dhahlen

Happened at the track, car had a used triple plate carbonetic. K24/18g, running 100 octane at 1.1bar.

Noticed a weird noise in the decel, sounded like it was choking.

-Oil pressure good
-Temps are normal
-No leaks
-Nothing odd in the oil filter
-No Smoke

Heard the noise, shut off the engine.

Couldn't start the car to move it on the tow truck.

Friends ended up pushing it, I dumped the clutch and it fired up, had to give it a bunch of gas to keep it running at first. Finally got it to idle, exhaust note sounded fine; however, engaging the clutch made a similar noise to what's in the video. Drove it up onto the tow trunk where it stalled.

I figure the pressure plate on the clutch exploded and something jammed up against the flywheel, preventing the starter from turning the flywheel.

Pulled codes I had P30x for engine misfires on 1,2,4,6

Last over-rev was an hour before max engine run time. Probably due to reflash and driving at the top of 2nd/3rd on the track.

If anyone is familiar with the sound, input would be appreciated. I did not hear any knocking or clanging, just this whirling sound.

Car is getting towed to EvoMS today for inspection.


Thanks!

dhahlen

Well, the problem is obvious. However, I am trying to figure out how this happened.

I don't have a picture of the bell housing, but it was sheared on the inside, but not enough to put any holes in it. I have a couple of theories, but I figured I'd get some other input from those who may have seen this before.

The starter is likely from me trying to start the car after it was locked up.

The clutch internals are fine, but obviously the flywheel is not. The starter may be salvageable, but I'll probably replace it.

Some questions:

-Is it possible for a bolt to back out of the assembly?
-If so, what would cause it to do so?
-The flywheel cannot make contact with the bell housing when it's attached to the input shaft, so what would cost the bell housing to get sheared and the teeth on the flywheel to grind down?

CincyScott

So what did happen? Did the starter gear back out? I'm lost...

dhahlen

Wouldn't explain why the bell housing is marred up.

Pictures are of the flywheel teeth and starter. The starter probably got marred from me trying to start it to get it on the tow truck.

I am trying to figure out how the flywheel got damaged, thus causing this whole fiasco.

Macster

The flywheel damage is one of the aftereffects of what went wrong.

My WAG is the starter spur gear failed to fully engage the ring gear on the flywheel and that is why the ring gear teeth are worn like they are.

That is unless you found something jammed in the bellhousing that could have done that.

But the starter spur gear teeth look like they've had a rough time of it so my money is on the starter spur gear not fully engaging the fw ring gear teeth.

A bench test (well, vise/bench test) of the starter may find the starter spur gear does not fully extend out or perhaps does not fully retract.

dhahlen

I tugged on it pretty good, retracts fine. It may act differently under operating conditions, heat, etc.

I am guessing something got jammed inside, it's the only thing that would explain the marring of the bell housing.

I had to push-start the car, basically dump the clutch in 1st to get it to move.

If something were in the bell housing, what would it have been? I am waiting to see if EvoMs found anything floating around in the bell housing AND if all the bolts are accounted for.

Macster

Damage inside the bell housing does suggest something loose that got jammed and causes the abrasion of the gear teeth.

Clutch disc rivets are generally soft so one of these is not likely. 'course if an inspection finds one missing....

If the clutch disc has cushioning springs one of these can have failed. But as with a rivet an inspection should find one of these missing and fragments in the housing.

Not much a flywheel could shed though a flywheel bolt failing (or just backing out) is a possibility.

There is not a lot of hardware inside the bell housing that can come loose so there are not too many possibilities.

Be aware the bell housing and the engine may be separated with the tech some distance away and he may not see something fall out of the bell housing when it is separated from the engine. His attention will be focused on getting the two items apart and not dumping the tray off the lift. Looking for stuff from the bell housing will not be a top priority for him.

And the item will of course fall out the bottom and it will not be that far to the floor (unless the tech removes the tranny with the engine still in the car) and will probably not make much noise and unless the tech looks for anything afterwards he'll not likely spot it the moment it falls out.

Then there is the condition of the floor under where the engine/bell housing are separated. Some shops you could lose a tranny in the mess...