.

Whow, that sux...I'm glad you and the car are okay though. Parts can be replaced.. C U soon.

Damn. Glad you're alright. Did it beat up the bellhousing bad?

I thought Ram told me once that I think it was Boninfante makes all the sintered frictions.

There was no other damage. The disc just started to touch the PP hat, but is ok. It's lucky that the hub let loose when it did, and the section of disc did not let loose.

The moral of the story is: look at the disc closely from time to time. I think.

New disc coming! Hope to be back at it soon. Will cu in not too long.

Dang, that could have been ugly. When I first built my Duster I built it as a four speed. It never made a full pass with the stick in it despite spending about 4 times as much money on it as a really nice auto and converter would have cost. Put the 904 in it and except for converter hubs cracking I never had another driveline failure.

I had a older Dodge 1.5 ton car hauler that the rivets in the 12 inch clutch disc hub failed on a upshift letting that old tire flathead six rev way up, it worked and then it didn't
Parts fail

I would also say you need to buy a lottery ticket, glad to see it all stayed together enough to keep from picking up chunks off the track.