C4 flexplate - 164 tooth, 11.5 bolt pattern

[daddyo]

Did all Broncos come with a 164 tooth flexplate on
a 11.5" bolt pattern?

Bronco Graveyard sells new flexplates, part # 11130
for '73, '74, and '77 Broncos. My understanding is that
the '75 and '76 models used a different size (10.5"
bolt pattern maybe?) flex plate. What's the difference?

What do I need to change in order to use the "standard"
flex plate on a '76 transmission?

Do I need a new torque converter AND a new motor
plate?

Andrew

 

[2badrotties]

Broncohowie is our transmission guy, he will know. I can say this though. I have a 75 with a wierd converter/flexplate combo. The converter is smaller and the bolt pattern is NOT the same as normal. If you have that set-up, the converter will have a small cone welded to the very end of the converter hub where it slides into the back of crank. If you DO NOT have that extra cone welded on the converter, you should be okay with the normal flex plate.

 

[iwlbcnu]

If you have the 164 tooth flex than it is the standard, if it is 157 tooth it is odd ball. I thought only some 75's used the odd ball. i have 5 set-ups and only one was the 157.

 

[BwoncoHowie]

Did all Broncos come with a 164 tooth flexplate on
a 11.5" bolt pattern?

Bronco Graveyard sells new flexplates, part # 11130
for '73, '74, and '77 Broncos. My understanding is that
the '75 and '76 models used a different size (10.5"
bolt pattern maybe?) flex plate. What's the difference?

What do I need to change in order to use the "standard"
flex plate on a '76 transmission?

Do I need a new torque converter AND a new motor
plate?

Andrew

12 or 11 Inch Torque Converter?
If you have a '74 uncommon setup on your C-4, the torque converter will have an extended cup welded to the tip of the pilot and might have 2 drain plugs 180* deg. from each other. This combo wasn't specific to Bronco only and could be found on many trucks between late 73 to 76 F-100s E-100,200s. Unfortunately that flexplate is not available any more from Ford. If you need to replace your flexplate and cannot locate the one used with the 11” TC (OE #D3OZ-6375-A)
, you will need to convert both flexplate and torque converter to the (larger diameter) torque converter types. Both flexplates will have the same diameter and balance weight, but the 4 holes where the converter studs go through will not match. The diameter of the replacement torque converter will be larger and have a wider 4-stud pattern. In essence what Ford did on this '74 oddball setup was, adapt a smaller passenger car Torque Converter to work in a truck application by designing a different flexplate and extending the pilot on the torque converter so that it would work in the larger/longer bell housing.
Both pieces you will need to convert your odd type flywheel setup Bronco to the 12" torque converter are;
ATC Aftermarket Technology Corp. part numbers-
Converter =#FM112 or FM124
Flexplate= #F200 (Ford OE#E0AZ-6375-A)
Both pieces can be purchased at your favorite local transmission repair shop. They may need to order the parts, and can usually get them by the next business day.

Part number info:
Flexplate, 164tooth C-4/FMX with 28 oz weight used with the extended cup pilot 11” torque converter = (Currently Obsolete)
(Ford OE #D3OZ-6375-A)

Flexplate, 164tooth C-4/AOD with 28 oz weight = ATC/RPM Part#F200 (Ford OE #E0AZ-6375-A)

Flexplate, 164tooth C-4/AOD with 50 oz weight = ATC/RPM Part#F209 (Ford OE #E2AZ-6375-A)

Sorry for the essay, Hope this helps, BH

 

[STICK76]

I had the same problem with my '76. I just replaced the motor and while we had it out we checked the fly wheel. Had a crack in it so we decided to replace it. Good luck finding one for a '76. Had to change the convertor to fix the problem.

Stick

 

[daddyo]

12 or 11 Inch Torque Converter?
If you have a '74 uncommon setup on your C-4, the torque converter will have an extended cup welded to the tip of the pilot and might have 2 drain plugs 180* deg. from each other. This combo wasn't specific to Bronco only and could be found on many trucks between late 73 to 76 F-100s E-100,200s. Unfortunately that flexplate is not available any more from Ford. If you need to replace your flexplate and cannot locate the one used with the 11” TC (OE #D3OZ-6375-A)
, you will need to convert both flexplate and torque converter to the (larger diameter) torque converter types. Both flexplates will have the same diameter and balance weight, but the 4 holes where the converter studs go through will not match. The diameter of the replacement torque converter will be larger and have a wider 4-stud pattern. In essence what Ford did on this '74 oddball setup was, adapt a smaller passenger car Torque Converter to work in a truck application by designing a different flexplate and extending the pilot on the torque converter so that it would work in the larger/longer bell housing.
Both pieces you will need to convert your odd type flywheel setup Bronco to the 12" torque converter are;
ATC Aftermarket Technology Corp. part numbers-
Converter =#FM112 or FM124
Flexplate= #F200 (Ford OE#E0AZ-6375-A)
Both pieces can be purchased at your favorite local transmission repair shop. They may need to order the parts, and can usually get them by the next business day.

Part number info:
Flexplate, 164tooth C-4/FMX with 28 oz weight used with the extended cup pilot 11” torque converter = (Currently Obsolete)
(Ford OE #D3OZ-6375-A)

Flexplate, 164tooth C-4/AOD with 28 oz weight = ATC/RPM Part#F200 (Ford OE #E0AZ-6375-A)

Flexplate, 164tooth C-4/AOD with 50 oz weight = ATC/RPM Part#F209 (Ford OE #E2AZ-6375-A)

Sorry for the essay, Hope this helps, BH

They offer both torque converters, FM112 and FM124, at a local parts
shop. Their website says that they are interchangeable, but the pilot on
FM112 is 1.28" long, and the pilot on FM124 is 1.36" long. Moreover,
FM112 is almost half again as expensive as FM124.

Does it matter which one I choose?

Andrew

 

[BwoncoHowie]

They offer both torque converters, FM112 and FM124, at a local parts
shop. Their website says that they are interchangeable, but the pilot on
FM112 is 1.28" long, and the pilot on FM124 is 1.36" long. Moreover,
FM112 is almost half again as expensive as FM124.

Does it matter which one I choose?

Andrew

It does matter to some, the FM124 has a ribbed shell where as the FM112 should have a smooth shell. The pilots may be said to be different but they were just tolerence variances, the attaching or mounting points should be exactly the same. The ribbed shells could possibly dissipate more heat, whereas the smooth shells could theoretically drain less horsepower. The 112s cost less because they are more plentyful and there is a surplus with that company.