Is it possible to MiG weld a cracked automotive transmission case?

After one of my kids ran over a curb there's a crack in the transmission case that allowed all the fluid to leak out over 4 hours. It's a old high mile SUV for my kid to drive and isn't worth 7K for a rebuilt transmission. I'm looking for a solution to buy us half a year to find something else.
Do you think a MiG weld on the crack is even possible without removing, draining, grinding clean etc.?