Any idea as to where I could buy one? I have checked the FSM any anyone should work up to 1981 as they all share the same gear set . Have looked everywhere and I can only find the housing for the 81 but not the gear.. The part is just a source of leaks at this point, the silicon held up a few months but it finally gave and back to drips on the driveway. ( along with the o ring for the shifter level rod, but i ordered that already )

 

Do you just need the o-ring for the speedometer gear or the gear driven assembly with gear and o-ring?

 

There are two o-rings on the speedo gear that can cause leaks if they are faulty. There should be no need for silicone if both seals are working properly, and the gear itself certainly shouldn't be the source of a leak unless it's seriously damaged.

The main o-ring is on the exterior of the gear assembly/housing that presses into the transmission. The second one is less of an o-ring and more just a shaft seal that goes inside the housing where the cable connects. Atkins has both seals for sale last time I checked.


Edit: I think I may have read your post wrong. Are you saying that you're missing the gear and you plugged the hole with silicone to keep it from leaking?

 

Long story short, I pretty much mangled my original one because i reassembled it incorrectly I can't get the right bushings for the Original 79 one, but I can get the repair bushings for the late 79-81 style speedo gear,

 

For the entire assembly, I have the Original run style gear, which is brass, and Atkins does not carry the correct O ring or inner seal, in fact, no one does, I tried to make my own O ring and got the part stuck in the car. BOTH seals leak , I fixed it by applying silicone to the inner O ring ( only the inner side of the O ring, I wiped all of it off so the silicone would never come into contact with the rest of the housing ) . That seal failed and it is leaking again, Plus my speedo gear is chewed to all ****. I just need an entire new speedo gear assembly, I can buy the replacement bushings myself, they just don't fit MY early style gear and I advise people not to **** around using custom O rings, you will get it stuck, you will break the bottom part, and you will ruin your day. .

 

So I take it that this is on an early 79 transmission? Is it a four or five speed? I didn't know that there was once a brass speedo gear in these cars, so unfortunately I probably won't be of much help here. The oldest transmission I've touched is a 1980 5-speed.

j9fd3s might be your best resource for crossing numbers and going through the fiches on that one. Hopefully he'll chime in when he gets a chance.