I have a 95 civic. The speedometer works intermittently, sometimes jumpy. I have learned it isn't a cable. Is there a sending unit that goes bad that can be replaced? I unplugged the wiring for it and removed two bolts under the connector on the transmission, but it refused to come off, if anything does come off. I'm afraid to put too much force on it if it isn't supposed to be removed. Any help is appreciated. John