Yup,know the odo is mechanical. I've just installed a new one as the last one wasn't ticking up the miles, despite speedo working. Need to set the odo with the PCM-stored digital figure which I had read years ago when I took it to local Dodge dealership, which closed recently, leaving no shop anywhere near me that is equipped to plug in to an old Dodge PCM! It'd be great to just plug my laptop in with a suitable connector and read off any PCM data after installing suitable software.....and not having to travel anywhere to get ripped off by a co. that can do it, or have to buy my own ££££DRB