1998 dse....

Hi landy lovers.... can any one tell me about the front diff..the garage told me that the rumble from the front when i turn left is me diff on its way out.. is a diy rebuld a possable.. if so what do i replace??... if not are the 4.6,4.0 the same as the 2.5?? and whats all this 2 pin or 4 pin malarkey all about?? any help would be great... many thanks stuart..