Welding Heat Treated Cast Steel Gear

[thomastractorsvc]

Heat Treated Cast Steel Gear 1st/3d gear anyone ever try to weld one with success? Took to three machine shops no one want to give her ago, was told by one of them that for $800-$1000 they could make a new one. Should I keep looking or someone have a bright idea?

18 tooth gear, tooth is broken about 30% at corner and another is 5% chipped, not next to each other. I had an unrelated bearing issue that was making a noise. If I would never taken the transmission apart I wouldn't be worried about it, but if I don't try and fix the gear it will probably break.

 

[Transit]

Welding cast iron is very tricky, it can be done but how long it will last is a guess. Weigh that against the cost of a replacement.

 

[LD1]

What exactally is the gear for? Make/model?

There are places online where aftermarket and even used gears can be had for under $150 instead of the dealers ~$600 per gear:confused2:

 

[zzvyb6]

I broke a large gear (internal teeth) on my NH hay pickup wagon, Shear pin was too big. Broke the gear into about 5 pieces. Collected up as much as I could find, headed down to TSC for some nickle rod and used an old Sears AC buzzbox to put it back together. I bought the new gear anyways, but never put it in because the welded gear is just fine. Only words of caution are that you don't want to leave a lot of flash or excess metal on the piece because its so hard that a die grinder has trouble removing it. That cause some clearance/interference problems until I got it smoothed out.

Give it a try !

 

[Shield Arc]

I've had good luck welding cast steel with 312 stainless steel, and a rod called Super Missile Weld, also with just plain old 7018.

I saved this from another site, it might help you with at least heat treating.
Preclean to sound base metal making sure you remove all rust and scale, then I would preheat too 900º then let air cool until warm (removes stress), then reheat too 500º (reduces weld cracking), then I would use Lincolns Wearshield BU for pre build-up of the tooth, then ruff shape the teeth, then cap the last two passes with Lincoln ME hard surface rod using single stringerbeads then reheat too 500º and quench in oil.
Do not use more than 3 layers Lincoln ME, as it would be prone to cracking and fracture. The finished product will have about Rc59 hardness with 2 layers. You will want to use about 30-amps more than normal for a given electrode size. Do not use a weave bead as this is a fast freeze electrode and it will easy to in trap slag between passes.

 

[KWentling]

If you had brought that to the machine shop I work at we would have been the fourth not to want any part of it. Not saying it can't be repaired, but without knowing the metal composition and its weldability, heat treatment, etc. I think there would be too big of risk of causing a bigger problem. A repair like that would come with 30/30 guarantee. 30' or 30 seconds, which ever comes first.

Kim

 

[thomastractorsvc]

My thoughts were if you weld and machine for living you would know how to fix it ((20 years ago I could take this to any welder/ machine shop and never be turned away)). I know it would be a welded up gear with no guarantee but heck you think someone who does this all day would have a better shot at making it stick than a guy who does other things with his hands.

Seems now a days nobody wants to fix things, just replace components. When was the last time someone trouble shooted a repair before just replacing parts?

I guess I am old school , I try to fix it if I can and save people some money. The gear is obsolete and finding older internal uncommon tractor parts is getting hard. This part was in JD A,60,and 620/630 and most of the guys I deal with did not have it or it was damaged.

So what are the choices dont repair, weld it or charge more than the tractors worth?

 

[yomax4]

If it is really cast steel, (which I doubt ) You can easily Tig weld it with 312 Stainless. ( which is what Super Missile Weld is ) You can pre heat if you want to. Build up in stages . Weld a while, File a while..You can grind or file for a while until it work hardens and then that is what you will get. So. Be careful not to put on too much more than you need. Get it close and file it down. Put on more etc. I do this all the time with Ring Gears, Pinions and Sprockets. Same applies if it is Cast Iron. I am presuming this is a fairly small gear say less that 12" ? If you can't fix it or find anyone to fix it. Shoot me a note. Maybe we can work something out.

 

[Wayne_H]

My thoughts were if you weld and machine for living you would know how to fix it ((20 years ago I could take this to any welder/ machine shop and never be turned away)). I know it would be a welded up gear with no guarantee but heck you think someone who does this all day would have a better shot at making it stick than a guy who does other things with his hands.

Seems now a days nobody wants to fix things, just replace components. When was the last time someone trouble shooted a repair before just replacing parts?

I guess I am old school , I try to fix it if I can and save people some money. The gear is obsolete and finding older internal uncommon tractor parts is getting hard. This part was in JD A,60,and 620/630 and most of the guys I deal with did not have it or it was damaged.

So what are the choices dont repair, weld it or charge more than the tractors worth?

Well, there is a lot of scrapped A's and 60's around. I am certain I can find the gear you want, what is the JD part # please? Parts like the internal gears that often do not fail are easy to find for these machines. Now if you are looking for OEM pistons for a pony motor for a diesel 2 Cylinder, that is a different story...

Wayne

Wayne

 

[AlanB]

My thoughts were if you weld and machine for living you would know how to fix it ((20 years ago I could take this to any welder/ machine shop and never be turned away)). I know it would be a welded up gear with no guarantee but heck you think someone who does this all day would have a better shot at making it stick than a guy who does other things with his hands.

Seems now a days nobody wants to fix things, just replace components. When was the last time someone trouble shooted a repair before just replacing parts?

I guess I am old school , I try to fix it if I can and save people some money. The gear is obsolete and finding older internal uncommon tractor parts is getting hard. This part was in JD A,60,and 620/630 and most of the guys I deal with did not have it or it was damaged.

So what are the choices dont repair, weld it or charge more than the tractors worth?

The problem is, that folks are a bit too happy to sue now days. Of course it is not you, but how does the machine shop know that?
You are walking in thinking you will pay your money and take your chances. You understand that there are risks involved in trying to repair this way, but are willing to assume that risk. While at the same time seeking to minimize that risk by having someone that welds more than you do the work. (if you don't think welding a cast gear is risky, just disregard and do it yourself)

The machine shop sees someone he does not know, walking in and asking to do a flaky repair, for very little money, and then install it in an expensive piece where if it breaks, and the chunks get floating around it has the potential to cause a lot of damage. Then that person coming back and causing them grief over a $50 to $100 job, threatening to sue, take them to small claims court, badmouthing them etc. The potential problems, far outweigh the small amount of cash they stand to make if it all goes well.

What you need is someone you know, that knows that you won't sue them if it all goes to poo and munches the other pieces. Hang out, buy him a 6 pack while he welds that thing up, and then put it back together.

Or as someone else said, if there are used ones out there, if you can find one where you can get individual pieces, your in money.

Good luck, hope you get it sorted around.