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what is the difference between a flywheel and a flex plate?

  • Thread starter Thread starter jerry S
  • Start date Start date Jul 25, 2006
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jerry S

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Sep 3, 2003
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52.22N 5.12E
Jul 25, 2006
#1
  • Jul 25, 2006
  • #1
I must confess my ignorance. You may openly mock me after giving a good answer to the question.

jS
 

GoinBroke

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Jul 13, 2006
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Jul 25, 2006
#2
  • Jul 25, 2006
  • #2
Again, I am no expert but a flywheel is for manual tranny's and is thick in the starter engaging area (1/2"?) and the flex plate is for auto's and is thin in comparison.
 

A67StangMaster

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Jul 25, 2006
#3
  • Jul 25, 2006
  • #3
Ok A flexplate is what hits the starter to turn over the engine.
A Flywheel is what the cluch grabs on to when you shift.
you have a flexplate on both trannys.
but you can only have a flywheel on a manual tranny.
 

GoinBroke

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#4
  • Jul 25, 2006
  • #4
A67 stated it better as one has the clutch engaging surface but both have the starter engaging plate and the c'balence.
 
J

Jimmys66

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Jul 25, 2006
#5
  • Jul 25, 2006
  • #5
Can we start making fun of Jerry yet?
 
M

mustangman70

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Jul 25, 2006
#6
  • Jul 25, 2006
  • #6
A67StangMaster said:
Ok A flexplate is what hits the starter to turn over the engine.
A Flywheel is what the cluch grabs on to when you shift.
you have a flexplate on both trannys.
but you can only have a flywheel on a manual tranny.
Click to expand...

A+ :SNSign:
 
D

D.Hearne

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Jul 25, 2006
#7
  • Jul 25, 2006
  • #7
A67StangMaster said:
Ok A flexplate is what hits the starter to turn over the engine.
A Flywheel is what the cluch grabs on to when you shift.
you have a flexplate on both trannys.
but you can only have a flywheel on a manual tranny.
Click to expand...
Ok, I'm gonna let Jerry pass, and flunk you. The flexplate "HITS" the starter? No, I don't think that's the way it works. And both manual and auto's don't have flexplates. Only the Automatic uses a flexplate. It basically takes the flywheel's duty as far as starter engagement and counterweighting the crank, but it's thin and flexible, hence it's name. The torque converter full of fluid takes up the energy storage function of a Manual trans flywheel.
 

LUCAFU1

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Jul 26, 2006
#8
  • Jul 26, 2006
  • #8
D.Hearne said:
Ok, I'm gonna let Jerry pass, and flunk you. The flexplate "HITS" the starter? No, I don't think that's the way it works. And both manual and auto's don't have flexplates. Only the Automatic uses a flexplate. It basically takes the flywheel's duty as far as starter engagement and counterweighting the crank, but it's thin and flexible, hence it's name. The torque converter full of fluid takes up the energy storage function of a Manual trans flywheel.
Click to expand...


agreed.

next time you have a starter out the car get some jumping cables and hook up the starter to your battery. stick you finger (take the f/w flex plates place) in the starter right above the gear at the same time your buddy touches the positive side of the batt. then report back and let us if your finger hits the starter or if the starter hits you :Zip2:
 

jerry S

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Jul 26, 2006
#9
  • Jul 26, 2006
  • #9
Thanks for the clarification. I have a C6 for a SBF that got swapped into my car. Originally, my car had an FMX. If I peer through the engine bay to the top of the tranny case, I see the number "70" but I don't know what it means. I am guessing it means it came from a 1970 SBF. In the absence of taking apart the tranny to inspect the FP, how do I know whether I need a 157 or 164 tooth FP when the time comes to replace the stock one?
 

jerry S

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#10
  • Jul 26, 2006
  • #10
Jimmys66 said:
Can we start making fun of Jerry yet?
Click to expand...

Goinbroke, D.Hearne, and LUCAFU1 gave good answers to the question posed so they are free to openly mock my ignorance. The others may not.
 
D

D.Hearne

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#11
  • Jul 26, 2006
  • #11
I'm pretty sure all small block C-6's use the larger 164 tooth flexplate.
 

GoinBroke

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#12
  • Jul 26, 2006
  • #12
The way I have made sure in the past is use a paint pen and make a dot on one tooth and start counting. As Dhearne said it should be the 164T for that setup. When ordering the new one make sure to match the correct imbalence to your engine or you will get a bad case of the shakes.
 

Max Power

Active Member
Jul 31, 2003
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St Paul
Jul 26, 2006
#13
  • Jul 26, 2006
  • #13
A67StangMaster said:
Ok A flexplate is what hits the starter to turn over the engine.
A Flywheel is what the cluch grabs on to when you shift.
you have a flexplate on both trannys.
but you can only have a flywheel on a manual tranny.
Click to expand...

Seriously, where do you get this stuff? Sheesh.

Hearne is correct, as usual.
 

A67StangMaster

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Jul 26, 2006
#14
  • Jul 26, 2006
  • #14
Flexplate = Thin steel plate that bolts to the torque converter on an automatic transmission with a ring gear for the starter.

Flywheel = Thick cast iron machined disk that holds the clutch assy for a manual transmission with a ring gear for the starter.

They look all most the same but the manual trans one is much Heavy'er?

I was told that both tranny have flexplates. But I guess i was wrong since i never had a manual tranny I only had to read about it.
 

Jester67

Member
Sep 21, 2004
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Jul 26, 2006
#15
  • Jul 26, 2006
  • #15
A67StangMaster said:
Flexplate = Thin steel plate that bolts to the torque converter on an automatic transmission with a ring gear for the starter.

Flywheel = Thick cast iron machined disk that holds the clutch assy for a manual transmission with a ring gear for the starter.

They look all most the same but the manual trans one is much Heavy'er?

I was told that both tranny have flexplates. But I guess i was wrong since i never had a manual tranny I only had to read about it.
Click to expand...
This is not meant as an attack but a good rule is to not to post information that you do not have first hand knowledge about. If you feel you must post second hand knowledge then put a disclaimer in first that way the reader knows this in not first hand knowledge and weight it accordantly. I think this rule is what makes this place so great not a lot of the usual “my brothers friend said his uncle has one “kind of thing.
 

Max Power

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#16
  • Jul 26, 2006
  • #16
LOL...Jester, it's certainly not the first time.
 

A67StangMaster

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#17
  • Jul 26, 2006
  • #17
:Zip2: I am pretty sure you guys do the samething. Thats what I know and I guess the people that responded to what i said eather read the same thing or thats what they know too. I don't know why you guys have to insult people for making a mistake. Yea so i got it wrong I understand it better now we all make mistakes. You dont help someone by making fun of them. its like laughing at a disable child because he cant walk or talk right, instead of helping him learn and walk your just pushing him down and laughing at his face. Think about something before you post.

And Jester I understand what your saying. next time I will
 

Max Power

Active Member
Jul 31, 2003
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St Paul
Jul 26, 2006
#18
  • Jul 26, 2006
  • #18
A67Stangmaster, I will discount your thread where you called that Trans-Am Mustang a "ricer, (which was not very nice btw), but I have seen you give incorrect mechanical advice to people over the last few weeks. I have seen you give incorrect advice on rocker arms, water pumps, blueprinted oil pumps and flex plates in just the last two weeks.

We are not making fun of you, and we would like to help you learn, but if you are just learning, why are you giving people mechanical advice? That kind of advice is not helpful and could do damage.

It's nothing personal, it's just that giving people bad advice can cost people money or get them hurt. You are not a handicapped child (that comparison is quite dramatic) and you are giving advice on things you are unsure of with your own free will. If you don't know, don't post it.

You started a thread about starting your motor after sitting a long time, and that is a great way to learn. There are a lot of other that probably learned too. You don't learn by giving advice, you learn by asking.

I am certainly no expert on everything, and the things I am not 100% certain about, I don't give advice. I sit back and read. Or I ask the question.

If learning is your concern, that's the way to learn.
 
J

Jimmys66

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Nov 28, 2001
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Jul 26, 2006
#19
  • Jul 26, 2006
  • #19
jerry S said:
Goinbroke, D.Hearne, and LUCAFU1 gave good answers to the question posed so they are free to openly mock my ignorance. The others may not.
Click to expand...


Damnit! Jerry won't let me make fun of him until I think of something smart to say. It might be awhile. I'll get back to you.


Just havin' fun with you. I hate asking those questions I should know too.
 

xoxbxfx

Founding Member
May 9, 2001
3,959
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Southlake, TX
Jul 26, 2006
#20
  • Jul 26, 2006
  • #20
c6 = 164tooth
c4 = 157 tooth
 
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