My speedometer works sporadically. When it doesn't work my odometer and trip meter also don't work. I have replaced all the wheel sensors and had the cluster checked. Also traced all wires and they're all good. Now I'm being told it is the trans output sensor, but my cruise control works when the speedo doesn't so doesn't that rule out that sensor? Of course most of those sensors are very cheap so why not just check right? Well the one for my Allison MT643 is $350.00, so I can't just dump that cost for a big ?maybe? What do I do now? Just to throw this out there I live in Pa so it has to be inspected every year and it won't pass if the speedo doesn't work. Any help would be greatly appreciated. I'm at my wits end with this.