Torque converter bolt grade?

[Malicious]

Hi all

The ARP bolts I have for the torque converter are way too small. I've sourced a bolt that will fit (7/16 unf) but it's only grade 5 and needs to be cut down.

Is grade 5 high enough for a torque converter to flexplate? Or do I need a higher grade?

Thanks!

 

[2059]

You're first and best choice should always be factory (or engineered fasteners like ARP) torque converter bolts. Could you get away with GR5? Would I do it? No.

I'm sure someone here can help a brother out with supply.

 

[66Satellite47]

I'd stick with grade 8. Which bolts are you looking for, flex plate to crank or flex plate to converter? I'm guessing flex to converter since the ones you got are too small (stock low perf converter, 5/16). Looks like ARP 200-2903 (7/16-20 x 3/4 is the flex to crank bolt, might work.

Factory Hemi converter bolts were 7/16"-20 x 1/2" under head length with .200" head thickness. This was same as flex to crank bolts except those have a thicker head .260 UHL, those will hit the back of the block if used as flex to converter bolts. I have just ground down the head thickness on flex to crank bolts to .210" thickness & work fine.

Again this a place for grade 8.

 

[lewtot184]

use a grade 8 with loctite.

 

[Hemi 354]

Absolute agree with the Grade 8 assessment. Only way to go.

 

[Photon440]

You can get what the factory used http://www.ebay.ca/itm/OEM-Mopar-Fl...Parts_Accessories&hash=item339e1804b8&vxp=mtr

 

[bm02tj]

I would only use bolts designed for the job as grade 8 may be to hard
for the shear strength
also part of the strength is the clamp force and the grade 8 may not torque to yield

found one and it is grade 8 so it should be ok

 

[66Satellite47]

Yup, factory bolts are grade 8. The Ebay picture sure aren't factory with 12 point heads. Those are ARP Pro Series.

 

[Photon440]

Those aren't factory? Guess I shouldn't have believed Rick Ehrenberg. But they should still fit the same, don't you think?

What about these ones?http://www.summitracing.com/int/parts/dcc-4876820/overview/

 

[Bigal75]

Grade 8 - nothing less