I have two, one in my 64 Galaxie and its fresh. One that is in my 93 Notch, its used. My fresh one went together and got syncromesh. The used one has been in the coupe and has a red fluid it in. Can I drain and put the syncromesh in or whats the deal?

No clue what fluid is in it for its used and I kept that fluid in there for the past 30,000 miles....

Let me know the best way to approach this.