So I replaced the tail shaft housing on my tranny. I used the speedo gear from the new tail shaft housing. now my speedo needle isn't as crisp as before. I want to put the original gear back in the new housing to see if it resolves the issue.
I want to know if I will lose trans fluid if I remove the gear with out draining the trans.
car is an '85 5spd GSL.

thanks

 

In short, Yes.

I've never cracked open a RX7 Tranny (yet) but all the other Mazda transmissions I have would say yes, you would lose fluid. And they appear to have the same basic construction on this level.