Isn't there a cable that goes to the tranny to control the speedometer?

 

There's no speedo cable. Only electrical plugs.

 

ok, wasn't sure. My buddy once removed his on his truck to save his miles

 

what a dirty *******! hehe

 

Most of the time this problem...

due to a faulty speed sensor harness or the sensor itself. The speed sensor is located on the tranny tailshaft. Can't miss it. It looks like a can that is slapped on the side of the tailshaft that has a harnesss lead coming out of it. You need to remove the sensor and set a voltmeter to the continunity setting. Place both probes on the sensor harness then rotate the sensor gear slowly. The voltmeter should show intermittent continunity as the gear is turned. If not the speed sensor is shot and needs replacing. If so then you need to check the harness for any corrosion or greasy buildup..Clean the harness and make sure it has a solid connection. If the harness is clean then you need to check the continunity from the harness that attaches to the sensor to the ECU making sure there is no break in the harness lead to the ECU.
Hope this helps!
MaxDoc

 

look at the speedo drive in the trans. i work at nissan shop and have come across a couple with gears worn on the drive. even found one the have bad trans speedo drive gear.