[chidog]

There is no way to weld that in car, since there is no way to clean it in car. To replace that case is almost a transmission rebuild, the case can not be replaced with the transmission in the car or on the engine. You don't just go buy a salvage transmission case part, you will be buying a salvage transmission to take the part off of, unless maybe at a pick n pull. Disassembly required. It took a huge amount of torque to do that crack, did he use an impact wrench?
In support of the mechanic, how come all that oily mess on that cross member? Maybe someone else cracked it before maybe a smaller crack, and is why the car was sold?
To me it looks like its been leaking for awhile.

 

[chidog]

There is no way in the world that epoxy will hold. Like I said before there is no way to clean it in car, yeah you may think you clean it good enough but remember unless he flipped the car upside down, that fluid will continue to drain. Maybe in 2 years it may all drain out good enough I don't know. But there is no way the crack was cleaned out and no way to stop the constant draining of oil. The fluid prevents any in car and assembled transmission welding or epoxy ing, type fix. Just like you can not paint over an oil covered part you can not epoxy it either. Welding with oil will just pollute the weld, tig welding won't work, nor the soldering type welding either, can have no oil.
He may have sprayed brake clean on that case but still he sure didn't clean it well on the outside at all. It should have be aggressively wire brushed or sanded rough, to help the epoxy stick. But then its the oil in the cracks that will sooner or later cause it to leak again. I would not accept that fix at all.

 

[chidog]

With the huge costs of everything nowadays, this is why anyone that is charging to do mechanic work needs insurance. I know of an auto repair place that the mechanic had a small dowel pin drop in an intake port and ruined an engine, the insurance paid for it. And this is also likely why it costs so much to have your car worked on.

 

[chidog]

Most all repair out fits Dealer and independent are going to say take it to a transmission shop. One other thing, I am not real sure but there could be a possibility that the case halves are a matched set and need to be replaced as a unit. Maybe someone can look it up online and check availability and prices.