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Auto to Manual trans swap

chaynes12

Jr. Member
Joined
Feb 4, 2018
Messages
86
I have a 1972 model 302 that came with auto c4 transmission. Swapping it back to 3 speed manual. I am at the point of taking off the flex plate and putting a flywheel on it. The bolt holes on the crank won't seem to line up. Does something have to be swapped here?? This is the first time I have ever messed with a transmission, so I don't really know too much about it. Any help or pointers would be appreciated.
 

bronkenn

Contributor
Bronco Guy
Joined
Apr 27, 2017
Messages
2,662
Loc.
Southeast Ohio
Keep rotating the flywheel until the holes line up. I don't think those holes are indexed equally if my memory serves me correctly. Ken
 

El Kabong

Contributor
Driving stuff Henry built
Joined
Oct 8, 2009
Messages
1,487
x2. The flywheel is part of the balance for the crank & will only go on one way.

There also was a change in the weight of the balance at some point. It is important that the balance of the flywheel is correct for the crank. I don't know if hole pattern is different between those flywheels.
 
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chaynes12

Jr. Member
Joined
Feb 4, 2018
Messages
86
Thanks guys. Just went down and rotated a few times and it finally found the right position. All the bolts went in fine. But they didn't really seem to penetrate the crank flange far enough. Again, I don't know much about this but just throwing it out there. Is this normal??
 
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chaynes12

Jr. Member
Joined
Feb 4, 2018
Messages
86
Let me re-phrase.... They went in far enough to bite and snug down, but it seems to me that they would probably need to be in there a little further????
 

Viperwolf1

Contributor
electron whisperer
Joined
Aug 23, 2007
Messages
24,316
Let me re-phrase.... They went in far enough to bite and snug down, but it seems to me that they would probably need to be in there a little further????
If you are saying the old flywheel bolts are too long to use with a flexplate you would be correct. Get flexplate bolts.
 
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chaynes12

Jr. Member
Joined
Feb 4, 2018
Messages
86
Im actually referencing the opposite. The ones i have were used on an auto tranny with a flexplate but I am swapping to a manual transmission with flywheel. But it sounds like you are saying the flywheel bolts are longer. This would make sense with my question. I guess I need to buy flywheel bolts?
 

B RON CO

Contributor
Bronco Guru
Joined
Jun 29, 2016
Messages
2,412
Loc.
Statesville, NC
Hi, yes you need longer bolts for the flywheel. It is thicker. You should also use thread sealant because on many cranks the bolt hole is open into the back of the crank case. Good luck
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,875
Motor plate is different too and you will need a starter for a manual transmission. loctite the bolts for the pressure plate too. Always use a new through out bearing and pilot bearing/bushing. Get a clutch alignment tool when you bolt up the pressure plate.
 
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chaynes12

Jr. Member
Joined
Feb 4, 2018
Messages
86
I'm a little confused on what the pilot bearing is. I look into the back side of my crank and its just a smooth hole with no sign of any sort of bearing. It used to be paired with a automatic tranny. We are converting to a manual. Does this make a difference?? I have never done this before so I am not really knowledgable about transmissions. Any help??
 
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chaynes12

Jr. Member
Joined
Feb 4, 2018
Messages
86
Also, got to thinking... It originally had an automatic transmission. Ive done a little research and what i have found; it seems to me that if it had an automatic tranny, then it doesn't have a pilot bearing in there because the torque converter went in that area. Is this correct?? Anyone please try and explain this and get me pointed in the right direction.
 

sykanr0ng

Bronco Guru
Joined
Aug 11, 2014
Messages
5,363
I'm a little confused on what the pilot bearing is. I look into the back side of my crank and its just a smooth hole with no sign of any sort of bearing. It used to be paired with a automatic tranny. We are converting to a manual. Does this make a difference?? I have never done this before so I am not really knowledgable about transmissions. Any help??

Also, got to thinking... It originally had an automatic transmission. Ive done a little research and what i have found; it seems to me that if it had an automatic tranny, then it doesn't have a pilot bearing in there because the torque converter went in that area. Is this correct?? Anyone please try and explain this and get me pointed in the right direction.

If it came with an automatic the manufacturer would not put a bushing or bearing in the crankshaft because it is not needed for an automatic.

Parts cost money, any time a manufacturer can save money by not installing a part which is not needed they will.
 
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chaynes12

Jr. Member
Joined
Feb 4, 2018
Messages
86
If it came with an automatic the manufacturer would not put a bushing or bearing in the crankshaft because it is not needed for an automatic.

Parts cost money, any time a manufacturer can save money by not installing a part which is not needed they will.

so if i were to just buy one from summit and put it in, I would be good to go?
 
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chaynes12

Jr. Member
Joined
Feb 4, 2018
Messages
86
Alrighty. I appreciate it!! But when I go to put it in, will I need a special tool to install it? Or how do I go about that?
 

Viperwolf1

Contributor
electron whisperer
Joined
Aug 23, 2007
Messages
24,316
Also, got to thinking... It originally had an automatic transmission. Ive done a little research and what i have found; it seems to me that if it had an automatic tranny, then it doesn't have a pilot bearing in there because the torque converter went in that area. Is this correct?? Anyone please try and explain this and get me pointed in the right direction.
That is correct. The front pilot of the converter fits into the space that would be used by the bushing.
 
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