Hi guys, I was wondering if precautions should be taken when unbolting the u bolts to drop an axel, when the history of the spring packs are unknown. My thought is, what if the center bolt on the springs is rusty etc., how much energy is stored in the packs? Thanks

 

Always a good idea to put a C clamp or 2 near the center just in case. I have cut rusty U bolts and had them pop, there is surely some energy there...

 

Depending on how worn the spring is, there can be a massive amount. Wear glasses incase it pops and rust goes flying everywhere. As stated, use 2 C-clamps. Use large clamps because they will hold better and give you enough room to release the tension once you unbolt the pack

 

Really on these type springs, there is not much energy stored in a spring that is removed. The energy is stored when the spring is under load, be it an empty vehicle or a loaded truck. When I tore down the springs on my F4, a couple of the center bolts were broken and the others were bent. The springs that had the broken center bolts kinda fell apart when the U bolts were removed. Nothing spectacular. A couple well placed clamps will contain any stored energy. The springs should be respected for what they are but nothing to be overly concern about. Certain design springs such as early Ford transverse springs have a lot more energy stored if I remember right. It has been years since I had one of them apart. Consider too, any spring pack may have been modified at one time with extra arch leaves installed which would make for more stored energy in a static spring pack.
As with any parts about these old trucks, treat them with respect, many of them can hurt you.
Good point, Jimmy.

 

Thank you all for responding. When I don't know for sure, I ask. Safety first ya know.

 

In a new spring pack, each successive leaf below the main is curved to a slightly smaller radius curve, so the ends of the leaf touch before the center, when the space between the leaf centers is compressed together by the centerbolt, there is tension in the pack that will want to relax if/when the centerbolt is removed. The amount of tension/energy depends on the number and thickness of the leafs, the difference in the curve, the age of the spring, etc. I have seen springs that had enough tension that they could do significant damage to any body part in the way. Others may have been overloaded or sat long enough that the leaf ends didn't even touch the leaf above, or they curve in a reverse arc. This design of a leaf spring pack is what gives them their progressive spring rate that you don't get with other type springs, coils, monoleaf, etc.