Over torqued bolts
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Joined: Mar 2004
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Over torqued bolts
I need advice from an experienced mechanic.
I have a '92 F250HD 4WD with a Dana 50 IFS front end. I mistakenly over-torqued all of the bolts that attach the two brackets holding the inboard ends of the IFS arms to the frame. These are not the bolt on which the arms pivot.
The spec called for a max of 110lbs and I torqued them to 145lbs. The bolts are 9/16 at the shank and the thread is 1/2 inch. I have not backed them off since torquing them down.
I am concerned that the bolts have been stressed and may fail. Should I replace the bolts or are they OK?
I have a '92 F250HD 4WD with a Dana 50 IFS front end. I mistakenly over-torqued all of the bolts that attach the two brackets holding the inboard ends of the IFS arms to the frame. These are not the bolt on which the arms pivot.
The spec called for a max of 110lbs and I torqued them to 145lbs. The bolts are 9/16 at the shank and the thread is 1/2 inch. I have not backed them off since torquing them down.
I am concerned that the bolts have been stressed and may fail. Should I replace the bolts or are they OK?
Last edited by Schmavic; Mar 12, 2004 at 07:29 PM.
Post Fiend
Joined: Jun 2002
Posts: 13,873
Likes: 3
From: Atlanta GA
For a 1/2 inch grade 5, that would be a bit much, for a grade 8 it would be at the upper limits, but, okay. If I was worried about it, next time the bolts were out, I would throw them away and put new ones in.
For now, I would just leave them be unless there was a failure. Most likely nothing will happen for the next twenty years if nothing happens in a month of driving. A lot of the "90-110" specs for 1/2 inch bolts applies to to making sure the bracket is tight enough without destroying the bolt or bracket for future use once it is removed.
Backing them out now, would not solve a thing. The bolts have already been stretched towards their yield point. All you will have if you back them out is a weakened bolt that might fail the next time you tighten it down.
I would say you are good to go. When you take the bolts out the next time, look at the threads to see if they have been squished up, sort of like the tops and bottoms of the threads are moved, if not, I would reuse the bolts BUT torque them back down at 145 again!
For now, I would just leave them be unless there was a failure. Most likely nothing will happen for the next twenty years if nothing happens in a month of driving. A lot of the "90-110" specs for 1/2 inch bolts applies to to making sure the bracket is tight enough without destroying the bolt or bracket for future use once it is removed.
Backing them out now, would not solve a thing. The bolts have already been stretched towards their yield point. All you will have if you back them out is a weakened bolt that might fail the next time you tighten it down.
I would say you are good to go. When you take the bolts out the next time, look at the threads to see if they have been squished up, sort of like the tops and bottoms of the threads are moved, if not, I would reuse the bolts BUT torque them back down at 145 again!
