Super M transmission crack

[Rock2001]

Wow, everything is falling apart now that I'm starting to put the tractor back together. The transmission input shaft isn't sliding into place very easily. As I was looking at why, I found a vertical crack in the transmission case between the countershaft and input shaft. How concerning should this be treated? I wouldn't have thought there would be that much stress there, but the fact that it is cracked would indicate maybe this is an issue. I can try to get the inside half welded, but I'm hesitant to mess with the gasket sealing surface or machined hole for the input shaft. It is barely visible, so I wouldn't THINK the trans oil would really leak here? But if there are forces trying to separate this at times, then I guess it would leak then. Any insight?

Thanks

 

[rustred]

Post ur crack. I don’t think welding it is a good idea due to shrinkage and the bore holes. Time to find ur best goo. V it out and fill it up. I would use Devcon. Or another case.

 

[used red MN]

I am not sure if that is rr’s attempt at humor, but I believe he is asking you to post a picture of it. No experience with running one with a crack there but my first impression would be that I doubt it would give any trouble if it was sealed up. There is a lot of meat there around the outside of those shaft bores that would seem to me that would hold it all together fairly reliably.
Do you know about the rubber band trick for installing the input shaft? Place a rubber band around the rollers of the bearing on the front of the top main transmission shaft. This will hold the ones on the bottom up so the input shaft can slide in. It will dissolve in the oil.

 

[BarnyardEngineering]

I would not doubt that it's been that way for a long long time. Possibly from water freezing in the case.

To weld it you'd have to completely disassemble the tractor and take it to a shop. If you're going to go that far I would seek out a replacement housing. A housing from any M or Super M is the same and will fit. Those housings are the last things to get sold off parts tractors so they should be pretty cheap. Super MTA would be different.

Otherwise I would leave it alone.

 

[caterpillar guy]

Is it really a crack or just a mold line ?

 

[rustred]

I am not sure if that is rr’s attempt at humor, but I believe he is asking you to post a picture of it. No experience with running one with a crack there but my first impression would be that I doubt it would give any trouble if it was sealed up. There is a lot of meat there around the outside of those shaft bores that would seem to me that would hold it all together fairly reliably.
Do you know about the rubber band trick for installing the input shaft? Place a rubber band around the rollers of the bearing on the front of the top main transmission shaft. This will hold the ones on the bottom up so the input shaft can slide in. It will dissolve in the oil.

well it could be humor also. if you have no experience with a crack, why would a person want oil dripping steady on the ground.? it is machine shop work as any welder would tell u also. that's why i wanted to see how bad the crack is. if its a big crack it would need attention, while a small crack might not leak. easier and cheaper to find another case.

 

[Rock2001]

Sorry I got distracted. It is very small. I only noticed it because I was trying to see if anything was holding up the input shaft from sliding in. I'm not even sure how well you can see it here. You can see something very noticeable in the unmachined portion inside, but I'm not sure if that section is a mold line maybe?

I would think as long as there are no forces expanding this area (I wouldn't think) then I should be able to use some sealant on the front face and gaskets and probably be fine?

 

[Janicholson]

I think it is a scratch that does not include a crack. Your call, but it does not appear to extent into the meat of the casting. Jim

 

[used red MN]

I think it is a scratch that does not include a crack. Your call, but it does not appear to extent into the meat of the casting. Jim

Jim, I am not sure of the wording of your first sentence?? But, I am trained in NDE (Nondestructive Evaluation) in the photo the blob right above the lower bearing snap ring is what would be referred to as “bleed out” it is oil weeping out of the crack. That is terminology used during a Dye Penetrant Test. Just like the diesel fuel leak trick with baby powder, if he puffed a little on there it would soak up the oil on the surface and indeed show you a crack.
In a real test you clean it with a special cleaner, then apply a red colored liquid dye. That would be left on it a prescribed time (dwell). After that the surface would be thoroughly wiped with a cloth damped with the cleaner. Then a white substance (developer) that interacts with the dye would be sprayed on much like a paint. Then where ever the dye “bleeds” out it tells us where a void is under the surface that is open to the surface, in this case a crack.
In actuality, a Magnetic Particle Test (Manaflux is a brand name) would be best to use on this because it is a ferrous metal (magnet will stick to it) In that case the area would be magnetized by a yoke and colored iron filings sprinkled on the area. Because the crack breaks the flow of magnetic flux in the metal, the filings draw to the edges of the crack. (You would only do this if it was disassembled you would not want the filings in your bearings)
Back to dye penetrant testing. The earliest form of that was used on railroad train wheels. The mechanic would apply fuel oil with a rag and then wipe it off with a cleaner that evaporated quickly acetone or gas. Then they applied powdered chalk, if the metal was cracking the fuel oil weeped out to the surface and the chalk would stick to those areas.
Sorry, but no awards will be given for the quality on his pictures.

 

[560Dennis]

look At the loc and stitch method for that

 

[caterpillar guy]

Sure looks like a crack to me. And will seep until it is replaced or fixed. I believe changing the case will be the cheapest and easiest option since there are dozens if not thousands of them around . Or find a cheap nonrunning tractor and swap halves would be the least work since it would be all assembled. And yes the picture with the weeping right above the bottom bearing and the mark in the picture just below that one says to me it is a crack. The Crack check with the dye would prove this out one way or the other without harm to the bearings installed in there and then your concern would be vindicated one way or the other.

 

[Janicholson]

Jim, I am not sure of the wording of your first sentence?? But, I am trained in NDE (Nondestructive Evaluation) in the photo the blob right above the lower bearing snap ring is what would be referred to as “bleed out” it is oil weeping out of the crack. That is terminology used during a Dye Penetrant Test. Just like the diesel fuel leak trick with baby powder, if he puffed a little on there it would soak up the oil on the surface and indeed show you a crack.
In a real test you clean it with a special cleaner, then apply a red colored liquid dye. That would be left on it a prescribed time (dwell). After that the surface would be thoroughly wiped with a cloth damped with the cleaner. Then a white substance (developer) that interacts with the dye would be sprayed on much like a paint. Then where ever the dye “bleeds” out it tells us where a void is under the surface that is open to the surface, in this case a crack.
In actuality, a Magnetic Particle Test (Manaflux is a brand name) would be best to use on this because it is a ferrous metal (magnet will stick to it) In that case the area would be magnetized by a yoke and colored iron filings sprinkled on the area. Because the crack breaks the flow of magnetic flux in the metal, the filings draw to the edges of the crack. (You would only do this if it was disassembled you would not want the filings in your bearings)
Back to dye penetrant testing. The earliest form of that was used on railroad train wheels. The mechanic would apply fuel oil with a rag and then wipe it off with a cleaner that evaporated quickly acetone or gas. Then they applied powdered chalk, if the metal was cracking the fuel oil weeped out to the surface and the chalk would stick to those areas.
Sorry, but no awards will be given for the quality on his pictures.

I believe in all the technical means as well. I magnified the image by clicking on it looking at the shiny bearing bore where there is a scratch very bottom) the material just below that scratch is (aparently) still solid. A good neodymium magnet on one side of the deformity, and some iron filings might be informative. all as good as can be. Jim

 

[Rock2001]

Here's the award winning pics. It is definitely a crack. But almost the entire front face is gasket-ed. If I put something like Indian Head shellac over the gaskets and the entire front crack, it wouldn't seal it well enough? The crack is above the oil level. I figured I could get away with it.

And looking up from the countershaft bore.

 

[Janicholson]

Here's the award winning pics. It is definitely a crack. But almost the entire front face is gasket-ed. If I put something like Indian Head shellac over the gaskets and the entire front crack, it wouldn't seal it well enough? The crack is above the oil level. I figured I could get away with it.

View attachment 69104

And looking up from the countershaft bore.
View attachment 69103

Bu Gum it is a full fledged crack. I would probably do as you are indicating. I would use #2 Permatex, it is tough and does not harden like shellac. On both sides! Jim

 

[used red MN]

Yep, I will give you the reward for pic …518! I would tape it all off and take an 1/8” Dremel bit and groove out crack about a 1/16” deep or a bit more right at the area between the two gaskets. I would mix up some JB weld. clean it with brake clean, and aplenty the JB. After it sets file it down flat. Done deal