F-12 Power Lift Seat Spring

DC Snider

Member
Currently in the process of restoring my F-12, which is equipped with the power lift unit beneath the seat. I noticed when I bought the tractor the seat sit noticeably off to one side, like it was twisted. In putting it back together I've determine the long leaf type seat spring is bent. I guess the man that occupied the seat for years before me was a tad on the heavy side and over time it just tweaked the spring. It needs to be bent about 1/2" back toward the centerline of the tractor. Wondering if heating and quenching in oil would be sufficient? I don't want to risk breaking the spring later, but it is just gonna be a show tractor, and I weigh only about 180 so it's not gonna be under a lot of stress. incidentally the short inner spring appears to be fine, it's just the long one that appears to be bent. I'd appreciate any input or suggestions...
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I wouldn't heat it. If you can clamp the large leaf in a rugged vise and determine exactly where the bend is you may be able to straighten it by twisting with a long pipe wrench or better a large adjustable crescent wrench. I have a 20 inch crescent which I put a piece of pipe on for more leverage. It works well for straightening things.
 
Well the picture don't show it and unless you sit on the tractor you probably couldn't tell it. With just the spring laying in the floor on it's side you can see it's about a 1/2". Thought about just leaving it, but it would just bug the snot of me.

I had not considered bending it cold. I may try to take it to the shop at work, put it in a large vise and try to twist it cold.
 
Reminds me of a VW beetle I bought in high school. An older couple had it. They were a true Jack Sprat and his wife. I had to reset the tortion bars as the passenger side sat about two inches lower.
 
I work at a prestress/precast concrete plant. I'm gonna take it over to the precast plant in the morning and lay it in the floor and add a 4,000# concrete block on top of it...that should do it. If not, we make stuff that's a whole lot heavier.
 
As has been already stated, don't heat it. Spring steel is a hardenable type of carbon steel that is formed cold. The cold forming, winding if coil, bending in a jig if a leaf, introduces stresses in the steel that give it "memory" when it is later flexed. It wants to go back to the original shape it was formed into. Heating a spring relieves those stresses, basically annealing (making soft) the metal. The result would be that the spring will bend at the annealed point, and stay bent.

Be careful about bending that spring. Applying too much force can break it, as there is a certain amount of brittleness in all springs. Too, the older and more used a spring is, they tend to do one of two things: either get soft (heat from flexing over time anneals them), or the metal fractures.
 
It was mine, before I did any such drastic thing. I'd just put some galvanized washers under the seat, shim it up to level, tighten her down and call it good.
 

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