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Thread: Axle Shaft Steel
04-06-2005, 11:50 PM #1
What kind of steel are axle shafts made of and what welding rod,method would you use to weld one back together? Have stick and tig.
04-06-2005, 11:57 PM #2
Quite often, heat treated C4140 would be used on an automotive drive axle. It is difficult to weld 4140 without getting a hard zone on each side of the weld, where the puddle picks up some alloys. A high preheat temp might help lessen this tendency. A low alloy rod like a 11018 might make a decent match.
I would not advise welding any axle which will be put into service at high speeds on a public highway.
04-07-2005, 12:17 AM #3
When we made rear ends at work the axles where forged 4140 that was induction heat treated on the splines and bearing diameters. In no terms would I recomend welding an axle that is going in a vehicle. The same goes for front spindles IMO
04-07-2005, 12:54 AM #4
I do not suggest welding them, but you can do it.
They are 4140.
You will need to sleeve the axle and weld the sleeve. The sleeve needs to be cut at an angle on either side to maximize the amount of surface area of the weld.
Axle..../.... Sleeve .... / Axle
Ignore the periods. Ascii art doesn't seem to work well here [img]smile.gif[/img]
04-07-2005, 01:02 AM #5
All that said is good, but amazingly good welds are made on a regular basis in such items as oil well downhole drilling tools. Some of these "tool joints" are holding up many tons of drill string while also delivering huge amounts of torque during drilling.
All has to do with knowing exactly what 4140/4142 needs to be perfectly welded.
That is why the outfits involved in this work regularly employ welding engineers.
04-07-2005, 01:06 AM #6
the redneck way of doing it.
line your shafts up in a piece of angle iron. tack all the way around. After tacking, find yourself a nice flat table. Roll the axle and look to make sure it's not wobbling...if it is, grind welds away and try again [img]smile.gif[/img] If it isn't, grind welds down so you can slip the sleve on.
I imagine that after welding, you should probably use a torch and try to normalize the HAZ.
04-07-2005, 01:35 AM #7
The machining and fitting the pieces together is no problem.
Just wondering how to glue them back together :
filler rod ,preheat?,heat treat ect. suggestions.
The axels are for a full floater setup so breakage would not effect losing a wheel and mostly off road application.
04-07-2005, 01:55 AM #8
I've welded a number of GM and Ford axles back when I had free access to the best metallurgical lab the Government could provide. The early and mid '60's GM axles I welded were determined to be equivalent to 1130 and 11018 D-2 as the most suitable rod. I forget what the Ford axles corresponded to but I do remember that 11018 D-2 was the reccommended stuff.
41xx is not a given for all high strength automotive applications as it's relatively expensive for general automotive use if something lower in cost is available. 1130 is a manganese steel not unlike that used in switch components for heavy rail traffic. It has good as forged strength, heat treats well to lower hardness like about Rc 35, and it's very tough and fatigue resistant. Metallurgically its more forgiving.
The weld prep prescibed for my axle welding adventures (I shortened maybe 50 sets) was a simple jig for alignment, J weld with runput tabs, upsetting the edge of the base metal to raise it above the as forged surface, root pass and grind back to sound metal, then alternate passes on each side to control distortion and to hold the axles straight and in alignment. Pre-heat to 450, interpass at 600 or less. Post-heat to 900 for 10 minutes and air cool. Grind off the run-out tabs and fair the weld into the base metal leaving a slight swelling. Hot forging was permitting to adjust length and correct offset and final straightness.
The point is if you don't know from actual tests what your welding when it comes to high strenght high confidence parts then you don't know what you're doing; you're gambling with the safety of the customer and anyone in the failure path should you be wrong.
My advice to anyone contemplating welding axles, front wheel spindles, and other high confidence parts is to pay the money and get the metal tested before you weld. Blithe assurances from ignorant but well meaning buddies (hey-ull I've welded a million of 'em and never had a problem) do you no good. Slick magazine articles written on bum research is worthless in the face of the need to have all the variables (material, process, filler metal, heat threatment, post welt testing, etc) nailed down in terms of numbers and hard knowledge.
Do it right the first time and you won't have to bury any mistakes or explain to the widow or the jury how Bubba said it was OK.
04-07-2005, 02:08 AM #9
The shafts I want to fab. are for low speed off road use and are full floating.
04-07-2005, 02:24 AM #10
I double check an axle for straightness in a lathe. Chuck up the axle and run it in the slow side. When you find a high side tap down at the end of the axle. If it needs encouraging warm it up with a torch. Work slowly then indicate the axle. Should be almost dead on with some work. Dont know if this helps anyone but I tried.
04-07-2005, 02:35 AM #11
OOOOPS, forgot to add this. I have seen an old lathe run at slow speed to weld a drive shaft in. The the lathe is rotated and the shaft is welded as it spins. This makes a nice strong, penetrating weld. Then its indicated and high spots are heat shrunk with a torch. Then the u-joints are connected and its checked for vibration.
04-07-2005, 03:12 AM #12
So what do you "tap" the high side with to make it move, and "stay moved"? A 30 lb sledge? That's a little tough on the tailcenter, isn't it?
04-07-2005, 03:25 AM #13
Most factory axles are 1037 and then induction hardened. The factorys are not not going to spend the money for 4140 for your everyday non high performance cars. I too would never weld on one. BIG LAWSUIT. Cut, respline and induction harden works great.
04-07-2005, 04:37 AM #14
Just because the application is "low speed, off road" and full floating to boot, does not mean you won't be in big trouble if you break and axle under load. I have seen cars spin 180* when axles break even at <50 mph. The spin was instantaneous and the car was being driven by and experienced licensed race car driver. It happened right in front of me. The car spun around and went on an OCE so fast I almost missed it. Anyone who would take a chance on welding an axle on anything bigger than a Radio Flyer, when custom axles can be had for as little as $250 a set is up for a Darwin Award.
04-07-2005, 10:41 AM #15
Thanks for the replies?
The 18hp 4x4 garden tractor type vehicle I plan on fabing shouldn't attract any law suits and breakage shouldn't be a big concern just want to make the axles as strong as possible the first time. As for buying axles I don't expect to have $250 in the whole project.
04-07-2005, 11:16 AM #16
I quoted a job a while back for axle blanks that were to be roll splined on both ends. I assume they were going into some sort of floater rear end that had an outboard spline at the hub. The material on these was 1330, which I think is also a manganese steel. Forrest's statement about axles from the 60's also being manganese steel shows just how much some things really don't change that much over time so long as they work.
04-07-2005, 11:38 AM #17
That's pretty much what I want to do,using locking hubs on the outer end so I can disconnect the axles?
04-07-2005, 01:18 PM #18
Ok...I have to change my above post [img]smile.gif[/img]
4140 is what differential pins are made of. Ya know, the pin in the differential that your gears float on.
Most of the steel's that I worked with were manganese steel, 1050 rings a bell [img]smile.gif[/img]
That was a dang long time ago!
04-07-2005, 06:42 PM #19
We recently made some modified axles. We used the CV joints from a geo metro and a smaller u joint weld-on type for shaft. We use 4130 tube for the center section to save on weight. To get more surface area of weld, we used a "fish mouth" on the tube. The shafts we made are designed to withstand about 700 ft lbs of torque and used on an off road vehicle.
04-07-2005, 06:58 PM #20
I have done the same thing as GisMo a dozen or so times. The first set of half shafts failed after ~60 hours of use. After changing our method slightly we haven't had another failure. Here is the method we now use to lengthen ATV shafts.
1. Remove CV joints
2. Cut shaft in half
3. Turn down cut sections to fit ID of 4130 tube
4. Fishmouth tube at each end
5. Drill small vent hole in middle of tube
8. Cool very slowly
9. Reaheat to dull orange in an attempt to remove any stress in the HAZ
None of our steps are based on any hard data, just tidbits gleaned from various sources. If I had the instrumentation I would enjoy running some experiments though.