Hey all, back again. Almost done with the motor. Broke my first bolt today on it.
I found a factory is300 manual and am confused on the torque spec needed for the motor mount bracket that attaches to the block.
book read it was 44ft-lbs and I just snapped the bolt.
anyone know if this spec if correct and I had a weak bolt? If not what’s the correct spec?
also anyone know what bolt it is as well? Can’t find much discussing the bolts themselves only the monts And using the different trd ones for the supra but I’m not interested in that.
I need the torque spec and the bolt size/thread pattern please
I have more bolts and can hit up Home Depot as they have the best bolt selection around besides where I work but it’s closed for the weekend now and I’d rather buy them.
the bolts on my 5.9 Cummins 12v were grade 8, I can’t tell the grade on these. Has anyone upgraded them to grade8 so it’s safer to run more power? My Cummins broke the grade 8s and I went to 10.9’s
thanks in advance.
photo below for reference.
Assuming you did, maybe someone over torqued them at some point? Or your wrench could be off. I used a digital gauge alongside my click type wrench just to make sure. (And also because my smaller torque wrench is 20ft-lbs low because the handle got misaligned somehow.)
There are no grade 8 bolts anywhere on the car. That would mean imperial threads. Either grade 10.9 or 12.9 will work. m10x1.25 would be my guess from brief searching. you have the bolt. Just measure it. It’s either 10mm or 12mm.
The thread pitch is almost certainly fine (1.25 either way I think) so you might not find it in Home Depot. Ace hardware has AMAZING metric hardware section if you have one of those. Fastenal, despite its name, does not. McMaster Carrt has amazing hardware section as well but they’re “online” only. (Though I live close enough to do warehouse pickup)