Testiment to the 904 Trans

I have been slowly refurbishing my '66 wagon that spent 25+ yrs in the Texas Desert. One of the items I noticed just moving the car around my larger circular driveway was the transmission was slipping when cold and I could not tell about upshifts as I did not have enough driveway to find out.

Finally, having got the brakes squared away, engine running well I trailered the car to a local empty school parking lot. After just a few 1-2-3 shift (the first couple were pretty choppy) it started shifting perfectly!! I could not believe it?? I wanted to get it warm and through the gears before changing the fluid/filter so I knew what I had.

Now, I'm wondering if I should mess with it at all? It will not get serious drive time...just putt around for ice cream etc. But it sat so long the fluid has to be severly degraded. I'm thinking of just draining pan & changing filter...leave torque converter with it's fluid...so there is a mixture as I believe straight new fluid will take out what remains of the clutches. Anyway that's my plan so far.

But man, between the trusty slant six and the 904 no wonder you couldn't kill these things back in the day...