Nissan Repair: speedometer not working, tight wad, hose clamp

Question
Hi Von,
I have a Nissan quest 99, whose tachometer was not working for a while but recently the speedometer is not working and the dealer told me that this could ruin the transmission since the car is unable to sense the speed and so it might just start in 3rd gear. Please help. Could you please also suggest what the problems could be and what needs to be fixed. Also recently we had the overheating problem after which the speedometer stopped working. the overheating problem is resolved at least for now after changing the thermostat and flushing the coolant. Although we can still smell the coolant burning on the engine and were suggested that it might be due to a slow leak from something around the engine. Could these be related.
thanks a lot in advance
Neeru

Answer
Neeru,

Yes, the speedometer is what tells the computer when to shift the transmission.  Being the tight wad I am I would go to a wrecking yard and get one that way.  The dealer is right about the computer sticking the transmission in third and it will eventually burn out.  Get the speedometer repaired or replaced soon.  Now, the problem could be as simple as the speed sensor on the transmission.  You probably have a loose hose clamp or a pin hole leak in a hose.  The engine is pretty good when it comes to gaskets unless someone has done a replacement on one and did it incorrectly.