Flexplate bolts and TC bolts?

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coair73x

coair73x

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Getting ready to put a freshly built 727 back in my Duster and wondering if I should re use the Flexplate bolts with the B&M SFI external balanced 360 flexplate and the TC bolts. I plan to use Red Locktight on all I assume. Mild 360 built in 91 still runs strong.
 
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Not a big fan of red loctite. I once made the mistake of using red loctite on the fitting for the water pump bypass on a SB intake manifold. Impossible to remove without destroying stuff. Blue is good enough for most situations.
 
Stock bolts will work unless the flexplate and converter is intended for 7/16 bolts.

arp makes a nice product.

If you want to use locktite I'd use green or blue not the red. You want to get them out again. Lol
 
I went with the arp bolts and blue locktite. will resuse the crank bolts. I believe I just torq those down to 55 ft lbs and no locktite. I still am searching for torq converter bolts torque specs. they are 5/16
 
According to Arp they say to use the blue and torque to 75. That's the flex plate.
I have some extra new bolts but don't know the size will let you know Sunday when I get back.
 
meathead66 said:
According to Arp they say to use the blue and torque to 75. That's the flex plate.
I have some extra new bolts but don't know the size will let you know Sunday when I get back.
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flexplate to crank bolts? I have read specs from 55ft lbs to your 75. It is a B&M SFI for 360 LA.
 
I reused the crank bolts as they were in great condition. Flexplate is installed. I am going use the arp bolts for the converter.
 
in my 69 FSM the torque for the flex plate, to torque converter is 270 in lbs (22.5 ft lbs), thats on the last page of the tranny section. It says 55 ft lbs on the flex plate to crank bolts. I cant understand that big of a differance.

barracudadave67
 
barracudadave67 said:
in my 69 FSM the torque for the flex plate, to torque converter is 270 in lbs (22.5 ft lbs), thats on the last page of the tranny section. It says 55 ft lbs on the flex plate to crank bolts. I cant understand that big of a differance.

barracudadave67
Click to expand...
did you get that the right way around? I feel like the flex plate to TC spec was 55... and the crank bolts were less... maybe it's just too early in the morning - still having my first coffee
 
Crank to flexplate is higher torque, you will be sorry if you torque it 22 ft-lbs! it'll sound like it's knocking when you fire it up.i torqued mine to 75 with arp bolts and blue loctite.
 
yea ok - now that I stop and think about it - the crank bolts were a decent torque # - I had to hold the flex plate still while I tightened them because the crank shaft moved before I reached spec... but I feel like the spec for flex plate to TC was higher than 22.5... eh, no FSM in front of me and it is still early.. :D
 
Scamp Mike
I got the info from my 69 Plymouth Fac Service manual, pg 21-98, which is the "transmission tightening reference" page, which is the last page in the transmission section (21).
Siren74 is right, my flex plate came loose at the torque converter, and it sounded like a lower engine knock, or headers hitting frame rail, at idle. But I still can't figure out why their is such a difference in torque ft lbs between the crank, and torque converter.

barracudadave67
 
ScampMike said:
yea ok - now that I stop and think about it - the crank bolts were a decent torque # - I had to hold the flex plate still while I tightened them because the crank shaft moved before I reached spec... but I feel like the spec for flex plate to TC was higher than 22.5... eh, no FSM in front of me and it is still early.. :D
Click to expand...
Barracudadave67 is correct. If your converter to flexplate bolts are stock 5/16 size you'd never get them torqued to 55 ft. lbs before they snap
 
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