Chevrolet Repair: 87 chevy speedometer, speedo needle, tail shaft

Question
I have a 1987 Chevy truck and the speedometer does not work, I am wondering how much would it cost to replace it? and can I replace it myself or should I go to the shop?

Answer
IS THE SPPED ITSELF BAD OR THE SENSOR OR CABLE..SENSOR OR CABLE IS NOT HARD TO CHANGE. THE SPEEDO IN THE DASH THE DASH FACE NEEDS TO BE REMOVED,NOT THAT HARD. A USE SPEEDO MAYBE $40.00
THE TAIL SHAF GEAR MAYBE THE PROBLEM AS WELL..GET BACK TO ME WITH WHAT ENG YOU HAVE AND TRANS AND I WILL GIVE YOU MORE INFO,,, THANK YOU TOM.

PS///PS.. HI SARAH AGAIN,I WAS IN A RUSH WHEN I FIRST ANSWERED THIS QUESTION,I WILL DO BATTER NOW..SORRY ABOUT THAT... YOUR TRUCK HAS A CABLE TO THE SPEED ITSELF..SO THIS WILL BE EASIER TO DIAGNOSE. BY CHANCE DID THE SPEEDO NEEDLE ITSELF START TO JUMP UP AND DOWN FOR AWHILE AND THEN STOP ??IF IT DID MORE THEN LIKELY IT IS THE CABLE ITSELF...THIS CABLE RUNS FROM THE DRIVERS SIDE OF TRANSMISSION UP INTO BEHIND THE DASH WHICH IS HELD IN WITH A CLIP BEHIND THE SPEEDO ITSELF, PUSH THE CLIP IN AND PULL THE CABLE STRAIGHT OUT. HOWEVER BEFORE YOU DO THIS REMOVE THE TRANSMISSION SIDE OF CABLE AND SPIN THE CABLE AS FAST AS YOU CAN ONE WAY AND THEN THE OTHER,HAVE SOMEONE IN THE TRUCK AND SEE IF THE SPEEDO NEEDLE JUMPS UP AND DOWN,, IF SO THE CABLE AND SPEEDO ARE MORE THEN LIKELY OK..THE PROBLEM IS EITHER THE PLASTIC GEAR THAT IS BOLTED TO THE SIDE OF THE TRANS OR THE DRIVIN GEAR ON THE TAIL SHAFT OF TRANS..REMOVE THE GEAR FROM THE TRANS THAT THE CABLE WENT INTO,MAKE SURE THIS GEAR IS FLAT AND NOT WORN CONCAVE,IF SO REPLACE THIS GEAR..IF THIS GEAR LOOKS GOOD CK THE GEAR ON THE TAIL SHAFT,WHEN YOU REMOVE THE GEAR FROM THE SIDE OF TRANS YOU WILL BE ABLE TO LOOK INTO THE TAIL SHAFT AND CK THIS GEAR,SOME GEARS ARE METAL AND SOME ARE PLASTIC. THIS GEAR SHOULD ALSO BE FLAT NOT CONCAVE..SOMETIMES THE GEAR ON THE TAIL SHAFT WILL MOVE DOWN FROM THE SHAFT,BECAUSE THE CLIP THAT HOLDS THE GEAR TO THE SHAFT BREAKS..ALL OF THE PARTS ABOVE ARE VERY INEXPENSIVE..HOWEVER THE SPEEDO ITSELF WILL BE A LITTLE EXPENSIVE. WOULD CK AT THE JUNK YARD FOR THIS..I GAVE YOU SOME HOME WROK. WHEN YOU FIND THE PROBLEM GET BACK TO ME IF YOU NEED MORE INFO.THIS SHOULD BE A EASY FIX. I HOPE THIS HELPS YOU..PLEASE WHEN YOU LEAVE THIS SITE WOULD YOU PLEASE RATE MY ANSWER. THANK YOU TOM..