What am I missing here?
Changing electric VSS to a mechanical type on a 89 case. Best combo for tire height is 17/34.
Got a new, correct housing (plastic) for a 34T driven gear. When checking the gears installed, these barely touch and slip most of the time.

 

Everyone as stumped as I am?

 

What's your question? Is the speedo not working or is the speed reading fast/slow?

 

Gears are not fully engaging, bearly touching and slipping, so it won't work when installed.
It's like the diameter of the driven gear is too small eventhough the cover is the correct one for the gear.

 

You're talking about the little bullet/cap thing that the small gear goes in that hooks to the speedo cable, yes? Is it pushed in/seated all the way? Probably a dumb question but they can get a little tight sometimes.

If it's installing right but still not working try buying one for a TH350 automatic transmission. That's what I put on my T-5 and it worked perfectly. Plus they're a metal housing so it just seems stronger.

 

Th350 driven gears are totally different size (much smaller), so that won't work.

I can try to attach the speedometer cable and see if pushes the gear into the mesh, although I never had this problem before.

 

No joy with cable attached...

 

Maybe you're working with something different, all I know is that you can take the mechanical speedo gear housing and gear off a TH350 and bolt it directly onto a T-5 with no issues and your mechanical speedometer will work. I did this.

The driven gears are the same size.

If you're trying to re-use your electrical driven gear it will not work though as the electrical speedometer driven gears don't have the tail shaft on them that connects to the mechanical speedometer cable.

Here's some backup:

https://lugnutz65chevystepside.weebl...binations.html

 

Thanks for your help, but I'm working on a 700 and that's apples and pears.

I'm converting from electrical to mechanical, all parts involved.

Electrical speedo doesn't have a driven gear, it works by the hall effect created by a steel drive gear.

 

AH! Yes it is. That is information that would have been helpful in your original post. Alternatively you can also fill out your profile info so that your car's info populates under your name. It will vastly help people trying to help you. Good luck!

 

Haven't touched my car in years.... working on different rears and transmissions all the time

 

I doubt it.
So you got a wrong part or 3.
incorrect gear mesh is either a wrong diameter gear (there are other apps with a 34 tooth gear, and others that take a 17. And with out pictures of the gear(s) / sleeve / mesh, what would you like help with?

Look at the sticky with 700R4 speedo gear PNs. Google your heart out to compare to what you have, and see if you can figure it out. If you can't, post pictures.

 

No need to doubt a mathematical calculation:


Closest will be 34T driven gear using the most common red 17T drive gear.




Got the light green gear, correct part nr and the correct housing.


So, I know there is a problem with mesh interference, the question is why/how.

 

what did you do with the electronic vss? If you still have it would you be willing to sell it?

 

Sure, just not sure if you're willing to lay the coin for it, including shipping from overseas/the Netherlands where I live....

 

Is it for the t5 or 700r4 trans?

 

700r4