JFS2295
Silver Member
Re: Lug nut torquing
Just make sure your husband or any operator knows of the situation.
We used to deal with lug nut and stretching issues in our work. If the bolt/stud is over torqued there tends to be a reduction in diameter below the engaged threads from the stretching of the bolt or stud. Also stress risers can form at the root of the thread which can propagate later in use, allowing the bolt/stud to shear off. The good thing with a tractor is the bolts/nuts are exposed you would can see when any fail, and it's usually a situation where they don't all fail at the same time. As long as the operator does a daily, or maybe something like every 4 hours of use, look to see if there is one missing, life should be good without replacing the fasteners. For our test work, if there was a mistake we would just replace all immediately. You don't have to do that as I doubt the tractor will be going 100mph at GVW and stopping in the shortest distance.
As far as lubrication on the threads, while it might help reduce the issue of fastener corrosion static torque issues, oiled threads develop higher bolt/stud tension then dry threads when fastening torque is used as the guide. If we were tightening and measuring the bolt length (stretch), then oiled threads would not matter. But we are inferring stretch from fastener torque.
With an over torque if there is any damage, it's done. Correcting to the proper torque is the right thing to do, but observation of the fasteners is the future course of action.
Just make sure your husband or any operator knows of the situation.
We used to deal with lug nut and stretching issues in our work. If the bolt/stud is over torqued there tends to be a reduction in diameter below the engaged threads from the stretching of the bolt or stud. Also stress risers can form at the root of the thread which can propagate later in use, allowing the bolt/stud to shear off. The good thing with a tractor is the bolts/nuts are exposed you would can see when any fail, and it's usually a situation where they don't all fail at the same time. As long as the operator does a daily, or maybe something like every 4 hours of use, look to see if there is one missing, life should be good without replacing the fasteners. For our test work, if there was a mistake we would just replace all immediately. You don't have to do that as I doubt the tractor will be going 100mph at GVW and stopping in the shortest distance.
As far as lubrication on the threads, while it might help reduce the issue of fastener corrosion static torque issues, oiled threads develop higher bolt/stud tension then dry threads when fastening torque is used as the guide. If we were tightening and measuring the bolt length (stretch), then oiled threads would not matter. But we are inferring stretch from fastener torque.
With an over torque if there is any damage, it's done. Correcting to the proper torque is the right thing to do, but observation of the fasteners is the future course of action.
