I have a P35 (Ford) with a E040D Transmission. I stopped for fuel and when I pulled out the speedo. started bouncing all over the place and the transmission began shifting all over the place. The speedo stopped working all together. I had to shift the transmission manually. Any idea where to start?

Thanks
Leon

My guess is that there is a vehicle speed sensor that both the speedo and the tranny rely on to tell what is happening speed-wise. That sensor failed or the wiring to/from it shorted or opened some how. You probably need a pro at automotive wiring to diagnose it.

Gary is probably correct but on one of my previous motor homes, I had problems similar to what you describe and it ended up being voltage from the battery just low enough to cause tranny problems but nothing else. I'm still not sure how that worked but a new battery took care of it. Go figure.