Electric speedo to A727 TorqueFlite.

[Brandy]

2002 Audi A4 electric speedo to 1973 727. Solutions??

 

[kiwigtx]

Hall effect drive at the transmission?

 

[5.7 hemi]

Most electric speed senders are 3 wires, red, black and white as the signal. You can pick one up on eBay for 30 bucks. Worth a shot.

 

[Brandy]

Hall effect drive at the transmission?

" What chu talkin bout Willis?"

 

[Brandy]

Most electric speed senders are 3 wires, red, black and white as the signal. You can pick one up on eBay for 30 bucks. Worth a shot.

Do I need to know how many pulses the speedo is?

 

[Brandy]

Is it a device that goes on the tranny at the speedo hole or what? Since there's no cable involved there must be a trans speedo cable output device at the trans that converts the cable drive to pulses?

 

[Brandy]

plus, how many teeth on the cable drive in the trans ? I see so many different counts? What is the correlation to 30,40,50 teeth to MPH?

 

[5.7 hemi]

Tooth count doesn’t matter, you need to know what pulse range your speedo is, most senders will do a variety of pulses, it will screw into the trans where the old cable was and GM/Chrysler used the same size (7/8) if I remember correctly.

 

[5.7 hemi]

https://www.summitracing.com/parts/...MIyNnqru6k4AIVhLfACh0RnAOIEAQYBCABEgJDh_D_BwE

Here’s an example.

 

[5.7 hemi]

You may need a box from Dakota Digital, again depending on what your speedo is.

 

[Brandy]

I sent them an e mail about it...

 

[Brandy]

So, I found out that it's a VSS signal that's needed. It apparently has a sensor that reads off of a magnet ring on the front wheel input or output shaft.

 

[Brandy]

Or should I pop that speedo / gage cluster out and swap in analog units?

 

[Brandy]

This is what it looks like..

 

[5.7 hemi]

Me, I’d get a set of electrical gauges that uses a electronic speedo, and move on. But if your doing something totally custom, dig deeper to see if a speed sensor could run it. To test, use your cordless drill to turn the sender and see if the gauge moves.

 

[5.7 hemi]

You could send that bezel to Dakota Digital and they will build ya gauges and then your set.

 

[kiwigtx]

" What chu talkin bout Willis?"

As an example....here is an electric converter for a speedo drive
https://www.jegs.com/i/Classic-Instruments/087/SN16/10002/-1

I connected a Hall effect speedometer drive in a HotRod a few years ago. I needed to initially guess at the dip-switch settings to get a reading, then a 2-car drive test with a known good speedometer. Then I was able to calculate the difference in readings, and I got the HotRod readout bang on first adjustment.

 

[Brandy]

Okay. This is the speedo gear and cable from the transmission i'm using. Where does that thing plug into this set up?

 

[Brandy]

So, Dakota Digital tells me I need one of these output gears for the sensor to screw onto and the distribution block/signal adjustment.

 

[kiwigtx]

Okay. This is the speedo gear and cable from the transmission i'm using. Where does that thing plug into this set up?

To me it looks like you need the correct pinion for the speedometer drive already inserted in the transmission. Then the new unit screws onto where the cable would normally go - and from there the cables carry the signal to the speedometer on the dash. Conversion or compatibility of that signal is the next task to figure out. Have you any factory manuals or information about the Audi speedo output signal?