Loose Steering wheel

I have a Ford E250 1998 w/ the Triton V 8, the van has a power steering leak that is currently being corrected but while dealing w, the problem of no pwr steering the steering wheel has become very loose to the point of seeming like it is going to fall off, and you have to have it positioned just right to be able to turn the key i have been told that i have to tighten a nuckle in the mechinism how do i do this ? please help.