Farmall Cub

I put in a new differential seal tonight. I was going to torque the retainer bolts b/c I had loosened them. The bolts just kept tightening and I had the wrench set for 45 lbs.
I felt one bolt go and was able to get it back out. Is there anything special about the bolts? Grade 5? Maybe I need to get a smaller torque wrench.

Grade 8 ONLY at 45 ft-lbs. I had to double check that spec. Have you used this wrench before? What type is it?

Not the first person here recently that's stripped bolts. IH had torque specs that were, in my opinion, a little on the aggressive side. 45 ft-lbs on a 3/8 bolt is really pushing the limits. I back them down to the GM standard for a 3/8 grade 8 bolt and torque them at 40 ft-lbs. The little bit of clamp that you lose won't hurt anything but the time you save repairing threads is worth it.

As far as the original question - if you are buying replacement bolts - grade 8 is the way to go.
Yes - would be a good idea to get a reference check on your torque wrench - you may just be reading the vernier incorrectly and have the wrench at 55 instead of 45.....