Anyone else have their clutch blow up?

[samwyse]

This happened on my old 1986 2.9 4x4 manual 5 speed.

I parked in gear with the clutch full down and waiting for the truck to heat up. Suddenly the truck lurches forward and dies (I had my foot on the brake as well, luckily).

Not really being smart (still amn't) I tried to start the truck in neutral, as soon as the as the engine started I could hear rattling below me and shut if off quickly.


Later when my brother took apart the clutch, turns out the flywheel (not stock) had broken into four pieces! He said he had never seen a flywheel break, let alone in to multiple pieces.

 

[don4331]

Sam:

Obviously, neither you nor your brother has drag raced. There is a reason for the scatter shield over the clutch at the drags.* When they let go at 8k rpm+ they are a tad more violent than your case!

I'm actually surprised that the pressure plate/ring gear/etc held everything in place so you could restart it.

*Or a ballistic steel bell housing. Most associations don't allow cast flywheels just for this reason.

 

[gw33gp]

Old flywheels get fatigued just like any metal. You were lucky it happened at idle. I have never broken a flywheel but had the flywheels bolts shear on my SCCA road racing sports car one time. This was at about 7,500 rpm. I never felt such a bad vibration in my life. The trans input shaft kept everything in place and the clutch helped to keep the flywheel from getting to far off center. I popped it in neutral right away and got on the brakes not knowing what happed. The vibration broke the transmission tail shaft housing and dumped oil all over the track making for poor traction at the rear wheels. I managed to keep it under control and moved over to the edge of the track and rolled into the pits. Race over for me.

 

[samwyse]

Sam:

Obviously, neither you nor your brother has drag raced. There is a reason for the scatter shield over the clutch at the drags.* When they let go at 8k rpm+ they are a tad more violent than your case!

I'm actually surprised that the pressure plate/ring gear/etc held everything in place so you could restart it.

*Or a ballistic steel bell housing. Most associations don't allow cast flywheels just for this reason.

Haha clearly we haven't. I mean, it was just a 2.9 litre. Not exactly a rubber melter.

 

[AllanD]

In my life I've has several explosive failures of clutch discs...

One on my ranger with a Luk Performance clutch for a 4.0, it failed somewhere over 5000rpm... somewhere I shouldn't have taken it (entirely my fault)

Another was behind a 225 slant6 dodge engine of all things I was downshifting from 4th to 3rd but got 1st instead (sloppy shifter) and spun the poor little thing right off it's own hub, sounded like an exploding glass soda bottle

The most violent clutch blow-up was when I had a pressure plate inertia ring fail
on a 340-4bbl Dart I was test driving (I was buying it for parts) and it destroyed the bell housing and several large pieces came through the floor and trans tunnel and tore the sole off the sneaker on my right foot... (I bought the car anyway, conviently I had a two truck waiting to tow it home) pieces flywheel were everywhere...

The cars owner admitted the flywheel was a junkyard part off a 318 (cast iron
and not rated for the near 7000 rpm I spun it to before failure...

Fotunately, It didn't damage the block but the bellhousing was utterly destroyed..
(I had spares)

the last one I popped an AP-Lockheed racing clutch in my Saab Turbo, that one was a disc failure but only destroyed the plastic clutch housing cover.

AD