The Stovebolt Site Forums The Shop Area Engine Shop any experienced metalurgist on board?

could use some advice on heat range used for dropping AD axle (54') looks like were gonna go 2 1/2" with either a few leafs removed or reverse the spring eye. FEEDBACK PLEASE!

Are you heating and bending/ stretching?
Or cutting and welding?

I have cut and welded 2 axles, with over 10,000 miles on each, still used as trucks hauling stuff, and no signs of trouble.

Check the picture link below, and the ford axle folder for the most recent info.

Grigg

Just one mans opinion, but heating, bending, welding on stering components is an abloslute NO in my book. Ride at your own risk if you do this.
This is one operation that requires professional experiance and facilities.
And before ya jump on me Grigg, this is just my belief and your intitled to yours.
Denny Graham
Sandwich, IL

Metal changes in strength when heated and cooled in different manners.

If you heat and cool metals, the properties of the metal change in hardness and strength.

How high of temp is it brought to and how is it cooled? You most likely want the complete piece to be heated and cooled to the same temp and rate for consistancy. Different methods of cooling are air cooling, oil quenching, water quenching. There are so many factors with metals, it would be hard to tell what you have metalurgically when you are done unless you really know what you are doing.

That being said, I know that these modifications have been done for years and many with no ill effects. But rest assured, I would be willing to bet that there are many failures and near failures out there because of it.

When doing this type of modifications, you are "at your own risk".

Denny,
No need to get defensive, I happen to agree with you for the most part.

I would be very leery about modifying an axle to "drop" it. I too agree that the strength of the axle could, and probably will change. I was secretly hoping that we would talk him out of trying to modify an axle like this.

You say, "how can you say all that when you just posted some ideas on how to do it?"

I think it better to let someone learn from what I did succesfully then let them learn on their own with trial and error, as the error part could be deadly.

I used axles that were rated for around twice the weight of the original axle. I asked around to see if what I wanted to do had been done, and with what results. I also found out how to do it "properly", but knowing there is still a risk. I cut and welded them in the center. If they fail then the center will bow downwards. So, considering the extra strength, and the possible failure mode I decided it was a risk I was willing to take.

I did talk to the people at MorDrop? and they apparently do this for a living. I have also heard that some of the work they do is not very good, and some is.

So, axles can be modified, it is generally not a good idea, often against the law, and hard to find reliable information on how to do it properly and "safely".

Grigg

Read any old shop manual and they show big presses and jacks used for axle alignment. I am betting a axle will take way more then you think it will. Joe

I cut & welded the pitman arm on my Bonneville car yrs. ago. Then had it inspected by a shop that had FAA (aircraft) & USAC (Indy Car) inspection certification. Showed that inspection form to the B'ville folks, no problem. Later, on a street car, did the same with both sides steering arms. Also used to run Olds rear ends at B'ville & they had to be narrowed of couse to match the old car's track width. Which meant cutting, laying a weld build-up, & then machining splines in that to drive something that at full power would be losing traction & then hooking up as it went over wetter & drier salt areas. NO problem.
Go in a farm area & see guys fabricating trailer frames, implement pull bars, all kinds of stuff. Lots of it being pulled on public roads to get to the fields. The supply stores here sell stub spindle ends & you just weld them on whatever you're building.
I think with good welding practice & skills most any thing can be done.
Doug

Doug

The key is "with good welding practice and skills anything can be done".

Without those skills and practices......you die.


Sure, heating up steering arms and dropping axles have been done for years and years. Some fail, some don't.

I know my brother had a 39 Ford with a dropped axle. He bought some spindles with dropped arms on them and bolted them on the car. Ran it for a number of years, down the drags at 100 plus, not a problem. Then one day.......he just got back from a quick run down the freeway to a nearby town. He hauled ars back and as he pulled in the driveway he decided to go to the front of the shop instead and put it in reverse. As it started to go back and he turned the wheel, it spun in his hand! The steering arm that the drag link hooked to just snapped off!

Yep, without the good welding practices and skills........

Brian

The problem with heating steering components is that most of them are not made of mild steel but are alloyed to give them more strength. After the components are forged they are heat treated in a controlled environment to relieve the locked up stress. Once you apply heat to them you become the heat treat engineer and in all probability you have introduced new stress in the grain structure of the material. Granted, the part is not going to fall off the vehicle the minuet you let it down off the jack (in most cases) but you now have a part with an unpredictable fatigue life. The front end components are subject to a lot of load and cyclic vibration and this leads to failure by fatigue. Bump loads can reach well into the double digit "G" range at highway speeds. even driving out of you drive way you will encounter eight or ten G's. You might go a week or a month or maybe even years, you just don't know. It’s just my opinion but it's akin to playing Russian roulette when you’re in rush hour traffic at 50mph with one of these.
Mention of Magnaflux inspection was made earlier and this does show if there are any cracks present at the time of inspection. It however does not predict at what point the part is going to fatigue and fail. Generally a failure of this nature is rather abrupt because of the lack of proper stress relief, in other words the part just snaps off.
Denny Graham
Sandwich, IL

Three words - modulus of elasticity

Forged front straight axles are often cold bent slightly for wheel alignment,a degree or two.Back when ,the steering arms on old Fords were heated red and bent this way and that way to clear a lowered axle.I don't know anyone who crashed because of it,but I bet a few might have broken or bent.
Before you try this,and it should be a good experience if nothing else,that axle needs to be absolutely secure as in perfect level and bolted down.I suggest securing the axle to railroad tracks.It might be wise not to use rails that are frequented by locomotives.Then you need a jig of some sort to check the king pin position accurately before any heating.Once hot you want to bring the axle ends in as alignment as close as possible the first time.
It's easy to apply two torches,heat it red where the axle end curves upward bend itwith a huge pipe wrench to a predetermined point you figured out before hand on your "engineered" alighnment rig.Now heat the top near the kingpin eye ,bending it down to the original angle.A strong pipe through the king pin holes helps also.This will narrow the front track some,it may or may not suit your situation.
As for stretching the axle? Red hot in an oven,forged on an Iron Worker machine into the shape you want.

I wouldn't know a dropped axle if it came up and smacked me in the jibs, but I sure think this whole drill would be useless without some type of steam hammer or drop hammer or sumpin big and ugly to shape the axle and move the metal around to achieve the drop.

Stuart

10 micron, I trust you have seen the article on the HAMB about dropping a straight axle. If not take a look, here is the link.

http://www.jalopyjournal.com/forum/showthread.php?t=192953&highlight=dropped+axles

My advice though is to send it out to get stretched. There are several places doing this work. And they have the experience of many axles and from what I have seen do quality work.

As for all of the comments from those who are concerned for your "safety", I must voice my own thoughts on the subject of heating and bending and welding of suspension parts.

First off I try to respect a mans opinion, but sometimes it appears as though some are talking without any knowledge on the subject.

The art of customizing and hotrodding would not be what it is today if it were not for those who were not afraid of cutting and welding steel. Welding, if done properly is amazing stuff. I have cut, welded, fabracated, heated and bent more suspension parts than I can remember. Non of which have failed. I fabracated a disk brake conversion on a large 4x4 truck about 25 years ago. This truck was subjected to extreem off road use and in the end was in a bad road accident. None of the fabracated suspension parts failed or were even damaged.

I have cut and shortened several pitman arms on 4x4s. These were used in hard rock jeepin', and again no failures. To this day I would not be afraid to cut and weld suspension parts. That is because I feel I have a good working knowledge of how metal reacts to heat and welding, and how to control the stresses associated with these practices.

I commented a couple of weeks ago about someones rear axle spring mount welding. The welding was so full of slag inclusions a worm could find a home in the weld. The owner said the weld was ok, I would not ride around the block in the truck if I knew of the poor welding. I hope, for his loved ones sake that the welds are "just amazing" enough to keep the rearend where it belongs.

CV

Mid to late 1960s I learned to weld in HS and JC. The same JC that ran the welding training program for the local Naval ship yard.

1973-76 Started in the Steel industry in a black smith shop. We heated and bent more things than can be imagined. Forged and heat treated and normilized and just about everything you can think of.

76- early 80s Boilermaker apprentice and journeyman.

80-90s Fabricator.

I now just tinker with my 54.

The thing to remembere is qualified experience. I have seen many things on this and other forums that scared the beejabbers out of me. There are those with a Lincoln buz box that think they can weld anything that comes there way. Well there is a bid difference between farm welding and structural automotive fabrication and welding.

And yes, I have even cut and welded straight axles. It is all in the knowing how to prep. and weld and relieve the stress.

Enough said, if in doubt; let someone with more experience to it.

Lonnie

Lonnie,That's a great link.
Did anyone else notice that there was not one mention of the possible safety concerns with trying to drop an axle, must be a different bunch over there. Seems we are all concerned with the safety, what's wrong with us?

In that link is another link to what I think is a better jig and method, here is that link: http://www.jalopyjournal.com/forum/showthread.php?t=157006

Grigg

If you read the HAMB regularly you'll find some very safety conscious people there. It mostly comes out in discussions about trailering stuff and about brakes. I don't know why it doesn't show up in discussions of modifying axles like this.

And while I won't name names, I know at least three of the participants in this thread post there too....

There are a couple of places that offer new dropped axles and I've always thought that would be the best solution to this problem. I think CPP offers one and the price isn't much different than what I've seen charged to drop your stock axle.

I was not trying to offend anyone with the safety comment, just thought it was interesting, and almost funny.

here is my explanation of why we seem concerned with the safety of a dropped axle, and the other guys don't. I might not be right, but this is what I thought of.

The other guys accept dropped axles a viable option, they have heard about them and seen them a lot, and for a long time, with very few, if any, stores of failures. So it is a common and accepted practice to them.

On the other hand we over here at the Stovebolt are generally more traditional and not such radical hot roders, we therefore have less experience and familiarity with dropped axles. By nature when we don't know about something, or don't understand it, we just assume it's not safe, or it's a bad idea for the simple fact that we have not heard that much about it.

After reading the post on the other site, and looking at the pictures I am beginning to warm up to the idea of dropping axles.
Although still don't think they have a place on a working truck. But if it was a working truck you would not want the bumper dragging to start with, would you?

Grigg

If you aren't objectionable to a tubular drop axle, Classic Performance Products offers a 3" drop axle for $419.

Eli

The other one is 55 Dude, but he uses a different name here...

No offense taken Grigg, at least not by me...

Interestingly I had concerns about your welded axle when I first read about it, though after reading about what you did, noting you drive them a lot and haven't had any trouble, AND reading on the HAMB of others who have done it, I've come to believe it can be done safely.

My concern was at least in part my own unfamiliarity with the process, just as you suggest might be behind our concern here about dropped axles.

However, while I am unlikely to attempt either process, I think I'd be more likely to drop an axle than cut and weld one. I just don't trust my own welding quite that far.

Well Grigg, bout all out of wind out here, but I’m gonna just take one more swing at it. Of course you can encourage the younger inexperienced guys here to experiment and modify their front ends if you’ve a mind to but I’m for discouraging the practice unless, like I said earlier, you have the “proper facilities and experience behind you”.
Back in the 70’s and 80’s we had a family owned machine shop/welding fabrication business in which I ran the welding end of it. My bro and I were racing midgets and sprint cars at the time. He was twisting the wrenches most of the time and I was piloting. To help finance the racing we got into building suspension components, i.e., front axles, radius rods, drag link, tie rod, torsion bars, etc. which I built in the evenings. All of the welding was done with TIG. As Doug has been pointed out, the front axles had to pass Magneflux at the beginning if each season for circle track racing.
Since half of our business was machine work, jigs and fixtures were a natural for all the components we built. A trip to heat treat under the guidance of the metallurgist there pretty much guarantied a good part. Also part of the equation was baking to avoid Hydrogen imbrutement after plating with any of the parts. And no, we never had a failure with any of these “fabricated” parts in spite of the beating they got from the dirt tracks we ran them on. When you’re talking racing, anyone that straps themselves into a car is, or should be well aware that in this situation these cars are being pushed to their limit and that components fail at times. Every driver in the field is playing the same game, and that just goes with the territory. On the other hand, your family or the guy next to you on the freeway should not be presented those same odds.

Well, maybe just one more breath left in me, think I might just change my handle to WINDY! All that said, every factory manual that refers to solid axle alignment stresses NO heat and we have had numerous members who work in front end alignment shops post here that they also nixed the practice of re-heating an axle to bend it.
FIN!
Denny Graham
Sandwich, IL

wow! this is really interesting guys. safety is always my first concern. the reason i asked the question was having already consulted a couple local blacksmiths their general response was "can do" but their schedules won't allow the work to be performed until ????. after reading the article on the hamb i figured mmm! building a jig would be no problem at all so lets ask the "STOVEBOLT" guys to see what they thought i would get some very diverse opinions and i did. so has anyone here dropped a AD axle with positive results? thanks

My two cents! If you weld the axle, let it cool very slowly, in fact, insulate it and let it cool down as slowly as you can. You might consider preheating and slow cooling like you would welding cast iron. Welding brings the steel to the point where there is a crystal structure change and quenching it will leave it in a hardened state. The axle does not have sufficient carbon to be truly heat treatable but it can be effected to a lesser extent. Along the edges of the axle it will cool too quickly if you don't find a way to slow it down and the edges will become harder. This harder surface allows the creation of small cracks which become stress risers. Don't let the axle change temperature rapidly, let the structure normalize. No formal education in metalurgy but a background in materials. If you buzz box weld it, be sure to use low hydrogen rods.

I second what Rick says.

Here is the first picture in the sequence of welding an axle together, in the captions I explain a little about each step.

http://thumb9.webshots.net/t/59/459/8/12/49/2537812490080251109qAJiLJ_th.jpg

I covered the axle with a ceramic wool blanket when done post heating, it was still slightly warm the next day when I uncovered it. A big bucket of wood ashes is also a good insulator, and could have been used just as well as the blanket to keep the heat in.

Grigg

Denny, as a fellow IA and with all due respect its hydrogen embrittlement not embrutement which can happen in the plating process. Weeds

Now see here Weeds if that's the way Microsoft spell checker spells it, it must me right!
Ya got to admit it could be brutal if it fails cus O that, thar embrutlements!
All kiddin’ aside, Tks for catching that, tink ya know what I was aimin' for. After I got over the circle track stuff I got interested in aerobatics and scratch built a Pitts S1D and one of **** Wagner's Wagabond's, (a Vagabond clone). I plated all of the control linkage, sticks, torque tubes, all the small parts, i.e., aileron, rudder, elevator brackets, rudder peddles, levers, etc. As with the parts we made for the circle track cars, we treated them in accordance with ASTM B850-94 recommended by the plater and which I’m sure your familiar with since you’re an AI. We never had a failure due to cracking from “hydrogen embrittlement".

Anyway, I already lost this one to those durn HOT RODDERS! Just my hope no inexperienced youngster gets the wrong idea and goes and hurts him self or someone else with a botched suspension mod, that was my only intention.
Denny G

Denny, alls well that ends well and not to hijack the thread but what ever happened to the guy that used to do the Stagggerwings at Sandwich? Doc Yockey, Vern Yockey, something like that? Should we move to the Greasy Spoon? Weeds

Naw, I'm bout burned out on this one, I think 10micron has enough to make up his mine anyhow.
"Doc" Yockey’s, (not sure how he spelled it) hanger was right across the runway in my back yard. Probably shut it down for a couple of reasons, he wasn’t a kid you know and I think it just wasn’t profitable enough to keep the doors open. There are some shops that are operating on a much larger scale and can handle projects of that size more competitively. There’s a lot more to a Staggerwing than meets the eye. In fact I was just talking to a friend last month who lives at Poplar Grove Airport. He’s finished several large restorations, a Fairchild 24 was the last one, he just got rid of a Staggerwing because it was turning into more of a project than he thought could handle in a reasonable time and the cost to restore one is quite high.
Talk at ya later.
Denny Graham
Sandwich, IL

Denny - I don't think there was any loser there. We all should have gained something from that exchange of information. I certainly did, including a lot from you, sir.
Doug

Just a figure of speech Douglas, your correct on that account, I think we all pickup something for these discussions, heck, look at how Weeds taught me how to spell hydrogen embrutalment!
A thread caught my eye this morning about welding up split rims. I wanted to keep my yap shut but couldn’t help myself. Now there your really looking for some trouble! Although I’ll bet there are a few guys out there that have welded up rims for their stock cars and “never had a problem”.
Denny Graham
Sandwich, IL

Some things are better left to the pros who carry lots of liability insurance. That way if it all goes bad, your wife can afford a condo on the beach!

all the input is welcomed! the great thing is if i had any thoughts of the axle failing i would simply pull out my credit card and order one. and it sounds like asking all the questions was well worth it to me. now the question is: drop it or cut and weld one.