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Author Topic:   LEAF SPRINGS
redneck racing
Dirt Forum Champ
Total posts: 860
posted September 14, 2004 07:26 PM  
I was just wondering how you get the Labrum springs apart to grease them. Do you cut the keepers completely off or just heat up the folds and bend them up. Thanks Eddie

JohnG
Dirt Maniac

Total posts: 137
posted September 14, 2004 09:15 PM  
I think greasing them is old school.

They build leafs with nylon blocks in them so you dont have to grease them..


juliaferrell
Dirt Freak

Total posts: 370
posted September 14, 2004 09:25 PM  
I hate to break your heart but "DON'T GREASE or OIL a LEAF SPRING!!! This soaks into the metal and weakens them!!!! Takes the temper away!!!!!! This old school mentality doesn't work with modern "no heat" style spring steel. Get you some "squeaker pads" from your local spring shop. You can drill a 3/8 hole in the end of the leaf if yours isn't already and "snap in" some D pads as they are called in the spring business. They are the little plastic *urethane based* pads that springs use to control noise. You can also get the corvette spring lining material in the 2 1/2 inch width and line in between the leaves. This is also cheap material that most old traditional spring shops normally have lying around. Why do you think your springs aren't working properly?? or binding?

mechanist
Dirt Full Roller

Total posts: 33
posted September 15, 2004 01:23 AM  
Sorry to differ JF, but oil does not soak into metal and weaken, or change the hardness or properties of the metal in any way. The definition of temper is "to soften", so in tempering iron, you are softening it from a hardened state. You can make it softer by heating it, to reduce hardness, or by definition "temper the steel". This is what some guys do to coil springs in thunder stock where they are required to keep the stock coil springs, and want to drop ride height and raise the spring rate at the same time- they heat a portion of the spring to render it a non-spring at that point because the hardness has been effectively reduced, or tempered by heating. Speaking of which, Eddie, you want to be careful about heating anything on a spring pack. Clips are usually pretty soft mild steel, and can be bent out of the way cold if needed.
The advice about the d pads is right, but whoever told you oil hurts spring steel is completely wrong. I would hazard a guess that those ideas came about as a result of observations of oiled versus non-oiled leaf spring packs... when the internal friction of the spring pack is reduced, spring rate will change dramatically.
think of it this way, your oil pan, valve springs, and transmission don't get softer from being continuously bathed in oil...

juliaferrell
Dirt Freak

Total posts: 370
posted September 15, 2004 02:53 PM  
Well dear sir...........a leaf spring contains raw carbonates, unlike a valve spring which has silicon carbonates. Here is a test for ya:

Take a spring leaf and soak it in oil....
Leave it there for sixty days.
Come back and arch it with your hammer.(Like I have for 20 years until they came out with hydraulic arching equipment) You will notice that your spring leaf has turned into mild steel!!!!))))))

I have been an engineer in the spring business all of my life...........I beg to differ with you on that one.......
If you have ever been around say an old Detroit powered truck or one with the power steering fluid leaking on the front springs you would more than likely notice that the truck has sagged on that corner or both corners.

juliaferrell
Dirt Freak

Total posts: 370
posted September 15, 2004 03:12 PM  
Yes I will agree with spring rate changes happening from the oiling. Especially the one that happens after a few dynamic cycles after the oil has reduced the elasticity of the steel.

I'm just stating a point here.....The tempering of raw spring stock is achieved by heating the raw spring stock and cooling through a designed process that allows for a harder metal to take on different shapes and remain ductile like. The older spring steels were very brittle after heating. Like welding on a 1/4 x 1 piece of flat steel in the same place til it almost melts and then wonder why it becomes so hard to drill and it breaks off very easily. Example: If you rolled the eyes on the ends of a leaf from repair plates *leaves produced in blanks to build and repair springs from" after heating and rolling you would have to dip the spring in whale oil and reheat evenly to approximately 1500 degrees to retemper the steel. If you didn't do this then it would just be brittle and you could physically break the thing off with a 2 pound hammer. The new steels tend to have better characteristics to heating but far worse characteristics to oil soaking. As you know, cast metals are brittle. These metals contain the highest amounts of carbons. The carbon content creates little pourous type "holes if you will" in the metal stock. Over time, these holes will become contaminated with oil and the carbon content will disappear........creating mild steel like properties..............

juliaferrell
Dirt Freak

Total posts: 370
posted September 15, 2004 03:20 PM  
http://metals.about.com/library/bldef-Spring-Steel.htm

There is a link for you to research.

redneck racing
Dirt Forum Champ
Total posts: 860
posted September 15, 2004 05:16 PM  
Great Info JF so the general consensus is to let them bad boys be, would wraping them up with duct tape help in anyway, that I would think would be a benefit to the springs in keeping the dirt out. Eddie

mechanist
Dirt Full Roller

Total posts: 33
posted September 16, 2004 01:00 AM  
I have never heard of this before JF. Not to say it is not true, but I do work an awful lot of metal, and a lot of it with a hammer. Well, I'll take that challenge. How new does the spring steel have to be (what qualifies as "the new spring steel") and what alloy, 1050, 5160? I'll plasma a leaf in half, soak one half, and in a coupla months, clamp an end in a vice, and weight it with ballast and record the deflection, then repeat with the other one. If what you state is fact, then the oil soaked one will probably bend. Somehow I doubt this...

By raw carbonates I assume you are referring to hypereutectiod steel? Under 0.83% the carbon is fuly dissolved, and there is spring steel under .83% carbon content, so there would be no oil soaking then, correct? So are you referring to just hypereutectoid steel as soaking up oil and reverting to mild steel?

Is the new spring steel air hardening?

I do have a few trucks. The front leaves sag on the side of the engine torque, opposite from the leaky power steering pump actually. the springs also have greasable shackles.

Come to think of it, I suppose the best stuff to use to lube your springs with would probably not be grease, but dry spray on molybdenum disulphide. It goes on like spray paint, but dries and provides lubrication. Moly is very slippery stuff. You should find it where you find metal lathe supplies. Some use it for lubricating lathe ways and gears. Works good in steering racks as well. Sure be a lot cleaner than messing with oiled spring packs anyway. Well... it is black, and sort of messy, so no free rides in that department, but it should work very well, and dust sticking to it would not be an issue.
-James

juliaferrell
Dirt Freak

Total posts: 370
posted September 16, 2004 01:41 PM  
either hypereutectoid or hypoeutectoid. Steel is either mild or casted. Casted contains the higher carbon contents. Tempering really can be done many different ways but the textbooks describe 2 basic ones: austempering, martempering. Without getting into great detail........lets say that the difference between the one and the other is the temp at which the items are quenched. austempering is the slow cooling from the 1600 degree melting point downward to reach the desired ductility.
Martempering is using a quench solution *oil* and then reheating to usually around 280 degrees for a period of time desired up to 24 hours or so. Some people use different techniques.
This difference is where the oil soaking comes into play. Oil soaking along with cycling and fatigue *I pointed out that simply soaking would do it on most common everyday pieces of spring steel* of the leaf creates the physical properties of the tempering "for simple terms" to errode. The items with higher carbon content will erode faster ***hypo verses hyper"

Since you didn't agree with the old Detroit or powersteering leak theory which powersteering leaks are usually on the driverside the same as the torque effects *engines running Counter Clockwise as your setting in the Drivers seat* Just pay close attention over a period of time to the sagging corners on vehicles......most of them will be soaked with oil....some will be loaded heavier on those corners in proportion............and some will have cobbled up spring work that doesn't promote levelness......LOL

If you would like to be technical about the test......normal ole broke leaf *usually out of a ford F150......place in your press..........measure the pressure point to bend.......with a 3" .323 thick leaf *as 4x4 f150's have til new body style* with a 11" spread between your arching madrel and a 1 1/4" round stock pressing. It would take roughly 1900 psi to bend. After oil soaking for 60 days,,,,it will take 1450 psi to bend.............that is typical of OEM spring steel...........alot less with the licorice stuff that is being produced from Thailand, China, ect........these steels are nearly mild right off the rack.........The longer you soak,,,,,,,,,the less psi it will take......................

mechanist
Dirt Full Roller

Total posts: 33
posted September 16, 2004 11:14 PM  
I'm curious now, I'll try that.

"alot less with the licorice stuff that is being produced from Thailand, China, ect"

LOL!!!

yeah, that's for sure. I used some carbide the other day that appeared soft in use. Not exactly what you look for in a tool bit, but under magnification the edge was flaking under load. Good for wood turning maybe, sure not for cold rolled. Good thing it was on sale, as it's being returned to China via the s**** bin...

Enjoying the steel prices lately? oi.

-James

Ego Racing
Dirt Forum Champ
Total posts: 724
posted September 17, 2004 12:13 PM  
quote:
Originally posted by mechanist:
Sorry to differ JF, but oil does not soak into metal and weaken, or change the hardness or properties of the metal in any way. The definition of temper is "to soften", so in tempering iron, you are softening it from a hardened state. You can make it softer by heating it, to reduce hardness, or by definition "temper the steel". This is what some guys do to coil springs in thunder stock where they are required to keep the stock coil springs, and want to drop ride height and raise the spring rate at the same time- they heat a portion of the spring to render it a non-spring at that point because the hardness has been effectively reduced, or tempered by heating. Speaking of which, Eddie, you want to be careful about heating anything on a spring pack. Clips are usually pretty soft mild steel, and can be bent out of the way cold if needed.
The advice about the d pads is right, but whoever told you oil hurts spring steel is completely wrong. I would hazard a guess that those ideas came about as a result of observations of oiled versus non-oiled leaf spring packs... when the internal friction of the spring pack is reduced, spring rate will change dramatically.
think of it this way, your oil pan, valve springs, and transmission don't get softer from being continuously bathed in oil...

To temper: To harder metal. Tempered steel has been hardened.
To temper any metal is to alighn the crystaline structure to make it harder, That is why when you weld chrome moly the metal breaks by the weld (it cracks because the heat and cold boundry created a hardened area) if after you weld it you heat it evenly with a flame and allow it to cool it will not crack the steel.
The oil used in tempering is due to the fact it conducts heat better than water as it will not boil away. You can also heat different oils hotter than others. As was stated here the heated items a quenched in an oil bath and reheated, the reheating taking place is in the oil bath and as you know you cannot get water to 280 degrees.
Anneling is when a metal is heated and quickly quenched in a cooling media, typicaly water, to soften a work hardened metal.
If oil softened steel all of our military weapons that are antiques would fall apart as they were oiled down and stored for MANY MANY years and were always oiled in the feild during use. Antique cars crankshafts, blocks and rods would be junk as they would be to soft to use.
But dont we want older blocks because they are stronger?
The old truck that is broken down and oil covered is from lack of maintence not oil.
Oil stops corrosion and reduces friction if it soaked into steel then when you cut it with a torch she steel would ignite and burb until the oil was gone.

juliaferrell
Dirt Freak

Total posts: 370
posted September 17, 2004 09:36 PM  

Ego: I will respond to your question like this..........How it is very hard to understand this stuff.........metal is a very complex issue.........tempering is a very complex issue..........just search martensitic on your search bar...........

Now I will try to simplify things a little bit.

1) spring steel *automotive* is created by a martensitic shadowing process.

2) the other metals you spoke of: crank: blocks: oil pans ect..... are of a whole different animal know as "pearlitic"

*example: if you would cut a 3" wide 1/4" thick and 24" long piece out of your engine block it would not be ductile like and have elasticity like spring steel* Do we agree on this?

And I'm sure that mild steel oil pan wouldn't do it either.............ok?

*****What is harder to drill........spring steel or crankshaft, engine blocks and oil pans........ok? Are we seeing something here that might determine a difference in characteristics?

Yes tempering aligns alot of things microscopically and structurally, I will agree with you there......

Think of it this way........hotter harder.....cooler.........softer. And this is very hard to understand!!!!!! Cause you think of melting........right? well get a piece of steel at just under it's molten state and dry to drill it with anything!!!?? Are we doing ok?

Now as far as petroleum distillates and its relationship to the martensitic shadowing:

We all agree that heat removes impurities from metal.

Of these impurities like sulphur ect.......we have something created from this burning known as carbon........When oil is heated does it not create carbon?

So my point is this: When dynamic energy creates heat *like how a shock, tire, or anything that cycles dynamically creates heat* the martensitic shadowing is simulated during dynamic cycles......when oil is installed into that process you have a very small version of this shadowing taking place.........overtime there you go...........The more the spring is cycled the more the original shadowing will erode and the weaker it will become?

Notice I told Mechenist that just setting it in oil would work..........with these new style steels they get real productive on this stuff and it doesn't take near as well. This not taking of china, brazilian, pakistani, thailand, ect........is due to the alloys they use to create tonage......these alloys have big big adversities to oils. Have you tried welding contaminated aluminum or pop metal? Hard to get clean isn't it? The oil just penetrates right on in.........HEHEHE

*kinda like trying to paint a car that has been baby oiled* You try everything you know to get it off so it takes paint but no matter what you do the paint just rolls right off...........

I know that there are alot of things scientifically that weren't addressed in this discussion.......because frankly,,,,,,,I'm not a good explainer and alot of this stuff is way over my head.....

Hope that helps.


The microstructure (tempered martensite or bainite) produced by quenching and tempering these alloy steels is characterized by a greater toughness or capacity to deform without rupture at any strength level. Similarly, under the adverse state of stress below a notch in bending, the tempered martensite may flow considerably at a testing temperature far below that at which a pearlitic steel of equal strength would break in a brittle manner; the Charpy or Izod values are thus improved. The basic phenomenon of developing this favorable microstructure by heat treatment is manifested in plain carbon steels, but only in small sections; thus the most important effect of the alloying elements in these steels is to permit the attainment of this microstructure, and the accompanying superior toughness in larger sections.


Ego Racing
Dirt Forum Champ
Total posts: 724
posted September 18, 2004 12:25 AM  
Then with your theory valve springs would fail all of the time from the oil bath not from mileage or usage, they are made of spring steel and are in a constant oil bath, more than any suspension leaf or coil spring would ever be exposed to, yet a have a motor in my truck that has 171,000 miles on it and it is 8 years old and the springs were just tested when I replaced cams and they are within 1-2% of there original seat and opne pressure.
The heat cycling on a chassis spring will never reach the temprature needed to start a cyclic fatigue problem. In all of your post you noted temps over 200 degrees, after a race check you springs and see how hot they are.
As noted in the above posts the weapons have many many parts that are spring steel and they are in a constatn oil bath and they do get hot during use, much hotter than any chasis spring.

Ego Racing
Dirt Forum Champ
Total posts: 724
posted September 18, 2004 12:47 AM  
One last thought: If this were true I could go buy a NEW spring and have it rated then soak it in oil for a period of time and when I rated it again it would be softer. NEVER HAPPEN, the oil would have to have complete permeation of the steel to change the properties not just on the surface or the tens of hundereds of thousandths of an inch it could make it into.
The steels used for spring making depend on the application and type of spring. They range from plain carbon grades in the range 0.5% to 1.00% C. to Chromium, Chromium-Vanadium, Nickel-Chromium-Molybdenum, Silico- Manganese and Silicon-Manganese-Chromium-Molybdenum types.
So you see there are different steels and they are used by different MFGs. for the same purposes.

mechanist
Dirt Full Roller

Total posts: 33
posted September 18, 2004 02:07 AM  
Ego, just a note. You have it backwards, which admittedly is the common usage of the word temper, but it is backwards nonetheless.
To temper steel is to soften it.
Now hold the phone, read on... The process of tempering begins with heating the metal to a hot state, usually red, then quenching it, or cooling it. The speed you cool it at defines just how hard it gets. Molecularly, you are getting the most random association when it's cooled the quickest, ie the finest grain, and the most brittle state the metal can be in , dependent on the alloy. Quenching speed is controlled by what you use, (oil, air, water, saltwater) and agitation of the solution.

Now that the steel is hard, you need to soften the metal to a point where you can use it without it breaking, or shattering. Let's use a cold chisel for example. After heating to a red heat, or a normalizing heat (where the iron molecules are free to move, and the steel becomes non-magnetic) and quenching quickly in water, the chisel end is now brittle hard. If you were to use it on that nut that is seized on the bumper bolt you are trying to free, the chisel end would fracture and is useless. So to change this, we now need to reheat the chisel end, so it softens to the point where we want it. If you clean the chisel end well with an abrasive, you will see oxidation colors of steel happen... the shiny steel gets a light straw color, then darker, then blue and purple. This represents temperature changes from approx 440F (straw) to 520F (purple) The more you heat, the softer the steel gets, until it get back to it's softest state around 800F. What is happening is the carbon atoms that moved into the center of the steel crystal while it was at the normalizing heat, moves back out on reheat, and softens the steel. More heat equals more carbon movement, and softer steel. For a cold chisel, you would stop around a dark straw color, then immediately cool the chisel again.
To purposely soften (anneal) steel, you need to heat it to the normalizing point of non-magnetism, then cool it slowly. Like wrap it in fibreglass insulation and leave it for a day. When you check it after, the steel wil be at it's softest anealed state.

This holds true for all ferrous metals, but non-ferrous are exactly the opposite. Copper is annealed by fast quenching from a red heat, and hardened by slow cooling.

HTH
-James

redneck racing
Dirt Forum Champ
Total posts: 860
posted September 19, 2004 07:38 AM  
Decided to just tape the springs and call it good. Eddie

juliaferrell
Dirt Freak

Total posts: 370
posted September 19, 2004 08:50 PM  
We could talk this subject into the ground...........as we probably have already. Just don't wrap the springs up tight. Thanks mechanist. Hopefully someday someone will see this information and say:

"What the **** were these guys talking about?"

And yes if you soaked that spring in oil for a period of time it would last far less than one unsoaked.

Why? Simple terms? oil and spring steel don't mix well.

Valve springs and leaf springs are two different animals.

You can oil yours but I will continue to keep mine oil free.

cobb
Dirt Maniac

Total posts: 131
posted September 21, 2004 06:17 PM  
yall confused me...... which way do i turn at the end of the strightaway again?

stormy
Dirt Full Roller

Total posts: 49
posted September 22, 2004 12:00 PM  
Left....but ONLY if ur crystals are aligned in ur oil pan see? wait no..right...no...left (i think) LOL redneck racing- looks like a good time to duck out tha door on this one huh

    

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