Questions about axle repair

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I have a front axle from my F250 that has been damaged by a dry bearing.  A new axle half will cost about $160 at the Ford dealer.  I'd like to try to repair the old one.  In the picture, the shiny spot with the gap under the ruler is worn about .035".  I'd like to build up by welding, then turn it down on a lathe.  I've got  MIG and stick welders and an old Atlas lathe.  Welding skills are OK, lathe skills are beginner.  I've got ideas about how to go about it, but I'm sure some of you guys could whip this out before the morning coffee break.Give me some guidance here.  And Thanks!Gary Attached Images
Reply:send zap a PM to check out this thread....he will have a wealth of information for you.-Graham-Mechanical EngineerAutosport Mechanic/Fabricator
Reply:If the bearing in the picture runs directly on the shaft you don't have anywhere near the tools you'd need to make a lasting repair.  You would have to anneal the shaft, weld it, turn it down to slightly oversize, heat treat it to a pretty high hardness, then finish by toolpost grinding and polishing it to the final size.  If it had an inner race it would be an entirely different story, but from the pics it's using the shaft as the inner race.
Reply:Don't bother..Look in junkyards and save yourself the hassle of trying to do the near impossible..Even I would not try that.....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:$160 sounds cheap compared the labor you will put into it. I am fairly new welder, but I use to purchase parts for underground construction equipment. welding, annealing, machining, and heatreating sounds dead on the head. I would think one part annealing and HT could cost near that for one part run. Plus the HTer is going to have to know what material it is exactly.How about finding a desent one at a junkyard???Just my .02,DanMy instructor said someone will catch on fire during class...He wasn't joking!!
Reply:Agreed, I wouldn't do build that up and turn it down myself.  As stated check the junk yards.I'm a Lover, Fighter, Wild horse Rider, and a pretty good welding man......
Reply:I say buy the new axle. But try welding and turning it down anyway just for the practice if you have some free time.Lincoln AC/DC 225/125 Stick Linde HDA-300 MillerMatic DVI MIG Miller Dynasty 200DX Hypertherm Powermax 1000
Reply:Originally Posted by zapsterDon't bother..Look in junkyards and save yourself the hassle of trying to do the near impossible..Even I would not try that.....zap!
Reply:Because you'll never be able to restore the fatigue resistance necessary for that application after welding.
Reply:You have what, a Dana 60? There is no way I'd weld that thing. The local Pull-a-Part here sells axles for $75. You can find complete used axles anywhere for under what the stealership wants for a shaft.
Reply:Originally Posted by BikespotQuote:Originally Posted by zapster  Don't bother..Look in junkyards and save yourself the hassle of trying to do the near impossible..Even I would not try that.....zap! Why not?Because its harden steel?
Reply:Originally Posted by TubularFabI had to laugh at this one!  I guess unless you're Zap some on here don't listen to a word you say.  The reason you would not want to do this is clearly spelled out in the post directly above Zap's!So Zap - would you please cut and paste some of the following statement into a post following mine so more people can have the benefit of believing it?The fact that it's a hardened part does play into it, but the biggest obstacle to overcome to repair that part is the fact that the surface of the repair has to form the inner race for that needle bearing.  In other words, after you anneal the part, carefully weld it up (with a proper heat treatable alloy!), machine it a couple of thousands oversize, and heat treat it back to the correct hardness to be compatible with the needles in the bearing you still aren't done.  The final step is to toolpost grind it to the exact size and perfect finish for the bearing.  If you have anything the slightest bit off the extremely hard rollers of that bearing will chew it up within a matter of miles.So, based on what it would take to repair it a used axle or even a new one would be a much cheaper, much more reliable repair.
Reply:Is the diameter of the spline larger or smaller than the worst part of the damaged area?Joewww.CummingsHauling.com
Reply:Like TubularFab told you (and others as well), get a new/used axle.  There is no real practical way to repair it.Joe, the spline OD -has- to be the same or slightly smaller than the shaft diameter in this case.  Otherwire the bearing can't get past the spline and onto the shaft.  Other spline shafts may have the spline OD slightly greater that the shaft diameter if a bearing/seal/shatever doesn't have to get over the spline and onto the shaft from that end.  The spline OD may be made slightly larger than the shaft to get a better match in the strength of the spline compared to the shaft (the spline is weaker than the plain shaft of the same diameter).
Reply:OK you guys, laugh away.  My dad did it 3X on a 64 cheby van.  I saw him.  He built up the shaft with 680 and machined it down to size then heated and quenched it then polished it.  He did one side twice and the other side once.  It worked.  Would I do it?  Nope.I agree, go find a used axle, put it in the truck and be on your merry way.Zap, the wheel won't wobble, it only drives the front axle.DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:Originally Posted by TubularFabI had to laugh at this one!  I guess unless you're Zap some on here don't listen to a word you say.  The reason you would not want to do this is clearly spelled out in the post directly above Zap's!So Zap - would you please cut and paste some of the following statement into a post following mine so more people can have the benefit of believing it?The fact that it's a hardened part does play into it, but the biggest obstacle to overcome to repair that part is the fact that the surface of the repair has to form the inner race for that needle bearing.  In other words, after you anneal the part, carefully weld it up (with a proper heat treatable alloy!), machine it a couple of thousands oversize, and heat treat it back to the correct hardness to be compatible with the needles in the bearing you still aren't done.  The final step is to toolpost grind it to the exact size and perfect finish for the bearing.  If you have anything the slightest bit off the extremely hard rollers of that bearing will chew it up within a matter of miles.So, based on what it would take to repair it a used axle or even a new one would be a much cheaper, much more reliable repair.
Reply:OK guys, thanks for the insight.  I guess I'm slinking off to the junkyards and the internet.  Heck, it seemed like a good idea...  Gary
Reply:Originally Posted by MoonRiseLike TubularFab told you (and others as well), get a new/used axle.  There is no real practical way to repair it.Joe, the spline OD -has- to be the same or slightly smaller than the shaft diameter in this case.  Otherwire the bearing can't get past the spline and onto the shaft.  Other spline shafts may have the spline OD slightly greater that the shaft diameter if a bearing/seal/shatever doesn't have to get over the spline and onto the shaft from that end.  The spline OD may be made slightly larger than the shaft to get a better match in the strength of the spline compared to the shaft (the spline is weaker than the plain shaft of the same diameter).
Reply:Originally Posted by David RZap, the wheel won't wobble, it only drives the front axle.David
Reply:Just another question about this. Some time 25 years ago at work we had a demo of a torch that you would spray a weld to build up a shaft on a lathe. Then you could turn it down to size .  Does anybody use that process anymore ?
Reply:Thermal spraying is still used, I've seen it done to repair worn out crankshafts. its either O/A or plasma. I've never seen one used but they also have small torches (like a brazing torch) with a hopper of powdered metal... you can use to build up and hardface things. A smaller hand operated version of the kind ive seen that runs in conjunction with a lathe.Last edited by CaptainWilly; 03-15-2008 at 10:38 AM.I like to party!
Reply:Thanks , you know after the demo the newboss asked if we thought we could use it and old millwright said there is one of those things on the wall over there. That ended that. Only time I ever saw one. I wonder if it still there? Bet nobody knows what it is ?