How do I fix front leg wobble on G Plan dining chairs?

I have six (two with arms) teak G Plan dining chairs. They are in good condition except the front legs on some of them have loosened and started to move/wobble when the chair is moved forwards or backwards. I have had a look at the joints and whilst there are connecting wood braces, the actual join between the legs and the side pieces seems to have been made with a metal piece that has been forced into the wood. as opposed to a dowelled joint. The original glue has failed and the gap between the legs and the side pieces is only a millimeter which makes it impossible to re-glue them without dissassembling the whole front of the chair. I would appreciate any suggestion as to how to fix them as the chairs are very elegant compared to the heavy oak furniture in the shops to day.