Quoting deez:
Damn, that thing does not want to come out! Any tricks, or should it just lift out?
Did you unscrew the cable from the gear unit first? you wnat to atleast make sure that you can unscrew the cable first because they can become corroded on to the unit. if it is, it will be a little more difficult to pull it out because the gear unit needs to spin to come "straight up" if you can get the cable off, then great. Now you need to just tap on it lightly with something to get it to twist back and forth. A little WD40 would help out or what ever lube you have. After it wants to move around, twist it back and forth while pulling up on it. It should pop up after a few twist.
If this isn't the cause of the speedo failure, then you need to check the cable. First see if it spins freely by hand. If so, spin the cable slowly with a drill. I say slowly, but it has to be faster then by hand. While doing that, have some one watch the speedo to see if it moves. "YOU NEED TO MAKE SURE IT IS SPINING THE CORRECT WAY!" I don't remeber if it goes clockwise or counter clockwise right off hand, but someone might know. What will happen if you spin it back wards with a drill is it will become un-calibrated. It is fixable, but a PITA to do.
You could pull the cluster out to see if the cable spins to avoid the possibility of spining it backwards.
Anyway, if all this is good, then you have a broken input on the gauge itself. It happens. They will collect condensation and rust out the springs and fall apart.