ryan10

Hey guys, my speedo reads way off. Today i replaced the speed sensor in the T-case and its the same. what should i check next? when my speedo says im doing about 42? its really 65, and the truck shifts OD when the speedo says 32
thanks.

97catintenn

Either follow the wires from the sending unit and clean the connections in the wire harnesses along the way to the gauge cluster, and clean up the ground going to the sending unit...or run new wires of the same gauge.

97catintenn

I think that this will help, because when I replaced the wires on my sending unit, I used a thicker wire that what the spec called for...and it caused my speedo to read slower.

I'm not up to speed for the correct terms when it comes to electrical, but I think the lower speed readings have to do with resistance or the ability to carry a specific frequency, and your old wire can no longer do that...But I could be wrong, I'm just offering advice from my experience.

ryan10

OK, so the reason it reads slower is in the wires itself?
thanks for any help.

97catintenn

It caused mine to read slower. Either that or you need a new gear in the VSS (speed sensor) to correct the speedo.

ryan10

I have replaced the VSS, and the speedo is still off. where are there any grounds i can check. i followed the wires back and did not find any grounds. where should i look for stuff like this? any grounds in the gauge cluster itself?
thanks.

ryan10

Also, the inside piece that the square tube on the VSS goes into inside the tranny, could that be rounded off somehow or something? my VSS goes straight into the t-case. is this how it should go, or should there be something else outside?
thanks.

ryan10

Ok, well here are some pics of my VSS. the truck is a 93 auto 4x4. Am i missing anything?

97catintenn

If yours is suppose to look my 91.0 model, then yes, you are missing another little do dad that goes into the t-case.

Here is mine.

wannadiesel

Yes, he's missing the adapter gearbox.

97catintenn

I don't know where it is supposed to ground to. Maybe under the hood to the firewall. My speedo was bouncing all over the place, and I ran a new ground and that steadied it quite a bit.

Next I ran a new wire, a thicker guage...and that made it steady, but it read a slower speed that what I was actually going.

In the guage cluster, you can just remove the wire harness and clean the connectors/recrimp them to make them tight again, but thats about it....as far as I know.

I didn't look too far into the factory wiring. I just jumped the gun and ran a new ground and new sending wire to the gauge cluster.

ryan10

Ok, where can i get the adapter gearbox? is this whats causing it to be off?
thanks.

wannadiesel

Dodge. Yes, it's your whole problem.

ryan10

Ok, any idea what they cost from dodge?
thanks.

wannadiesel

Around $80.