AN MD80 ON CLB AT 15000 FT DECLARED AN EMER DUE TO YOKE BINDING WHEN PASSING CENTER POSITION. INCREASED SPD INCREASED YOKE BINDING. CREW RETURNED TO DEP ARPT.

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ON CLB OUT; I NOTICED THE YOKE WOULD BIND UP WHEN TURNING PAST THE CENTER POSITION AS I WAS SPDING UP (FASTER THAN 250 KTS). I TALKED WITH MAINT CTL AND DISPATCH AND RETURNED TO LAND. I DECLARED AN EMER AND MADE A SLOW TURN FOR ZZZ. I WAS ABLE TO FOLLOW A 3 TO 1 PROFILE INTO ZZZ WITH ONLY 2 180 DEG TURNS FOR RWY 16L. (WE USED RWY 16L FOR THE LENGTH.) WE WERE 9500 LBS OVERWT WHEN WE LANDED. TOUCHDOWN WAS AT 100 FT PER MIN. WE HAD NO FURTHER PROBLEMS WITH THE YOKE BINDING WHEN WE SLOWED BELOW 250 KTS. I DON'T UNDERSTAND WHY THE INCREASE IN SPD MADE THE YOKE BIND.CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR SAID THE BINDING WAS FELT ON THE CAPT'S YOKE AND THE FO'S WHEN PASSING THROUGH THE CENTER POSITION. THE RPTR STILL CAN'T EXPLAIN WHY THE BINDING INCREASED AS THE SPD INCREASED. THE RPTR FOLLOWED UP TO OBTAIN THE MAINT ACTION TAKEN AND DISCOVERED THE PROBLEM WAS ON THE AILERONS AND AILERON TAB HINGES; ADDING; LUBRICATION OF THE AILERONS AND AILERON TAB HINGES PLUS RETORQING OF THE AILERON TAB HINGES CORRECTED THE PROBLEM.