Hi, lowering the stang today, did you guys that lowered your car replace the bolts and nuts? I seen in the service manual that ford says to replace em. Thanks
The factory bolts are ''torque to yield'' which means replace them. I've had mine off several times and reused them. I just put a little loc-tite on them and don't crank them down too hard.
Thanks for the input fellas, I got the new springs, struts, shocks, strut plates, and panhard bar in. Went alot easier than I thought it would. Wow what a difference in handling!! Put the D-specs at full hard to see what it was like, and man this thing can take some corners now! Still need to adjust the panhard bar yet, will do it tomorrow... And of course go find some twisties up in the mountains. I ended up reusing the nuts and bolts, will keep an eye on em though. Might end up replacing em just to be safe. Thanks for the help guys!
BTW what does "torque yield" mean exactly?[/QUOTE]
It means that the bolt is stressed or torqued into the plastic range of the metal. It is slightly stretched beyond the elastic limit, and does not return to the original length.
The danger of re-using the bolt is that it has been stretched once, and each time it is re-torqued it is stretched a little more until it reaches its maximum plastic limit and breaks. There is no way to tell how far into the plastic range the bolt has been stressed, and how much more room there is without knowing the original length into several decimal places, and knowing the ultimate elastic limit of the particular metal batch.
You are probably safe to use one-time bolts for a second torque, but I would not use them a third time, as there would not be much, if any, safety factor left.
Torque to yield bolts are bolts that can only be torqued to the specific amount once. This is because they are allowed to stretch for extra holding capacity. Think of them as a rubber band. When you put a rubber band around something it has to be tight and stretched to work right. The only thing is, when your doing this with metal fasteners it can only happen once if you want to keep the same amount of force applied.
The nuts on your front sway bar end links NEED to be replaced, they are one-time use only by design and will not hold their torque a second time even thought they are not TTY design. If you don't they WILL come loose on you. Mine would not stay tight nor would the ones on my friends car. I ended up buying some Nylock nuts the correct diameter and pitch to replace my end link nuts.