Odomerter working but speedometer not?
 

I recently sent my speedometer to fix/calibrate because the needle was not reading the speed accuratly. I changed the speedometer cable sensor, and still the same problem.

Speed is not accurate, but the odometer is working fine?? How?

From NH they said that they found nothing wrong with the internals of the speedometer.

So with new speedometer cable, verified wire continuity from sensor plug to speedo back, and “good” speedometer?

What could be the problem?
Thanks
IVan

Tire size? It’s not uncommon for speedometers to be slightly off from the factory. In fact I believe they (many auto manufacturers) make them optimistic for safety reasons.

What size wheel/tires do you have? How far off is it?

Jinx ^^^ :-)

Factory wheels and tires. Is not off, is jumpy and not accurrate or strady.
It is on the low side way off., If I need to got to more than 30 mph for it to start to move and then is on the low side and jumpy, not smooth.

If you have a buddy with a speedo you can borrow/swap to make certain it is not your newly rebuilt/tested speedo would be a good idea.

Here is another possibility, when my speedo was off by 10-12% it was due to a magnet that got loose, dropped off and was sitting at the bottom of my gear box. Once re-JBwelded on, she was good but 3 mph off :confused: but steady and note our speedos will not register until over 20MPH ( As I recall )

One more thing, you did check all connectors behind the gauge and in the tunnel are clean and tight?

I think is the magnet inside the transmision. I will put it on future things to do if I drop the engine.
Dam it. It was out for several months, but it never occured to me to be a internal tranny problem.

You don't need to drop the engine to remove the differential. Access to the side cover is actually quite good with the transmission in the car.