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F23 HTOB Overextending by CorvetteFan86
Started on: 07-08-2018 07:19 PM
Replies: 6 (463 views)
Last post by: fieroguru on 07-14-2018 02:54 PM
CorvetteFan86
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Report this Post07-08-2018 07:19 PM Click Here to See the Profile for CorvetteFan86Click Here to visit CorvetteFan86's HomePageSend a Private Message to CorvetteFan86Edit/Delete MessageReply w/QuoteDirect Link to This Post
Fiero Friends,

My father and I are working on getting my F23 swap completed in my Fiero. It has the 2002 Cavalier 60* bellhousing and a 2009 Cobalt 3.63 FY1 code gearing. I also have the L67 motor. Could you please review the HTOB numbers below and confirm if they are indeed correct? We originally checked these three times to make certain but, we put it back together and overextended the HTOB. This is our second shot and we would like to make sure it's correct this time before putting it back together.

Pressure Plate Finger to Bellhousing: 2.158
HTOB Ext: 1.861
HTOB Compressed: 2.630
Total Travel: .769
1/3 Travel: .256
2/3 Travel: .512

Any help would be greatly appreciated.

Thanks,
Tommy

[This message has been edited by CorvetteFan86 (edited 07-08-2018).]

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Report this Post07-08-2018 08:35 PM Click Here to See the Profile for olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
Perhaps a drawing with measurements would clarify your problem's description....
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fieroguru
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Report this Post07-08-2018 08:38 PM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
I got your PM, but will answer it here...

First impressions are the range of motion is a little less than normal and I think you flipped the 30/70 dimensions when you did your math to determine if you needed a spacer.

It normally is around 0.877" and yours is only .769" (roughly 0.108" less). Did you have the bleeder assy installed and open when taking the measurements? If not, then the fully compressed number will be off because fluid will be trapped inside.

HTOB fully retracted should be very close to 2.776". Your measurement is: 2.630" which is about 0.146" shorter... This is where the .108" difference above is likely coming from.

HTOB fully extended should be very close to 1.899" and yours (1.861") is within about 0.038", which is good.

You want 30% of the range of motion for wear and 70% for clutch release.

Using my historical numbers, the ideal pressure plate fingers would be 2.776 - (0.30 * 0.877) = 2.513" +/- about 0.030. The spacer needed would be 2.513-2.158 = 0.355" +/- 0.030"

Using your numbers (which I think are suspect): 2.630 - (0.30 * 0.769) = 2.399". The spacer needed would be 2.399 - 2.158 = .241" +/- 0.30"

[This message has been edited by fieroguru (edited 07-08-2018).]

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CorvetteFan86
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Report this Post07-08-2018 09:19 PM Click Here to See the Profile for CorvetteFan86Click Here to visit CorvetteFan86's HomePageSend a Private Message to CorvetteFan86Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by fieroguru:

I got your PM, but will answer it here...

First impressions are the range of motion is a little less than normal and I think you flipped the 30/70 dimensions when you did your math to determine if you needed a spacer.

It normally is around 0.877" and yours is only .769" (roughly 0.108" less). Did you have the bleeder assy installed and open when taking the measurements? If not, then the fully compressed number will be off because fluid will be trapped inside.

HTOB fully retracted should be very close to 2.776". Your measurement is: 2.630" which is about 0.146" shorter... This is where the .108" difference above is likely coming from.

HTOB fully extended should be very close to 1.899" and yours (1.861") is within about 0.038", which is good.

You want 30% of the range of motion for wear and 70% for clutch release.

Using my historical numbers, the ideal pressure plate fingers would be 2.776 - (0.30 * 0.877) = 2.513" +/- about 0.030. The spacer needed would be 2.513-2.158 = 0.355" +/- 0.030"

Using your numbers (which I think are suspect): 2.630 - (0.30 * 0.769) = 2.399". The spacer needed would be 2.399 - 2.158 = .241" +/- 0.30"



fieroguru,

Thank you very much for the information. I really appreciate it. I'll check on the numbers again tomorrow and get back to you on this thread. Just to give you a heads up, the clutch, pressure plate and flywheel are all the spec "F23" kit. Part number SC94AC.

[This message has been edited by CorvetteFan86 (edited 07-08-2018).]

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f85gtron
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Report this Post07-08-2018 11:34 PM Click Here to See the Profile for f85gtronSend a Private Message to f85gtronEdit/Delete MessageReply w/QuoteDirect Link to This Post
according to the numbers posted:
your current setup yields .47 in. play before the htob even makes contact with the clutch fingers. More play if the htob wasn't completely seated when measured.
that only provides .29 in. finger travel....not quite enough to reset the htob and squeeze all the fluid back out. you'll want to reduce the .47 number down to about .25 - .30 in. to leave room for wear. .17-.20 spacer will be needed, using the measurements posted.
hopefully someone with more experience will chime in and double check the math.
I blew one out myself and figured it out the hard way.
after the fact, somebody told me just to buy the clutch for the caviler that the trans came from and that should work too. i didn't try that because i already purchaced my fiero clutch.
Hope this helps.
Rom
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CorvetteFan86
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Report this Post07-14-2018 01:09 PM Click Here to See the Profile for CorvetteFan86Click Here to visit CorvetteFan86's HomePageSend a Private Message to CorvetteFan86Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by fieroguru:

I got your PM, but will answer it here...

First impressions are the range of motion is a little less than normal and I think you flipped the 30/70 dimensions when you did your math to determine if you needed a spacer.

It normally is around 0.877" and yours is only .769" (roughly 0.108" less). Did you have the bleeder assy installed and open when taking the measurements? If not, then the fully compressed number will be off because fluid will be trapped inside.

HTOB fully retracted should be very close to 2.776". Your measurement is: 2.630" which is about 0.146" shorter... This is where the .108" difference above is likely coming from.

HTOB fully extended should be very close to 1.899" and yours (1.861") is within about 0.038", which is good.

You want 30% of the range of motion for wear and 70% for clutch release.

Using my historical numbers, the ideal pressure plate fingers would be 2.776 - (0.30 * 0.877) = 2.513" +/- about 0.030. The spacer needed would be 2.513-2.158 = 0.355" +/- 0.030"

Using your numbers (which I think are suspect): 2.630 - (0.30 * 0.769) = 2.399". The spacer needed would be 2.399 - 2.158 = .241" +/- 0.30"



We've bought a new HTOB and double/triple checked the numbers and this is what we've come up with:

HTOB Retracted - 2.738
HTOB Extended - 1.881
Fingers - 2.188
Travel - .857


2.738 - (.30 x .857) = 2.481

Spacer needs to be 2.481 - 2.188 = .293 +/- .030

Is this correct fieroguru?

[This message has been edited by CorvetteFan86 (edited 07-14-2018).]

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fieroguru
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Report this Post07-14-2018 02:54 PM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
Those measurements are pretty close the ones I have seen before, which is a good thing.

I would agree you need a 0.300" spacer.
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