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How far can TQ be pushed back when separated from flexplate?


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Hi guys,

I reinstalled the FMX into my Mach 1 about a year ago and I guess I mismatched the relationship of torque converter and flexplate when bolting them together (at least, is there a given relationship at all and does it matter?). I feel a slight vibration when revving up.

Can the TQ be unbolted, pushed back to get the studs out of the flexplate holes and be rotated to the next hole without unbolting the bellhousing?

 

Michael

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Spechti,

 

What was the purpose for the removal? Unfortunately, you are going to have unbolt the bell housing. If memory serves me right, the FMX may have had a drain plug that should have matched up with hole in the flywheel. Do you remember seeing a draining plug in your TQ?

 

It is possible that the Harmonic balancer could be having problems?

 

mustang7173

Thanks,

mustang7173 🇺🇸

"Courage is being scared to death but saddling up anyway" -- John Wayne

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.

the tq has a drain bolt . . there is only one hole in the flex plate for this bolt so yes it needs to be clocked correctly.

 

if this bolt does not line up with the hole, it may push on the flex plate possibly causing a vibration.

 

sometimes the converter will back off far enough to rotate it sometimes it will not . . just have to try and see and hope.

.

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The plug is aligned with the hole next to the stud and it can be drained through that hole. But as far as I remember, there are at least 2 opposite holes for the drain plug on the flexplate. You can mount the converter in at least two positions, 180° apart from each other.

 

The converter was changed due to trans overhaul and a groove in the shaft. I will remove the four nuts and push it back...

 

The harmonic balancer may also be a candidate for the vibration. It was also changed during engine rebuild. It is from pioneer.

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If the torque converter has studs you will not be able to push it back far enough to rotate it independently from the flex plate, at least I don't think you will. If it has bolts you probably can.

73 conv. 460, D0VE large valve heads, Performer RPM manifold, Voodoo 227/233 cam, Holley 950 HP carb, C6 trans, 3.25 trak-loc.

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The harmonic balancer may also be a candidate for the vibration. It was also changed during engine rebuild. It is from pioneer.

 

I had a pioneer on my engine.. And it had a vibration. I swapped the stock dampener on, and it got better.

1973 Mach 1 Q code 351 4V, 9A paint, standard interior, 3.50 rear, C6 trans.

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  • 1 year later...

Hi Totalled,

that's exactly what I experienced with my Pioneer balancer. Vibration got worse with it on the engine. Changed back to the original Ford part. It is better, but not gone. Got a second, used FMX with a new Boss Hog TQ and new flexplate. Will change them in the spring.

 

 

The harmonic balancer may also be a candidate for the vibration. It was also changed during engine rebuild. It is from pioneer.

 

I had a pioneer on my engine.. And it had a vibration. I swapped the stock dampener on, and it got better.

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Guest Pastel Blue

On my recent BB rebuild, I had the rotating assembly completely balanced from the harmonic balancer back to and including the flexplate. The flexplate is new as when I got the car,, the starter was chewing the teeth on the flexplate. Both needed replacing during the rebuild. We had to add some weight to the flexplate to complete the overall balancing.

 

When I sent my C-6 in to be rebuilt, I was the informed that the front pump required changing due to the torque converter pushing back on the pump causing permanent damage to the pump... I learned there was no play for the torque converter to move back and forth slightly which caused it to create additional transmission damage.

 

There should be some play allowed for between the torque converter and the flexplate, but I do t think it will be such that you can push it back far enough so that the studis are clear and the torque converter can be rotated, that would seem like excess play to me...

 

I haven't bolted up my rebuilt engine, new flexplate, rebuilt torque converter and transmission yet, but I will ensure that there is some play there to ensure I don't experience what was happening with the car when I got it. I am not sure yet, what the PO did to create this problem.

 

Good luck with your scenario.

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On my recent BB rebuild, I had the rotating assembly completely balanced from the harmonic balancer back to and including the flexplate. The flexplate is new as when I got the car,, the starter was chewing the teeth on the flexplate. Both needed replacing during the rebuild. We had to add some weight to the flexplate to complete the overall balancing.

 

When I sent my C-6 in to be rebuilt, I was the informed that the front pump required changing due to the torque converter pushing back on the pump causing permanent damage to the pump... I learned there was no play for the torque converter to move back and forth slightly which caused it to create additional transmission damage.

 

There should be some play allowed for between the torque converter and the flexplate, but I do t think it will be such that you can push it back far enough so that the studis are clear and the torque converter can be rotated, that would seem like excess play to me...

 

I haven't bolted up my rebuilt engine, new flexplate, rebuilt torque converter and transmission yet, but I will ensure that there is some play there to ensure I don't experience what was happening with the car when I got it. I am not sure yet, what the PO did to create this problem.

 

Good luck with your scenario.

 

Ford has 2 different sized hubs (or possibly more?) on the snout of the torque converter. Since you had a situation where there was improper end play on the converter, I suggest you check the hub diameter along with the end of the crankshaft. There are adapter rings which allow the use of the smaller hub converter on a crank with larger pilot bushing bore...it's possible someone installed a mismatched converter relative to your crankshaft pilot bushing bore.

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Guest Pastel Blue

On my recent BB rebuild, I had the rotating assembly completely balanced from the harmonic balancer back to and including the flexplate. The flexplate is new as when I got the car,, the starter was chewing the teeth on the flexplate. Both needed replacing during the rebuild. We had to add some weight to the flexplate to complete the overall balancing.

 

When I sent my C-6 in to be rebuilt, I was the informed that the front pump required changing due to the torque converter pushing back on the pump causing permanent damage to the pump... I learned there was no play for the torque converter to move back and forth slightly which caused it to create additional transmission damage.

 

There should be some play allowed for between the torque converter and the flexplate, but I do t think it will be such that you can push it back far enough so that the studis are clear and the torque converter can be rotated, that would seem like excess play to me...

 

I haven't bolted up my rebuilt engine, new flexplate, rebuilt torque converter and transmission yet, but I will ensure that there is some play there to ensure I don't experience what was happening with the car when I got it. I am not sure yet, what the PO did to create this problem.

 

Good luck with your scenario.

 

Ford has 2 different sized hubs (or possibly more?) on the snout of the torque converter. Since you had a situation where there was improper end play on the converter, I suggest you check the hub diameter along with the end of the crankshaft. There are adapter rings which allow the use of the smaller hub converter on a crank with larger pilot bushing bore...it's possible someone installed a mismatched converter relative to your crankshaft pilot bushing bore.

 

I am pretty sure this is the original torque convertor for this car's application. There has been some discussion in the past whether the Code 63 or 65 was correct, but I can't be sure that this wasn't changed out at some time. I intend to check for proper fit/clearance/play when I go to bolt up the transmission in the near future. If anyone has anything to add based on these shots, let me know. Thanks

216340367_vert71429cjtorqueconvert.jpg.1ea46d380b31ecdbc8d63d819565ba72.jpg

1178476152_vert71429cjtorqueconvert2.jpg.c9df4376963df57e9e086de56f0f7093.jpg

267726311_vert71429cjtorqueconvert4.jpg.b4f84b3807b1131c20623b82bb0d2432.jpg

1316996261_vert71429cjtorqueconvert3.jpg.3e4d9ee2a366d07b60083ff9636eec45.jpg

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On my recent BB rebuild, I had the rotating assembly completely balanced from the harmonic balancer back to and including the flexplate. The flexplate is new as when I got the car,, the starter was chewing the teeth on the flexplate. Both needed replacing during the rebuild. We had to add some weight to the flexplate to complete the overall balancing.

 

When I sent my C-6 in to be rebuilt, I was the informed that the front pump required changing due to the torque converter pushing back on the pump causing permanent damage to the pump... I learned there was no play for the torque converter to move back and forth slightly which caused it to create additional transmission damage.

 

There should be some play allowed for between the torque converter and the flexplate, but I do t think it will be such that you can push it back far enough so that the studis are clear and the torque converter can be rotated, that would seem like excess play to me...

 

I haven't bolted up my rebuilt engine, new flexplate, rebuilt torque converter and transmission yet, but I will ensure that there is some play there to ensure I don't experience what was happening with the car when I got it. I am not sure yet, what the PO did to create this problem.

 

Good luck with your scenario.

 

Ford has 2 different sized hubs (or possibly more?) on the snout of the torque converter. Since you had a situation where there was improper end play on the converter, I suggest you check the hub diameter along with the end of the crankshaft. There are adapter rings which allow the use of the smaller hub converter on a crank with larger pilot bushing bore...it's possible someone installed a mismatched converter relative to your crankshaft pilot bushing bore.

 

+1

 

Measure the snout of the torque converter and the pilot hole in the flex plate when you take it apart.

 

EDIT!!!!

Measure the snout of the torque converter and the pilot hole in your crankshaft.

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The torque converter pilot registers in the crank, not the flexplate. Ford used two different sizes. 1.375 and 1.848. You need to measure the hole in the crank and use the appropriate converter.

 

The previous pump damage was probably the result of trying to mate the engine and transmission without the converter being fully seated on the input shaft splines. When the bell housing is against the mating surface of the block you should be able to move the converter back and forth between 1/8"-1/4" . If it is bound up there is something wrong and you will damage the pump if you tighten the bellhousing bolts.

73 conv. 460, D0VE large valve heads, Performer RPM manifold, Voodoo 227/233 cam, Holley 950 HP carb, C6 trans, 3.25 trak-loc.

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The torque converter pilot registers in the crank, not the flexplate. Ford used two different sizes. 1.375 and 1.848. You need to measure the hole in the crank and use the appropriate converter.

 

The previous pump damage was probably the result of trying to mate the engine and transmission without the converter being fully seated on the input shaft splines. When the bell housing is against the mating surface of the block you should be able to move the converter back and forth between 1/8"-1/4" . If it is bound up there is something wrong and you will damage the pump if you tighten the bellhousing bolts.

 

Thanks for correcting me!

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Guest Pastel Blue

The torque converter pilot registers in the crank, not the flexplate. Ford used two different sizes. 1.375 and 1.848. You need to measure the hole in the crank and use the appropriate converter.

 

The previous pump damage was probably the result of trying to mate the engine and transmission without the converter being fully seated on the input shaft splines. When the bell housing is against the mating surface of the block you should be able to move the converter back and forth between 1/8"-1/4" . If it is bound up there is something wrong and you will damage the pump if you tighten the bellhousing bolts.

 

+1 ^^^ My transmission guy also stated the 1/4" play - back and forth, which would be common sense as well. if things are too tight in there, you know ahead of time and need to check for the problem before forcing the issue...

 

My crank and convertor line up properly for fitment, that was not the issue. Based on the shoddy rebuild of the engine previously, the use of sub standard bolts, what ever they could find to put things back together; more than likely it was a poor torque convertor to input shaft splines fitting.

 

I have no intention of rushing the install, it will be done correctly.

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