It's a little more complicated than that. On the side of the trans (actually the differential housing) there is what appears to be a freeze plug. Immediately behind that is the back side of the ring gear (i.e. the side without teeth). It would be possible to put some kind of sensor in that hole, but the hairy part is that you'd have to put something to count (teeth, magnets, etc) on the ring gear carrier. There is nothing in place. This is very similar to electronic tach applications used in other cars, BMW for example uses a pickup on the diff housing to read the ring gear rotation. In the "other" application of the DMC Renault trans recall that the ring gear is flipped over. I suppose that there is something installed in that application to drive the speedo, but I've never taken apart a Fuego trans to see what. Honestly it would be easier to put a transducer on one of the inner CV joints (like many aftermarket cruise controls). Dave S --- In dmcnews@xxxxxxxxxxxxxxx, Steve Stankiewicz <protodelorean@xxxx> wrote: > This was the first I'd heard of there being an unused > speedo output on the tranny. Can someone point me to > it? (Anybody have a picture?) I will be using an > electronic speedo on 02650 and would rather mount the > sending unit to the tranny rather than the front > spindle. I'll happily post the process/results on the > website. > > Thanks > > ===== > Steve