When i really get on the gas and into higher RPMs, I notice my clutch pedal becomes soft and actually goes to the floor?? It does NOT start to slip at all, in fact, all 4 tires were spinning through third pretty good... . After you let off, the clutch pedal does come back and work normally. Ive had this happen throughout the summer. It has a twin disc in a dogbox tranny. Im convinced it's the dogbox doing it, but I have no idea.
Anyone with ANY info, would be appreciated, thanks.

Kyle, I'm presuming you have checked the hydraulics. If they are ok, I'd start by checking the crank end play.

It's hard to fathom an engine with that much end play. Even the worst case of walk I've seen only has a fraction of the amount of mechanical movement in a clutch.

Nothing's impossible though.

Hydraulics doesn't make sense, because if it only happens at certain rpm, it can't be related

Reza's end play comment falls in line, but not to the point where u say the pedal can go to the floor with no disengagement.

Kind of bizarre

I had a completely stock 1g over 10 years ago with severe crank walk that the clutch pedal would fall to the ground on left turns. The worst amount of end play I have seen was on Mike Degli's 1g when my brother owned it. From the clutch pedal falling to the ground on left hand turns, it turned into a severe vibration as the crank was digging into the mains. It still ran though.

A twin disk only requires such a small amount of throw to disengage. With crank end play out of spec, the clutch won't slip at all. Instead of full disengagement you just move it over when you go to step on the clutch. Now with a dog box and a twin disk, it'll probably still shift like a champ but just make your clutch pedal go to the floor like what Kyle is describing.

Of course it could be something else, but being a DSM I'd consider the worst case scenario first.

If it is out of spec, but not enough to score the thrust surface, I'd drop the pan, toss in a new thrust bearing and align it proper. Been there, done that already

I hope that is not the case though Kyle and it's something weird like a bad master or clutch. Checking the crank end play is just too easy to start with. Might as well rule that our first.

Amazing that it can walk so bad the clutch won't dissengage!

That blows my mind

So for kyles issue, I'm assuming the nature of his particular rotating assembly is causing the crank to shift to one side at higher rpm's, causing the lack of throw needed to dissengage? Is the fork different in the twin setup? I'd imagine the same amount of throw is applied if not

Fork is the same, it just does not require a super full engagement like any other single disk setup. In other words if you went from a single disk ACT2600 setup to a twin disk without turning down the clutch pedal so you don't have maximum throw, you will damage the pressure plate, i.e. over extend the fingers.

That is one of the things I love about a twin disk setup. Your clutch pedal doesn't need to be cranked all the way out in order for it to disengege. With a single disk heavy ACT setup which requires you to put your foot through the floor board, a little bit of crank end play will cause it not to disengage at all. Throw in an OEM clutch setup and it will probably disengage where the ACT won't. Every clutch is different.

I have a feeling Kyle doesn't like this discussion anymore, lol.

Ha ya sorry Kyle, just check the horrizontal gonkulator, that's probably it

Sorry one more thing i don't compute

If a twin needs LESS throw to dissengage, wouldn't the walk have to be super bad if this was indeed the issue?

Kyle, is the spyder a six bolt? 7 bolt? Using a crank sensor?

Well he doesn't mention any clutch disengagement issues, or if he has tried adjusting the clutch pedal out to compensate for it. I get your point though.

All else the same with no adjustment done to the master, the clutch will slowly start falling to the ground as he describes.

It has nothing to do with the tranny. The clutch is bolted to the engine, not the transmission.

This is a built 6 bolt 2.4 galant bottom end, i dont believe its running a crank sensor. The clutch works fine and goes right back to normal after a pull. I dont use the clutch after im rolling but my foot's always touching it waiting, so i notice it right away.

At the top of a pull, and u push the clutch in to the floor, does it dissengage?

at the top of a pull, there is no pressure in the pedal to push, its already basically on the floor.

then when you let off and rpms start coming down the pedal comes back and clutch becomes perfect again

Is the transmission bolted to the block? Not kidding, heard of this happening. Not at the top of a pull, but still.

That happend to me once on my daily talon, the tranny bolts vibrated loose, but that gave symptoms more like a bad slave. Hard getting into gear, this is different.

Makes sense as then the throw would be increased as the tranny is pulling from the block. Id have a look into that at least. It also falls in line with the centrifugal forces at hand separating things at higher RPM

Don't worry guys, I've got this one.
WITCHCRAFT!

Sorry, that's all I can contribute to this. I'm having a really hard time wrapping my head around this.
Unless your clutch is heating up and expanding, thus forcing the pressure plate up and causing the peddle to go to the floor, I'm out of ideas. Also, doubt that would be the case in that short period of time.... Either way, just a thought....

I'm having a hard time trying to understand what your idea is.

Yea that's definitely not the case

Yea don't worry about it. Sorry, the clutch would have to slip significantly and expand quite a bit which I'm sure wouldn't happen.
Just thinking out loud.

No point in trying to guess this anymore. Kyle, do you know how to check for endplay, or to even visually see if the crank is moving a lot?

Nope, but ill start reading on it. Id assume it would start with dropping the tranny

No, you need a dial indicator, and a mag base.

Drop the t-case, down pipe, and oil pan. Then use a pry bar to push the crank all the way towards the tranny. Put the dial indicator on the crank pulley, set the dial to zero. Then pry the crank all the way to the pulley side, record your reading.

While your in there check the bottom of the pan for bearing.

Sorry Rob. But could he just leave everything together and put the dail indicator on the end of his harmonic. I know it is probably not as much a true test but for quick reference it should work. The spec is 0.002" anymore then that then maybe dive deeper by pulling the tcase downpipe and oil pan

.008 is the max, .002 is the min, it should even be fine up to .01 without any ill effect of usage until a rebuild is possible.

You could just pry on the pulley, but theres no way to tell your all the way to one side without doing it from inside the pan. The only thing to pry against is the belt cover, and thats not gonna get you an accurate reading.

EDIT, I guess you could step on the clutch a few times, then set the indicator to zero, then bash the balancer in to make it go opposite direction. But then you risk moving the indicator which wont give you a good reading.

Id take the pan off just to check for flakes anyways. I say do it proper, and KNOW your good.

Yeah your probably right. I usually pry on the crank thru the inspection cover.

Dropping the pan is probably best.

Inspection cover, never thought of that, thanks for the tip

Jack the car up and hook up a dial indicator on the crank pulley. Pry the crank over to the passenger side. Step on the clutch and measure the movement. I wouldn't even hook up the dial indicator and just eyeball it first. If you see it move a few mm's, you know its gone for sure. 5-10 minute deal, done.

If you want to drop the pan, no need for a dial indicator. Pry crank over to one side with a prybar between the crank and inside the block. Pry back to the other side and use a feeler gauge between the crank thrust surface and bearing. Takes 2 seconds and gives an accurate reading.

Here's a tip: When aligning a brand new thrust bearing on a new crank, if your on the low side like 0.002 , it's off and will start walking. High side of the spec means you got it aligned right

If u build a split thrust there's no need for any of that nonsense

but not everyone runs a split thrust motor which can still walk like any other....

I was referring to the alignment process

When I changed the oil before my last drive there was no flakes on the magnetic drain plug but there was a metal dust, like from break in.
I talked to the builder and he has no idea but doesn't think its crank walk. He's leaning towards clutch.

I makes sense to be crank walk, ill lose my tree if it is. Already kinda am.

How do I pry it over to the passenger side with the oil pan on?

Push on the harmonic.

If I move my crank by pushing with my hands ill cry

I'll cry with you man. She is so beautiful it would be a shame to have fix her up already.

Did you Find anything?

Havent looked at it yet

I've seen one block with enough play that you could just grab the harmonic balancer and push and pull it both ways, no need to even pull off the inspection plate in that case.