Author Topic: Pilot shaft question  (Read 2836 times)

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Offline Clay Pitkin

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Pilot shaft question
« on: November 27, 2014, 10:38:47 PM »
Question:

Ok so I have a question:

On my FWD (Front wheel drive) on my adapter pulley, it used to have a Allan head bolt in the center of the pulley that you would tighten down on the crank, then the flywheel bolted to the pulley.

I replaced the Allan head bolt, with a normal bolt. Because of the normal bolt, the pilot shaft would not clear. So I called and spoke with a transmission shop, and they told me that I could shave the pilot shaft as long as I did not go into the splines of the input shaft. I did this and the input shaft no longer goes into the pilot shaft bearing.

Will this be detrimental to the operation of the clutch, pilot bearing etc?

TIA
Clay
Those who said it could not be done, should not stand in the way of those who are already doing it!

Offline Peter Jack

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Re: Pilot shaft question
« Reply #1 on: November 28, 2014, 12:39:23 AM »
It'll likely shake itself to dangerous destruction as the clutch disc goes off center.

Pete

Offline Stainless1

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Re: Pilot shaft question
« Reply #2 on: November 29, 2014, 12:19:21 AM »
The input shaft needs to be supported on both ends.... the spinning clutch will take out the trans bearing on its way through the bell housing...
Stainless
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Offline kiwi belly tank

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Re: Pilot shaft question
« Reply #3 on: November 29, 2014, 12:43:06 AM »
Ok, so you did this on the advice of a trans shop who obviously asked what you were working on & were likely familiar with what you have & now you expect some advice here when you offer no details. :?
Some FWD input shafts are so short that with a double row main bearing & the main shaft pilot bearing this would not be an issue.
This does not mean you are ok, your question is just too generic.
  Sid.

Offline fordboy628

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Re: Pilot shaft question
« Reply #4 on: November 29, 2014, 05:57:24 AM »
Well,  whoever designed the setup you are using thought the pilot shaft needed to be located/supported at both ends . . . .

If, as PJ suggests, the shaft can now go "off center" during high rpm operation, only bad things are going to happen.

One last thing to consider:
Where are your feet/legs in relationship to a clutch explosion?

My experience is that high rpm shafts (anything over 1500 rpm) need to be restrained in their correct position.   The consequences of not doing so can be pretty dramatic and injurious.

JMO
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Offline Clay Pitkin

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Re: Pilot shaft question
« Reply #5 on: November 30, 2014, 02:47:49 PM »
Ok so here is what happened.

I have an adapter pulley, that bolts on the end of my crankshaft using an Alan head bolt. Well the Alan head bolt, was chewed up and so we decided to use a normal bolt.

In doing this, we found marks on the head of the bolt from the pilot shaft indicating that it was to long/close. As a result of this the gears in the trans were toast.

So, I sent the trans off to California, a good friend of mine put all new gears in it, good to go.

But, I still had an issue. The clearance on the bolt/input shaft.

So I called a reputable trans shop here in Utah, asking if I could cut the input shaft to clear the bolt. The guy said, yes, in-fact you can cut it all the way to the splines, so that's what I did.

Now upon further research, this was not a good solution. I called the shop back, and looked at the replies on here and yes the trans would work, the clutch just would not work for a long period of time and bad things could happen.
So my bad for not asking more questions before acting.

So yesterday took engine/trans back out of car, now, the trans is heading back to California for new input shaft.

So my question was does the Pilot shaft have to be in the pilot shaft bearing to function properly?

Indeed, yes it does.

Lesson learned!

TIA
Clay






   
Those who said it could not be done, should not stand in the way of those who are already doing it!

Offline Peter Jack

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Re: Pilot shaft question
« Reply #6 on: November 30, 2014, 02:55:27 PM »
Clay, when you're looking for answers you can never supply too much information. Photos and a thorough description of your issues can usually result in more than one solution that will work but your brain stormers need as much information as possible.

Good luck with your solution.  :-D :-D :-D

Pete

Offline jdincau

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Re: Pilot shaft question
« Reply #7 on: November 30, 2014, 05:59:44 PM »
Well the Alan head bolt, was chewed up and so we decided to use a normal bolt.    

That was the lesson
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