RX-Midget

Does anyone know if the speedometer sending unit from a 3rd gen can be swaped into an 2nd gen trans? The 2nd gen uses a cable driven speedo and these outputs that bolt to the side of the trans:



Does the 3rd gen sender look like it mounts the same way?

I'm trying to get a Autometer electronic speedometer to work with my car and I need a sending unit to mount in the trans. I hope that Mazda keep the design the same as they did for all other RWD cars they made.

Thanks,
B.

Wargasm

Brian,

I just happen to have my 1993 trans out now As I'm sure you know, it uses an electric sender... it attaches with one bolt to the rear portion of the trans up near the shifter but this is on the opposite side of the transmission as on a 2nd gen.

Do you need measurements? Pictures? Want to drive over to Rockville with your extension housing and see if my 3rd gen part will bolt in proerly? Let me know and perhaps I can hook you up!

Brian

RX-Midget

Thanks Brian!
Can you give me a measurement of the diameter of the unit where it goes into the trans and also the length from the mounting tab to the end of the gear?

That would be awsome if you could. I'm kinda in the middle of welding and smoothing some sheet metal out on the Midget right now (good-bye backup lights!) so I can't come down today.

oh, and can you also count the number of teeth on the gear? It should have more than most WV families have combined...

later,
Brian

Wargasm

o Number of Teeth: 23
o Diameter of body entering tranmission: 28.0 mm
o Height of gear: 14.9 mm
o Diameter of gear: 24.5 mm
o Face of mounting tab to top of gear: approx 52 mm -- This does NOT include the tip of the shaft and snap ring which would add a slight amount, this is to the top of the plastic gear only.
o Face of mounting tab to the external end: approx 45 mm -- This represents how far it sticks out of the trans.
o Total overall length: approx 97 mm

duckyjp

I am interested in this as well because I believe mine has failed. Do you have any pics? Thanks!

Wargasm

1993 Speedo Drive Unit

RX-Midget

Brian - You da man!

Thanks for the specs. I'm off to have a nice dinner out, but when I get back I'll check those dimensions. I'm stoked cus the pic looks like it is the same design

duboisr

See how the shaft is off center for crush adjustment, maybe your teeth were not touching. You can test the generator to see if it puts out. if it does then readjust the gear crush. just a thought. if the teeth are bad on the generator a new one can be made. The gear comes with the generator only and cost $160 ,one can be made for less.

RX-Midget

duboisr - I'm not having a problem with a sending unit, I just want to use a 3rd gen sending unit to replace a cable driven unit so i can run an electronic speedometer. There is no adjustment in any of the units. The shaft is off center to allow for different size gears which makes it easy to swap. See this list.

Brian - It looks like it should fit. Only differnce is my gear is 16mm tall and the overall is about 1mm differnce (due to gear size differnce).
Very cool! Now I just need to find a working one out of a core trans...
Thanks again!

later,
B.