ARP Bolt Torque Questions

[BPBP440]

I am using ARP Flex Plate Bolts, Torque Converter Bolts and Bell Housing Bolts for my 440/727.

The only torque value I found from ARP was for the Flexplate Bolts (7/16") - 75 ft-lbs using their assy lube.

For the other bolts they simply refer you to a spec sheet, which requires you to know the tensile strength of the fastener (which I did not see on the website).

Anyone know the correct torque specs for the ARP TC bolts (7/16) and the bell housing bolts (7/16 & 3/8)?

 

[69Bee]

8740 Chrome Moly: Until the development of today’s modern alloys, chrome moly was popularly considered a high strength material. Now viewed as only moderate strength, 8740 chrome moly is seen as a good tough steel, with adequate fatigue properties for most racing applications, but only if the threads are rolled after heat-treatment, as is the standard ARP production practice. Typically, chrome moly is classified as a quench and temper steel, that can be heat-treated to deliver tensile strengths between 180,000 and 210,000 psi.

ARP2000®: ARP2000 is an alloy steel that can be safely heat treated to a higher level, producing a greater strength material than 8740. While 8740 and ARP2000 share similar characteristics – ARP2000 is capable of achieving a clamp load at 220,000 psi. ARP2000 is used widely in short track and drag racing as an up-grade from 8740 chrome moly in both steel and aluminum rods. Stress corrosion and hydrogen embrittlement are typically not a problem, providing care is taken during installation.

I would say that your bolts are 8740 material unless they say ARP2000 on the head. I would use the 190K-200K column and torque to 50 Ft/lb for 3/8" and 80 Ft/lb for 7/16". The Flexplate kit 200-2903 instructions say to torque to 75 Ft/lb. ALL of these torques are with the ARP Moly Assy Lube. When you look up the part, there is a clickable button that says "Kit Instructions" to see them.

If you don't feel comfortable with these numbers, you can call them and ask for tech to get their recommendations.

 

[mopar 3 B]

All this about torque of the bolt and bolt thread is great but what about the female thread in the block and torque convertor? Nothing there has been upgraded and threads in cast and steel have their limits also.

 

[BPBP440]

All this about torque of the bolt and bolt thread is great but what about the female thread in the block and torque convertor? Nothing there has been upgraded and threads in cast and steel have their limits also.

That is a fair and concerning point.

 

[beanhead]

Their 7/16" converter bolts call for 55 with their lube.

FWIW---these specs are dandy--if you can get a torque wrench and socket in there in the first place
Doing this stuff with the components in the car is a "whole 'nother thang"!

 

[mopar 3 B]

I have always used the turn off the engine torque method. Have not had a converter bolt come loose yet.

 

[RemCharger]

Tight as you can go without smashing your knuckles,, and blue loctite . Red if you want extra insurance. I've never (ever ever ever) heard of someone putting the arp goop on a flex plate bolt. Recipe for disaster .