Unfortunately, if that is the case, the engine and trans would have to be pulled forward, or I believe, someone may have moved the rear axle enough to separate the drive shaft from the yoke.
Hold your horses! If the source of the leak is from the gaskets in the universal joint ball collar, the gaskets can be replaced by lowering the torque tube. Unfortunately it’s not as easy as it sounds, but is doable. Let the OP respond as to the source of the leak first before we get into that procedure.