i bought 3 eletronic vss and non of them fit. my broken vss has a hole in one side wondering if they made mechanical t56s??? bought used did they make mechanical t56s?? can is there a way to go from mechanical to eletronic?? any help appreciated

 

Your posts seem to indicate you're going T5 to T56.
First, which T56? Camaro? GTO? Other?
In your new thread, you have no pics, no part numbers, and I am not sure what the hoke in the side looks like.

A Dakota SGIwhatever can be used to plug into a stock T66 reluctor style VSS, convert the pulses by a ratio, and feed an 86 firebird DRAC board.

You very likely do not have a mechanical speedo drive T56.

 

here some pictures of the vss that came out of the trans. bought 2 vss from autozone not one fit. supposedly it came out of a viper but to my understanding the viper didnt have a vss on the trans. ill try to get some pictures of the tail housing tommorow

 

If you mean, with provision for gear-driven speedo systems, no. Not stock T-56s anyway. Some aftermarket ones may be different.

Can't tell for absolutely sure what the thing in your hand is... doesn't look like a VSS though, looks a whole lot more like a "bullet" for gears that would go with a cable drive, with abuncha some kinda spooge all built up on it for whyever, maybe somebody just spooooged it all up real good and jammed it in the hole to keep the fluid from coming out. Of no use to you in any case.

The hole in the case for the stock VSS is in the wrong place for a speedo gear. It's pointed right at the place where a gear would go on the mainshaft (where the reluctor is currently installed on the mainshaft) instead of being off to the side like a gear of the types of VSS that were used in our cars, which also used gears, would need to go. Different people used to modify the extension housing for that; it involved building up the place with epoxy where the gear thing (like your speedo bullet for example) needs to go, milling out a hole, drilling & tapping the bolt hole for the retainer, and plugging up the hole in the stock location. I seem to recall that the holes partially overlap, such that you can't just use a welch plug or the like, butt I'm much too lazy to go out and crawl under my car and look. Jags That Run I know did it, and a guy that used to post on this forum named Alloy did (I have one of his that I got used in maybe 2002 or so). Haven't seen or heard anything from or about either of them doing it for at least 15 years, maybe 20.

You're lucky, you have a car with electronic speedo, so you can use the solution that jmd posted. Quite simple and effective. All you have to do is put the stock T-56 VSS for whatever transmission you have back in it, hook it up, program it to produce 1 pulse for every 4 that come into it for 3 sets of 4 and then 1 pulse for the next 5 (17 input pulses down to 4 output per shaft rev), and you're set.

 

https://www.thirdgen.org/forums/member.php?u=15464
he use to modify the t56 to use i think a th350 bullet and Vss gears.

 

Indeed: same one as the T-5, old 4-speeds, etc. Then when they first introduced electronic speedos in the 80s, the VSS was the same size and shape, and plugged into the same hole, and used the same style of gear drive although the driven gears themselves were different. Drive gears, on the mainshaft, were the same for both cable and electronic systems, which made it a pretty easy swap, back when you could still get the sensor itself and the driven gears.

 

I second Tuned Performance's recommendation for alloy. I have been running one of his modified mechanical speedo conversion for 7 years now.
A great guy to work with.