1939 Transmission case crack

D

Duke

Senior Member
I was just about to start reassembling my transmission when I noticed this crack or casting flaw. Should I use it or move on to another case? I have another one I can clean up.
Thanks
 

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mildly heat the case at the crack it should highlight the extent of it . Find the end and stop drill 1/8 is normally enough that will stop it travelling, a little filler sand smooth and paint no problem
 
DavidG said:
Alan and Mike,


Your responses strike me as out of character.:)
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I was wondering how long it would be until someone would note that.
David, my car? And if I had another case? I'd use the other case.
You got me :)
 
Kube said:
I was wondering how long it would be until someone would note that.
David, my car? And if I had another case? I'd use the other case.
You got me :)
Click to expand...

Whew! Sleep will come easier tonight. The earth is still spinning on it's axis!
 
I find it odd that a crack would be in such a place. Are we sure its not just a casting mark?
 
Kube said:
I was wondering how long it would be until someone would note that.
David, my car? And if I had another case? I'd use the other case.
You got me :)
Click to expand...

Nope, I don't buy that. Mike would V it out, weld it, grind it, sand it, fill it, prime it, wet sand it, prime it again, ad infinitum.
 
It wouldn't be that hard to braze the inside if it bothered you that much. I'm with the crowd that says use the case and be particularly "gentle" when you torque that last bolt!!
 
I always stop drill a crack and repair it by brazing if I plan on using it. Replace it if you have the where with all. Cast iron is best repaired by fusion welding but that is an expensive process. It's cheaper to find another unless it's a rare part or a person wants to keep the serial number stamped on if applicable.

Die penetrant will confirm a crack. Manaflux can also confirm a crack but is not as easy to perform on large parts. There are other ways but a person would have to take it to an NDT shop to get most things done. Die penetrant and developer can be done by just about anybody but if it looks like a crack it probably is. They usually crack between the countershaft bore and the input shaft bearing bore. Outer flange cracks are not very common. When properly bolted up, it's pretty well supported in that area.
 
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It looks like it is a casing flaw that doesn’t go through on the inner area, but is a crack on the flange. The thrust surfaces on this case are the best of the cases I have. I think I will use it and carefully tighten the bolt with a good flat washer to help spread the pressure.
Thank you for all the help!
 
ford38v8 said:
Nope, I don't buy that. Mike would V it out, weld it, grind it, sand it, fill it, prime it, wet sand it, prime it again, ad infinitum.
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If I didn't have another case perhaps. Okay, YES, I would do just as you figured.
Man, I can't get away with anything around here.
I will keep tryin' though...
 
Kube said:
If I didn't have another case perhaps. Okay, YES, I would do just as you figured.
Man, I can't get away with anything around here.
I will keep tryin' though...
Click to expand...

When you get old and bald like me, I’m quite sure you’ll then wet sand your noggin and use carnuba on it.
 
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