Engine/Transmission (1994 - 1998) Speedometer input data for 5-speed

[cfarrar]

I'm planning to add an auxiliary transmission to my truck and have done a little searching to learn how the speedometer gets speed information. Since the NV4500 speedometer would not send the right information all of the time with a variable ratio behind it, I was thinking of conditioning the output from the rear differential abs to be the speedometer input. I called a local transmission shop to ask what type of data the speedometer uses and was told that, unlike most manufacturers, Dodge used the NV4500 speedometer sensor output up to 20 mph and the rear differential abs signal above 20 mph. Can anyone confirm this?

 

[MAllen]

that's not correct. My speedometer wasn't working at all & when I changed the rear sensor on the axle, it worked again like it should.

 

[CRWilliams]

There is no sensor in the trans. (or transfer case) in my 98. The computer uses the signal from the rear tone ring to interpret speed. You should be good.

 

[cfarrar]

Is there just a switch in the transmission to prevent starting in gear?

 

[Bob4x4]

Is there just a switch in the transmission to prevent starting in gear?

Clutch switch... ... ... .....