96 Z71, 350, 4L60E.
Tranny was just fully built so please no (now is a good time to build it up comments). You can imagine my excitement to find I still have this leak after getting it rebuilt. I didn't know it was cracked when I first pulled it out and decided to build it up, I thought it was blowing the fluid out of the vent. The vent tube was wet and I thought it was coming from the tube and then getting flung everywhere from the front drive shaft.
When I put it on jack stands and let it idle in reverse nothing comes out. Put it in drive and immediately it starts leaking and will be dripping from the pan within a minute or 2. After I had driven it it looks as though it will actually spray out of the crack as there is fluid on the bottom of the floor and on the wiring harness above the crack.
I'm pretty sure it was caused by a bent drive shaft, which has since been replaced. Could this be fixed by welding it without removing the tranny or even with JB Weld or does the case have to be replaced?