So I'm at wit's end with this speedometer gear issue. My OEM one leaked and trying to fix it, I damaged the OEM bronze gear which led to some funky speedo behavior. Carl was kind enough to give me his gear and that fixed my speedo, but I'm still having leaking issues because I can't source the collar. The external AND internal O ring is NLA, and no one makes the correct size, my attempt to make a custom one resulted in me getting the bullet stuck and damaging my gear. For late 79 and 80+ Mazda switched the design of the collar and I can get the correct internal O ring and external O ring. I found this collar 101117442A ( it is a collar, that fits a few Mazda cars including a 89-92 rx7 automatic, Jim Ellis Mazda says it supersedes the other part but can't find it anywhere else ), I need 101117442. Does anyone know where I can obtain this part?

 

So I finally tracked the parts down after much research.
The gear and roller pin were gifted to me by @Carl almost a year ago which was the hardest part to find.
The collar and gaskets were bought from mazda.
My final question is what direction does this gasket go ?



Does the Flat end face towards the trans or away from it ?

 

The flat side faces outwards, away from the transmission just like any oil seal. By flat I'm referring to the bottom of the "U" shaped profile of the seal, so the side that is one continuous section, not the two "rings" separated by a channel - mentioning this as both sides could be interpreted as "flat". Normally it's easy to just say "the side without the spring", but those seals don't have one .

 

I figured . I tapped it in with flat tube and it slid down nicely and got stuck there .

 

Can these be 3d printed?

 

The gear itself probably could be, but not the other components.

 

You can build your own , the only issue is you need the gear and if you have the gear you probably have the rest of it .
I have no idea how to take the gear apart though . Maybe you can make a 3d part that's all plastic but i don't know how strong it would be.
If any one can source us the GEAR you would be able to build your own . The miata one does not work BTW , the threads are pitched the wrong way.

No one has this part , i have asked high and low and found one guy selling me a broken one for 100$ but it was the old school one.

 

I just replaced the o ring and seal when I did my clutch a few months ago. There is a pin you have to drive out, and then the speedometer gear slides right off the shaft it rides on.

 

The gear gear or the gear with the shaft? I

 

The plastic gear driving the speedo cable

 

so you can separate the gear head from the shaft ?
I know you can remove the gear with its shaft by removing a pin from the assembly but not the gear from the shaft.

 

I apologize I think you’re right. The shaft is pressed into the gear isn’t?

 

Yes sadly . I can't find it ( the gear and shaft) anywhere :/.
The messed up part is the fact we can get the miata gear in 17 teeth but it has the gear pitch going the wrong way .

 

The oring and the seal are available through atkins rotary. https://www.atkinsrotary.com/store/7...8-60-8166.html
I think if you messed up the gear you can use a gear from a fc. Just would have to use both gears because it has a different pitch.

 

The outer seal does not fit the original design . If you have a early 79 or 80 rx7 you have the old design , those seals don't fit. Atkins says ALL 79's do but they are wrong.I'm a bit upset at them right now over another issue. Very disappointed .