I'm going to replace the ring gear bolts at the ARB locker.
Knowing that they have to be replaced everytime when loosened, I would like to know which grade they are. Nobody is able to tell me the bolt grade over here in our world of metric.
The bolt is a 3/8, 24G and has 7 protruding lines on it.
One picture tells more than 1000 words:
Thanks for your help!

What would be the best bolt to replace it?

 

wow.. thats the same way mine were.. marked really odd. it conforms to no spec I can find.

what is the torque spec? I would select a suitable grade according to that.

edit: it's most likely not a standard steel bolt, hence the odd markings

 

Seen lots of bolts - but none ever like that.

 

That is a grade 7 sae bolt
usualy metrics have a # stamped in the head 4,5,6,7,8, and so on with no marks
this is the best I can remember

 

grade 7 has 5 lines, grade 8 has 6

 

ARB asks for a torque of 75Nm or 55ftlb.
As a metric bolt that would be a 10mm, 10.9 bolt with a torque about 79Nm.

Thats not an ultimate bolt for a ring gear application...

 

10.9 is a hair weaker than grade 8...

you would probably be ok with that grade.. but I have a feeling that ring gear bolts are made with a really high tensile strength.. if I remember right mine torqued into the 200ftlb range.

It might just be best to order a set to have piece of mind..

 

Hmm, seems like another job for ARP bolts?
I don't won't these bolts to fail.

 

ARP might just be overkill.. but i'm pretty sure they make them for a hefty price.

 

...of course you can re-use the old ones and not using Loctite- like the TJ Jeeper with the self installed locker, I met on the trail with a grenaded rear end.
Four or five bolts were fallen out, the rest was sheared off.

I'm normally really not the person to find joy in another's misfortune- but in this case I laughed my butt off, because we told him in advance...