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Flexplate bolts not threaded all the way - can't bolt down flexplate

DanWheeler

Bronco Guru
Joined
Nov 8, 2005
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2,549
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Kirkland, WA
I bought some flexplate bolts that dont seem to work because they are not threaded all the way to the head and my flex plate is very thin therefore I can't screw them in all the way to tighten down the flexplate. I checked flexplate bolts on summit and they look about the same.

Am i missing something here?

thanks,
dan
 

broncnaz

Bronco Guru
Joined
May 22, 2003
Messages
24,341
Are you sure you didnt get flywhell bolts? How long is the shoulder? flex plate bolts usually have a very short shoulder compared to flywheel bolts Some also use washers underneath.
 

broncomitch

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Jan 17, 2008
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2,384
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west jordan, utah
i bought a set of fly wheel bolts from ARP and it was for a clutch plate.

so had to cut them to fit. sounds like you got the longer bolts for a clutch plate.
 

cgbexec

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Sep 19, 2006
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2,071
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Naples, FL
I had the same issue with my clutch plate bolts not fitting correctly. I just had to search around and find the proper sized bolts with the correct shoulder set up.
 
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DanWheeler

DanWheeler

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the shoulder is very small, maybe 3/16 inch and they come with lock washers but the shoulder is still too long to allow them to thread in all the way. They ARE shorter and have smaller heads than the pressure plate bolts I removed.

I can see the need for a small shoulder so the flexplate is not contacting threaded surface on the bolt. I guess I'll just need to look around for something with about a 1/8 inch shoulder. Thats about how thick my flexplate probably is maybe a little less plus the washers will take up some of that shoulder.
 
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DanWheeler

DanWheeler

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This is turning out to be a real pain. I drove all around town today looking for a place that sold the right bolts. Most places just dont have anything and have a hard time looking it up in their books.

I bought a 7/16-20 die to see if I can thread up the shoulder enough to make it work. I think the bolt will be too hard though. Worth a try for 3 bucks.
 

Viperwolf1

Contributor
electron whisperer
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Aug 23, 2007
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Should be able to get them at a wrecking yard. Ford dealer may even have them.
 

trlblazr

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May 8, 2007
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Mesa AZ
This is turning out to be a real pain. I drove all around town today looking for a place that sold the right bolts. Most places just dont have anything and have a hard time looking it up in their books.

I bought a 7/16-20 die to see if I can thread up the shoulder enough to make it work. I think the bolt will be too hard though. Worth a try for 3 bucks.

If you use a HEAVY cutting oil and only take a small "cut" and back it off you can cut grade 8 bolts
 
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DanWheeler

DanWheeler

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Joined
Nov 8, 2005
Messages
2,549
Loc.
Kirkland, WA
If you use a HEAVY cutting oil and only take a small "cut" and back it off you can cut grade 8 bolts


thats the plan... hope it works. I really wanna get this thing in and dont want to wait for a shipment from summit that may be the same bolts I already have.

Is a thick lock washer out of the question?
 

broncnaz

Bronco Guru
Joined
May 22, 2003
Messages
24,341
I doubt a $3 die will even touch those bolts. Luckily its external threads and not something internal.
I could be wrong as its been a while since I've messed with a auto but isnt there a Shim or spacer plarte that goes between the flexplate and crank? I seem to recall one but maybe it wasnt on a 302/c-4 combo.
Or I'd check and see if standard thick lock washers will work just make sure they dont cause any interferance with the torque converter make fure it fully seats.
 

Viperwolf1

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I could be wrong as its been a while since I've messed with a auto but isnt there a Shim or spacer plarte that goes between the flexplate and crank? I seem to recall one but maybe it wasnt on a 302/c-4 combo.

Some flexplates had them, some didn't. EB's had 2 different flexplate styles. My 10.5" bolt pattern plate didn't have one. Newer AOD style plates don't use them.
 
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DanWheeler

DanWheeler

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Nov 8, 2005
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2,549
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Kirkland, WA
Problem solved!

Screwdriver: depth of holes in crank
Top bolt: Mr Gasket flexplate bolts I extended the threads with a die
Middle bolt: Mr Gasket flextplate bolts straight out of the box
Bottom bolt: One of the flywheel bolts I pulled out

599389293_H37Rw-L.jpg
 
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