If you use the corn head grease it will not leak, but will liquefy when gears mesh. But if you ran it in 4x4 you would get some leakage, because of the crack, it's not a seal. But when the truck is sitting or gears not meshing, you won't have a class 3 or even class 1 leak, it will stay put! You see the blue from the silicon trick! What it looks like to me anyway.
Keep your ears open for new noises coming from the front end, and hands sensitive to new vibrations coming from the front end. You should be OK to get you by until you make a decision.
Good luck!
