A B737-300 ON INITIAL CLB AT 500 FT DECLARED AN EMER AND DIVERTED BECAUSE THEY WERE UNABLE TO RETRACT THE LNDG GEAR CAUSED BY THE GEAR GND SHIFT TELEFLEX PINNED.

Narrative

ACFT JUST COMPLETED A 'C' CHK AND WAS BROUGHT TO GATE BY MAINT. WHILE WE WERE WAITING FOR THE FINAL SIGN-OFF FROM MAINT FOR THE CHK; I ADVISED GATE MECH THAT THERE WERE NO BRIEFING CARDS IN THE PAX SEAT BACKS; WET PAINT SIGNS WERE IN THE BLUE ROOM AND THE CARPET WAS COVERED WITH PLASTIC. THESE ISSUES WERE TAKEN CARE OF AT THE GATE. WE WERE CLRED ON THE PORTE 3 DEP. ON INITIAL CLB THE LNDG GEAR WOULD NOT RETRACT. ADVISED ATC OF PROB AND ASKED FOR VECTORS IN THE LCL AREA WHILE WE RESOLVED PROB. WE WERE LEVEL AT 4000 FT; 210 KTS; GEAR DOWN; FLAPS 1 DEG; COPLT WAS PF AND HANDLING ATC. I CONSULTED THE 'LNDG GEAR LEVER WILL NOT MOVE UP' IRREGULAR CHKLIST. THE FIRST 4 STEPS WERE SUCCESSFULLY COMPLETED (DOWN TO THE LNDG GEAR LEVER -- OFF; LNDG GEAR LEVER SOLENOID HAS FAILED -- CHKLIST IS COMPLETE). PER THE CHKLIST; THE ACFT WAS IN THE FLT MODE AND THE LNDG GEAR LEVER SOLENOID HAD FAILED. WE THEN ATTEMPTED TO CONTINUE OUR CLB; BUT RECEIVED A TKOF WARNING HORN. I WENT BACK TO THE CHKLIST AND FOUND IT PERPLEXING BECAUSE WE HAD COMPLIED WITH THE REQUIREMENTS OF THE INITIAL 4 STEPS. I RECHKED ALL CIRCUIT BREAKERS AND INITIATED A CALL TO MAINT CTL. (COMMERCIAL RADIO HAD DIFFICULTY PATCHING US THROUGH TO A MAINT CTLR. I RECEIVED AN ACARS MESSAGE FROM MAINT CTL ADVISING ME THAT COMMERCIAL RADIO WAS HAVING PROBS AND SUGGESTING I TRY TO GO THROUGH LINE MAINT. I ALSO RECEIVED A MESSAGE FROM LINE MAINT ADVISING ME TO GO TO COMMERCIAL RADIO. I SENT A MESSAGE TO DISPATCH ADVISING I WOULD BE RETURNING TO SFO. AFTER TALKING WITH THE MAINT CTLR; DISPATCH DECLARED AN AMBER ALERT. DIFFICULTY IN ESTABLISHING COMS PLAGUED ME THROUGHOUT THIS EVENT.) I TALKED WITH LINE MAINT AND MAINT CTLR AND I CAME TO THE CONCLUSION THAT THE AIR-TO- GND RELAY SWITCH WAS IN THE GND MODE AND I WAS TO FOLLOW THE NEXT PART OF THE CHKLIST. THE REMAINDER OF THE CHKLIST PROVIDED ME WITH MORE PROBS THAN ANSWERS -- LIGHTS/NO LIGHTS; WARNING HORNS; STICK SHAKERS; PACK TRIPS -- AND NONE OF THESE WERE ADDRESSED ON THE CHKLIST. LATER REVIEW OF MAINT RECORDS SHOWED CAUSE OF MALFUNCTION TO BE 'RIG PIN TELEFLEXSW PACK ON R-HAND MAIN GEAR.' THIS PIN IS LOCATED IN THE FORWARD; FAR UPPER R-HAND CORNER OF THE WHEEL WELL. VIEWING OF THIS AREA CAN BE OBSCURED BY THE HYD RESERVOIR. I DON'T KNOW WHETHER OR NOT THIS PIN HAD A FLAG ON IT; BUT DUE TO ITS LOCATION IT COULD BE MISSED (I DIDN'T NOTICE ANYTHING ON THE WALK-AROUND AND MAINT HAD JUST RELEASED THE PLANE FROM A 'C' CHK -- APPARENTLY THEY MISSED IT TOO).