How hard would it be....

[dpuckett]

I have been having a heck of a time finding a speedometer DRIVE (goes on output shaft) gear for my 2wd Getrag. So, I was wondering, how hard would it be to run the speedo off the rear axle? I know the truck this axle originally came in had this set up, which would lead me to believe the sensor is still in decent shape. Besides running the wires from the transmission to the rear diff, and coming up with a connector, what else would I potentially need? I figure something to correct the voltage would be required. (?)



Thanks,

Daniel

 

[CrewCab]

I have been having a heck of a time finding a speedometer DRIVE (goes on output shaft) gear for my 2wd Getrag. So, I was wondering, how hard would it be to run the speedo off the rear axle? I know the truck this axle originally came in had this set up, which would lead me to believe the sensor is still in decent shape. Besides running the wires from the transmission to the rear diff, and coming up with a connector, what else would I potentially need? I figure something to correct the voltage would be required. (?)



Thanks,

Daniel

I guess this depends on the type of sensor in the rear end. The one in the transmission takes a low noise ground from the pcm and pulses it using a magnetic reed switch and 8? magnets rotated by the output. Therefore, it is not a true ac or dc electrical signal (but rather a pulsed ground) and might be hard to match with a different type of pickup.

Terry

 

[pepecat]

you should be able to find one, however that gear is a plastic one. The one on the tailshaft housing of my spare 727 is metal, and a different part, one piece deal.

 

[JLEONARD]

I wonder if a low budget GPS would be cheaper. . it would be easier for sure.

 

[CrewCab]

I wonder if a low budget GPS would be cheaper. . it would be easier for sure.

But then the Cruise won't work as it uses the same signal.

Terry

 

[dpuckett]

I may start calling around and asking for a 20 tooth drive gear, with x-ID and y-OD.



Thanks for the replies so far.



pepecat, is the gear on your 727 removable? Or is it part of the shaft? I would not be against using a metal gear if I cant find an alternative.



-DP

 

[cerberusiam]

how hard would it be to run the speedo off the rear axle

Can be done. Has been done. IIRC, it used the ABS sensor for a signal then tuned it for what the speedo and ECM wanted. Pretty slick setup with an adjustable box to compensate for tire size. I suspect it was a custom built job though. If you like to play with electronics it would be relatively easy to do.