Advise on welding shafting

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I'm looking at a project that would involve making a shaft adapter by welding a cast steel piece onto a hardened steel shaft and am looking for advice on the best way of welding. The intent is to make a adapter that will connect a 29 spline male shaft to a 32 spline female for a truck transfer case. I'm planning to use the original output yoke (cast steel) machined suitably to mate with a short section of shafting cut from a transmission output shaft that fits into the 32 spline female section. I expect the shafting would be a high carbon mild steel, 1050 maybe? Is this consistent with your experiences? It's a stock Ford C6 output shaft so I doubt it's anything too fancy.I can do the machining to make the pieces fit and can get the alignment to work. (I hope) My question is how would you recommend welding? TIG? Stick? Anything fancy needed due to the cast steel and high carbon steel? I've got a Miller Big 40 and an HF-251 Tig box, so i can run stick or TIG up to about 300 amps. My skill at both is moderate.Thoughts?   Thanks,     ~John
Reply:Originally Posted by sdmulemanI'm looking at a project that would involve making a shaft adapter by welding a cast steel piece onto a hardened steel shaft and am looking for advice on the best way of welding. The intent is to make a adapter that will connect a 29 spline male shaft to a 32 spline female for a truck transfer case. I'm planning to use the original output yoke (cast steel) machined suitably to mate with a short section of shafting cut from a transmission output shaft that fits into the 32 spline female section. I expect the shafting would be a high carbon mild steel, 1050 maybe? Is this consistent with your experiences? It's a stock Ford C6 output shaft so I doubt it's anything too fancy.I can do the machining to make the pieces fit and can get the alignment to work. (I hope) My question is how would you recommend welding? TIG? Stick? Anything fancy needed due to the cast steel and high carbon steel? I've got a Miller Big 40 and an HF-251 Tig box, so i can run stick or TIG up to about 300 amps. My skill at both is moderate.Thoughts?   Thanks,     ~John
Reply:If it is all apart and I hope it is..The male shaft is hardened on the outside only..It's called "Case Hardening"..Goes about .020  .030 deep into the material..It's only for wear...You can just cut it off if you wish..Bore out the end..Heat shrink in the correct spline shaft in it's place..(Do the same thing with the bigger shaft but in reverse)...Weld and call it a day.If it was only that easy....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:Weld, rough machine, heat treat and final machine.  That assumes you know what metal you are working with in the first place."USMCPOP" First-born son: KIA  Iraq 1/26/05Syncrowave 250 w/ Coolmate 3Dialarc 250, Idealarc 250SP-175 +Firepower TIG 160S (gave the TA 161 STL to the son)Lincwelder AC180C (1952)Victor & Smith O/A torchesMiller spot welder
Reply:Wouldn't it be better to cut and weld for mock up, then take it to someone like Zap who could probably machine a new one out of better materials? I know it would probably be expensive, but it wouldn't snap in half under full power.kidtigger24  They think I’m crazy, but I know better. It is not I who am crazy. It is I who am MAD!
Reply:High carbon steel will crack before it even cools off without some specialized welding practices.  1050 would be considered very high carbon steel.  Typically most steel you weld is going to be 1010-1018 (that's 1-1.8% carbon by weight).  1020 is considered the upper limit of readily weldable steel.  Sure you can weld higher carbon content steels like 4130 but that's only very thin sections.  Once you add thickness like you would see on a shaft, you're asking for trouble.Last edited by 76GMC1500; 08-21-2012 at 10:55 PM.
Reply:Thanks all.My classes covered basic metallurgy but the curriculum focused more on the semiconductor industry and theory. Practical welding was never covered. I know enough to know that what i know is not nearly enough. Hence the reason I'm asking....I do not for sure know what material either part is. I know the yoke I'm using for the female splined section is cast.The right way to do this would be a solid machined section, but I'm guessing it would be very expensive. The hardest part would cutting blind internal splines, I'm not even sure how you would do that beyond maybe EDM. I don't have the budget for that. This part would be for personal use only, and worst case failure that I can think of would just immobilize the truck, possibly with further drivetrain damage.