speedo broken, need help

hey guys its been a while since ive tried to invoke the help of this forum, but my speedo is broken. ive tested the cable, and the instrument cluster, the only other thing i could think of is the gear thats in the tranny. now it looks like the housing for the gear comes off, but i havent really tried to take it off. any help, anyone could offer, or maybe someone with a spare gear off of a tranny they are willing to sell would be hlpeful.
thanks for listening.

Would that little brass part that sits inside have anything to do with this? I haven't paid much attention to our speedo's (electrical and mechanical) but just noticed that part comes out fairly easily...

it does come out rather easily, i just went and checked. problem is i called around, and autozone says dealer only. i called dealer, they say back order, no longer in production. So unless i want to drive around without a working speedo(bad news in norfolk,va.) i have to find someone else who has a spare tranny who could sell me the part, because im sure not going to find it in the junk yard.