I tore my rear end apart for a gear swap and the bolts on the left side of the posi had broke off sending the bolt heads between the carrier and the housing loosening a few ring gear bolts when they went by. I'm happy I caught it but not sure what the "fix" is gonna be.. I drilled the bolts and used an extractor and got the broken bolts out then tore the posi apart and cleaned all the shavings out and reassembled in Lucas.. Now I need new bolts..

They are M10x 1.0 grade 12.9 IMO that seems almost too hard and is making them brittle anyone else ever break these bolts? I'm considering changing them to a grade 10 Allen bolt or maybe even a grade 8... thoughts? Or is this a fluke incident?

 

Bolt grade is for tensile strength. Higher grade will be more brittle. Yeah a lower grade will bend more. The big problem is why your bolts were taking a shear load in the first place?I only guess shearing since I can't imagine them breaking any other way? Too strong to stretch and snap?

 

Ya that's kinda what I thought as well.. It def wasn't loose and they were loctite in place.. I did think it was strange.. They were grade 12.9 but I drilled through them quite easy I felt. Wonder if it was just a bad batch of bolts idk.

 

Bolts are a m10x1.0x25 grade 12.9 I'm having a problem finding them local Fastenal can get them in two days at 2$ a bolt I was gonna replace all of them (12) allens cap screws are not made in this thread pitch so that possibility is out.. I put a call into arp and they may have something idk waiting on a call back