I have a 2003 Ford F150 Lariat extended cab, while going down the road it will begin to skip and buck a small bit and the speedometer flickers back and forth from the 0 mark to the proper speed I am at. It seems to not matter what RPM or speed I am at it just randomly has a fit then goes back to normal. It tends to do it about every 5 minutes. It sounds electronic to me but Im not all that sure.