lowering the back by heating

[piecesparts]

DON'T you dare heat the springs and then come onto the roads that I am driving on. I don't want to be your victim. Buy a set of shackles and do it right. The price is small and you will enjoy the ride much better going down the highway and not running down into the ditch. Those using a torch on springs is destined for a hard life later.

[jermasaurus]

Alright, He's probably heard enough- And it was only and idea. Ironicly, people told me to do the exact same thing but I never actually considered it.

[boxrodz]

Originally Posted by pissonNOS

what i dont understand is they say heating is not good for ur springs? why is it ok to powder coat your leafsprings then?

Like 1FAAST and N2 said, heating just a portion of a leaf spring to deform it will cause it to be hard and brittle in that area. However, each leaf of the spring can be fully heated to reshape them. The leaf is heated until it is red-hot (>1600* F) to erase its' memory, reshaped and then quickly cooled. Each leaf is then heated again to about 1000* F for a period of time to remove the brittleness created during the first heating and cooling process. This gives the leaf a 'new' memory. You end up with a re-arched leaf spring. Of course, most shops just used a press to re-arch a spring. Re-arching was one way to lower (or raise) a ride.
BTW, chroming a leaf pack is also frowned upon.

[69moneypit]

Threee years ago when I took my truck to deep south Springs to be lowered. I asked them to heat my front springs and they refused to . they lowered the front by cutting a coil out. i was told you never know when the spring is going to break after being heated. The owner told me about a guy whose front ( heated) coil broke in a banked curve and caused him to hit another car head on at 60mph. I was really thankful I did not go that route because i would not want to hurt someone or cause myself to be hurt.

[boxrodz]

Originally Posted by 69moneypit

Threee years ago when I took my truck to deep south Springs to be lowered. I asked them to heat my front springs and they refused to . they lowered the front by cutting a coil out. i was told you never know when the spring is going to break after being heated. The owner told me about a guy whose front ( heated) coil broke in a banked curve and caused him to hit another car head on at 60mph. I was really thankful I did not go that route because i would not want to hurt someone or cause myself to be hurt.

Yeah, coil springs are a whole different ballgame. Re-arching only applies to leaf springs. Once a coil spring is again tempered or annealed, it is deemed useless. It's the reason why care is taken not to heat a spring when cutting a coil.

Unfortunately, you give a good example of what happens when suspension parts are incorrectly modified.

[short chevy]

When I said, I was going to heat the springs. I dint mean I was going to get the cutting torch out . I dont think they would break in less ,alot of wieght was put on the back. Ithink yall are over reacting. I been doing collision repair for25 years. when a truck frame is bent pretty bad we use heat when we pull it .I know a leaf spring and a frame are a little diffrent. i was just going to heat a little with a little heat . I was more concerned on how it was going to ride with heated springs not safety .and no I still havent did nothing to it.

[low 84]

definatly unsafe to heat them, but you guys are a little off on your heating analysis. heating and letting air cool (annealing) actualy relieves the residual stress in the spring and makes the steel softer and more ductile and malleable. thats why it drops the truck. to make the steel hard and brittle requires hardening, heating above a specific temp and quenching with water or oil. the fast cooling is what makes steel hard and brittle. so heating springs isn't going to make them brittle, its going to make them soft and able to deform which is definatly a bad idea

[low 84]

Originally Posted by short chevy

When I said, I was going to heat the springs. I dint mean I was going to get the cutting torch out . I dont think they would break in less ,alot of wieght was put on the back. Ithink yall are over reacting. I been doing collision repair for25 years. when a truck frame is bent pretty bad we use heat when we pull it .I know a leaf spring and a frame are a little diffrent. i was just going to heat a little with a little heat . I was more concerned on how it was going to ride with heated springs not safety .and no I still havent did nothing to it.

but how are you going to control how much you change the properties of the steel? when the springs were manufactured they were heated to a specific temperature, soaked at temp and cooled at a very specific rate to give them the properties they have. the temp you heat up to and the rate you cool at are essential to keeping the right properties for a spring. if you think you can just guess at it and end up with something safe and functional, go for it

[short chevy]

first off you never cool off metal like that, with water or air . That would make brittle like you say. What I was told by a old school is put weight in the back and heat about 2inches from the rear shackle on the top leaf spring,with the jack under bed. He said it wouldnt take much heat and do one at a time, and let cool by it self . Have yall ever tried to break quarter inch steel after its been heated ? dont think its going to happen. The springs dont have that much weight on them.

[1FaastC10]

be prepared for a high speed entrance into the ditch. either your truck will put you there, or someone else who knows what kind of hillbilly crap you've done to your truck will.

as i said before, stop being cheap, and do it right. lowering incorrectly by removing leaf springs, cutting coils, etc is bad enough. but to knowingly heat a leaf spring, knowing the damage it will eventually do, is just crazy. buy a set of shackles, they're like $40.

[low 84]

Originally Posted by short chevy

first off you never cool off metal like that, with water or air . That would make brittle like you say.

lol, that statement couldn't be further from the truth. have you ever heard of hardened steel? how do you think they harden it? hardening is the process of heating and queching. quenching is cooling the steel. and its done using air, water and oil. the hardness you acheive has do do with the iron content and alloying elements and how you quench it. believe what you want but that is how you get strenth from steel. you just have to balance the amount of hardess you want with the amount of toughness you want. i never said they would break. what you are doing by heating and letteing air cool is annealing. and that will actualy make it softer so its more resistant to breaking but less resistant to deforming. this all comes from engineering materials courses which i have taken and harneding and annealing i've done myself, in labs. if you really want to understand i can break it down to a molecular level too or you can just take out your tourch and heat away

[short chevy]

like I said. If you cool that kind of metal off with water or somthing. It will make were it will break easer. Dont know all the scientfic part of it., hell I cant even spell it, but i do know that if they were heated with low heat and cool off without any thing they would not break inless you had abunch of weight on them

[1FaastC10]

Originally Posted by short chevy

I been doing collision repair for25 years.

stick to that...

[8t5Silverado]

Originally Posted by short chevy

like I said. If you cool that kind of metal off with water or somthing. It will make were it will break easer. Dont know all the scientfic part of it., hell I cant even spell it, but i do know that if they were heated with low heat and cool off without any thing they would not break inless you had abunch of weight on them

Or fatigue them to failure. low84 is right.

Yes people used to place jacks or 2x4's under their vehicle and then heat their springs to lower them...not a good idea. Just because it was done back in the day doesn't mean it is a good idea.

Not to be a know-it-all, but I do understand the "scientific part of it," having learned it in Metallurgy 221.

http://www.efunda.com/processes/heat.../annealing.cfm

It basically comes down to: It's not worth the risk, to you and to everyone else on the road.

[Grande Rojo]

these spring were on a truck I got last year!!!!

I sold it

http://67-72chevytrucks.com/vboard/s....php3?t=130351

[boxrodz]

Originally Posted by short chevy

. . . Im going to build my own brackets. I found some thick channel in the garage last nite. Ill let yall know how it turns out.

Short Chevy - How's your flip brackets coming along?