Okay we have a 2002 chevy 1500 silverado, a few months ago we started hearing banging in the so we thought rear of the truck but after some looking around we found a hole in the transfer case so we took it out and had it repaired but when it was taken on a test drive it would shift out of 1st gear and the speedometer stays at 0

We did find that one of the wires going to the (speed Sensor on the Transfer Case) wasn't getting power as it's supposed to but we can't find anything wrong with the wire.

All the fuses were checked (4) different places correct? but they were all good or at least we didn't see any fried ones
The ones that weren't getting power when they were in place we took out and sent power through and they worked.

There is also one pipe little rubber pipe above the transfer case that looks cut and we have the end for it but we don't know what it is or where it goes.

If you can help please comment.

 

The speed sensor generates the signal. Have you tried another sensor?


Allan

 

speed sensor produces the hall effect signal. if its bad it will not shift as the tcm and pcm dont see mph, new sensor is common and about 30 dollars. and if this does not work then look at the terminals on the connector see if they are pulled back and or spread open and not making a good connection

 

also the rubber pipe is for a breather vent, its supposed to be connected in line with the trans i believe not sure as i havent done one in awhile. but it is supposed to be conected to at least a check valve. if you call your local dealer they can fax you or print you off a diagram of the vent tube routing for free

 

oh okay wow Thanks everyone so much for all the answers i wasn't expecting that.
And I will be sure to try what you guys said. and like Joe and allan said the sensor makes its own signal I didn't know that. that could solver a few problems but still why would it have gone bad right as we change the transfer case.
I guess someone could have ruined it actually..

 

When you pull the sensor, check to make sure there is a reluctor ring on the output shaft and that it is tight to the shaft. Maybe the builder just flat left it off.


Allan

 

oh okay.
one other thing is there a way to test and see if the sensor is working or not?

 

Yes, a very good diagnostic scanner can read the sensor voltage.


Allan

 

okay so we changed the sensor (both of them) and tried it but the truck still doesn't switch. Anymore suggestions before we take it to a shop?