Help with flexplate

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Ryan ekes

Ryan ekes

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Does anyone know where to get a flexplate for a 340/727 transmission with a symmetrical bolt pattern for the converter. I'm getting 3 bolts in and the last hole doesn't match up it's about a half a hole off. I'm sure it's a newer converter which is causing the problem here just dunno if I can use a flexplate for a newer vehicle and have everything still match up. All advice is appreciated
 
Last edited by a moderator:
Ryan ekes said:
Does anyone know where to get a flexplate for a 340/727 transmission with a symmetrical bolt pattern for the converter. I'm getting 3 bolts in and the last hole doesn't match up it's about a half a hole off. I'm sure it's a newer converter which is causing the problem here just dunno if I can use a flexplate for a newer vehicle and have everything still match up. All advice is appreciated
Click to expand...

Usually it's a lot simpler to egg the hole enough to get the bolt in.
 
I have yet to see a converter built for a 727 with a symmetrical bolt pattern unless it was a one off order. I think Kim is right that you just need to spin it till all are lined up
 
there is always the remote posibility that you have the flex plate backwards and that is why the ofset hole wont line up

and that is assuming it was all working together at one point, and we dont have a bunch of mismatched parts
 
diymirage said:
there is always the remote posibility that you have the flex plate backwards and that is why the ofset hole wont line up...
Click to expand...
I don't think you can put the flex plate on the engine backwards because of the crankshaft holes not being equally spaced either.
 
Yeah I tried that when I installed it initially. left the bolts loose for some slop even. Disconnected the transmission pulled the flexplate off and double checked that way too and it's still not getting the last bolt. At most I'm getting a half a hole but if the hole was dead center it would go is why I'm wondering if it could be symmetrical

oldkimmer said:
1 hole is offset, u need to turn the converter till it lines up. Usually it's 4 times. Kim[/QUOTE
Click to expand...
 
fishy68 said:
I have yet to see a converter built for a 727 with a symmetrical bolt pattern unless it was a one off order. I think Kim is right that you just need to spin it till all are lined up
Click to expand...
Yeah I tried that when I first ran into the problem then pulled the trans then the flexplate and double checked that way too and still no luck at best I get a half a hole but if the hole was centered up on the flexplate like the rest it would bolt up perfectly is why I'm wondering if it's possibly symmetrical. Or maybe it's just a default from the factory idk at this point
 
krazykuda said:
You have to match what you have with the flex plate...

They come in symmetrical and non-symmetrical bolt pattern for the crank..

Then 10" or 11" for the torque converter pattern...


Find what you have and Mancini has them for $16:

Mancini Racing

10" symmetrical:

Mancini Racing Flex Plate


10" offset:

Mancini Racing Flex Plate


11" symmetrical:

Mancini Racing Flex Plate


11" offset:

Mancini Racing Flex Plate
Click to expand...
krazykuda said:
You have to match what you have with the flex plate...

They come in symmetrical and non-symmetrical bolt pattern for the crank..

Then 10" or 11" for the torque converter pattern...


Find what you have and Mancini has them for $16:

Mancini Racing

10" symmetrical:

Mancini Racing Flex Plate


10" offset:

Mancini Racing Flex Plate


11" symmetrical:

Mancini Racing Flex Plate


11" offset:

Mancini Racing Flex Plate
Click to expand...
T
krazykuda said:
You have to match what you have with the flex plate...

They come in symmetrical and non-symmetrical bolt pattern for the crank..

Then 10" or 11" for the torque converter pattern...


Find what you have and Mancini has them for $16:

Mancini Racing

10" symmetrical:

Mancini Racing Flex Plate


10" offset:

Mancini Racing Flex Plate


11" symmetrical:

Mancini Racing Flex Plate


11" offset:

Mancini Racing Flex Plate
Click to expand...
krazykuda said:
You have to match what you have with the flex plate...

They come in symmetrical and non-symmetrical bolt pattern for the crank..

Then 10" or 11" for the torque converter pattern...


Find what you have and Mancini has them for $16:

Mancini Racing

10" symmetrical:

Mancini Racing Flex Plate


10" offset:

Mancini Racing Flex Plate


11" symmetrical:

Mancini Racing Flex Plate


11" offset:

Mancini Racing Flex Plate
Click to expand...
It's a ten inch bolt pattern and the one I have bolts up to the crank perfectly it's just getting the last bolt in the converter I'm having problems with
 
Ryan ekes said:
T


It's a ten inch bolt pattern and the one I have bolts up to the crank perfectly it's just getting the last bolt in the converter I'm having problems with
Click to expand...

Then figure out if your crank is symmetrical or offset and get the proper 10" flex plate to match...
 
Last edited:
Ryan ekes said:
T


It's a ten inch bolt pattern and the one I have bolts up to the crank perfectly it's just getting the last bolt in the converter I'm having problems with
Click to expand...

fishy68 said:
It's not the crank that's the problem Karl. He said the torque converter is what's not lining up right
Click to expand...


Oh, so you have the correct crank bolt pattern, but you can't line up the last bolt for the converter???

Are you starting all of the bolts in the pattern before tightening them???

Sometimes it helps to keep it "loose" until all the bolts have been started, then tighten them...

If that doesn't work, then drill the hole one size bigger or egg shape it and see if the bolt will go in
 
krazykuda said:
Oh, so you have the correct crank bolt pattern, but you can't line up the last bolt for the converter???

Are you starting all of the bolts in the pattern before tightening them???

Sometimes it helps to keep it "loose" until all the bolts have been started, then tighten them...

If that doesn't work, then drill the hole one size bigger or egg shape it and see if the bolt will go in
Click to expand...
Yeah I talked to the guy who built it and he told me the converter was from a late model transmission and that's why I was having problems
 
Here is a PDF file showing the 4 different flex plates Chrysler used from 1962 to 2001 on both the 904 and the 727. You say the converter if from a "late model" transmission, do you know what year the transmission is? Any ID markings on the converter?
The " even / uneven" bolt holes refer to the crank shaft bolt holes. Both Kim and Fishy 68 posts are right. 30+ years in the converter industry and like Fishy68 I never saw a symmetrical bolt pattern on a stock 727 converter. Even our high stalls, unless it was some special order, used the Factory bolt pattern.
 

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transman said:
Here is a PDF file showing the 4 different flex plates Chrysler used from 1962 to 2001 on both the 904 and the 727. You say the converter if from a "late model" transmission, do you know what year the transmission is? Any ID markings on the converter?
The " even / uneven" bolt holes refer to the crank shaft bolt holes. Both Kim and Fishy 68 posts are right. 30+ years in the converter industry and like Fishy68 I never saw a symmetrical bolt pattern on a stock 727 converter. Even our high stalls, unless it was some special order, used the Factory bolt pattern.
Click to expand...
Thanks man I appreciate the information I'll look it up when I get home from work
 
A Magnum 5.2 flexplate is nuetral balance and symetrical pattern. Get one for a 96 or later.
 
Or do u have a 1996 or later converter, if so u will have to change it as it will not work with ur 727. U will have a lock up converter. Is ur 727 a lock up trans? Is the last inch or so on the input shaft smooth as in no splines for the last inch. Kim
 
oldkimmer said:
Or do u have a 1996 or later converter, if so u will have to change it as it will not work with ur 727. U will have a lock up converter. Is ur 727 a lock up trans? Is the last inch or so on the input shaft smooth as in no splines for the last inch. Kim
Click to expand...
Yeah it's a lockup trans with an overdrive
 
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