does anyone have experience with swapping out the cable driven speedo to the electronic ones. I have and 84 Z28 and hate the cable kind and would love to swap it out for an electronic one.

Please advise me on what is involved and what parts I may need plus tools also. and if anyone has done this can I see come pics please

TIA

 

If you want a stock electronic speedo you're out of luck. There's nothing that will replace your mechanical one.

 

check the tech articles on here.....there is an explantion how to do it under miscelaneous modifications...its for a firebird though i dont know if it is the same....should be

 

....OH Yes... Been there, done that! Swapped out the mechanical speedo in my 87 IROC and replaced it with an OE electronic speedo cluster from a donar 91Z28. Brother, this was not a weekend project as it involved replacement of the dash, all interior wiring, including the newer ECM and finding the correct vehicle speed sensor.... If I had to do it all again, I'd order the Covan's Classic instrument package and the hall unit for the speedo. Pricey? Yes but so was my conversion project. Worked out to cost about the same in the long run.

 

How does a person figure out what kind of VSS they need? I went to the parts store and they have three different models for an 88 T/A with a 700R4.

I have all the hookups and dash for an electric speedo, but someone swapped in a 700R4 that is currently cable. What do I have to do to get it to work? Change the tailshaft+VSS as a unit, or can I just get any VSS for a 700R4 and it'll work? The three different models look the same to me, does it matter?

Hopefully someone can elaborate on the issue, it's driving me crazy like it is now.

 

If I had to guess, the three different ones are the same VSS, but with different driven gears on them.

 

As far as tailshaft compatibility goes, is a cable driven the same as the electronic?

 

Yes

 

Check one thing before you start... is the yellow and purple wire from the ecm to the vehicle speed sensor tucked up under or around the transmission? A nasty hunt for these critical wires but... you gotta look. If your ta was originally equipped with an electronic speedo, they should be there (hopefully). Then..

Start with the vehicle vin number. This tells all. Write it down, call or go see the GM parts dealer. They can pull your exact vehicle up and tell you precisely what the correct vehicle speed sensor part number is. Then, order it from them or your favorite parts supplier.

The drive gear in the rear trans tail shaft is the same for cable or electronic ss. When you pull the cable driven unit out, look to see what the color of the plastic drive gear is (do not confuse it with a driven gear, which is the speed sensor gear). It should be red or grey. This will help you to select the the driven gear for correct speedo function. Also, you will need to know the rear end gear ratio and your tire size. You can do a search for more information on these topics.

Good luck

 

I think I saw an electric speedometer adapter in summit. All it does is hook up to the speedometer cable and then it has wires to wire up the speedometer. Can't get any easier than that

 

Thanks for the replies.

I did alittle more searching and came up with this link : TCI AutomotiveŽ - Speedometer Gear Tech Information


The above is very very helpful in finding the right gear you need. I now know that since I have a red 17T drive gear, I will need a purple 43T driven gear on the VSS. I have 3.27 gears, and very close to 26" tires(metric size). Thanks for the help all.

 

Your one the right track but, be carefull. The TCI gear chart lists driven gears and part numbers that may not be compatible with electronic vss'ers.
I have the same set up as above and needed the light blue 45 tooth gear for near correct speedo. Check with your GM parts dealer or do a search for electronic VSS gears. Many others here on the board have posted the information (correct part numbers).