What kind of tranny fluid for a c-6 - 1969 f250
 

What kind of tranny fluid should I run in my 1969 f250 with the c-6? When I bought the truck the fluid was changed and dexron was used. The tranny slips going into 2nd gear. Should I drain it all and change it back to f?

There's those that will tell you that you should run Type F (Ford's recommendations at the time the truck was produced) no matter what. It's my belief that if the tranny hasn't been rebuilt recently, you should have Type F in it. If the tranny has been rebuilt recently, then Dexron will be just fine. The reason I say this is because the materials used when building today's clutches and bands are compatible with Dexron.

If your trans is slipping now, it may already be too late. You could try draining the Dexron out of it and putting Type F in, but the band and the clutches are already impregnated with Dexron and if they have been slipping for a while, then they are most likely glazed and different oil may not help. How is it from 2nd to 3rd? You might try adjusting the band and see if that makes any difference.

Good luck-

Joe

I had the same problem. I had someone dump dexron into my tranny, and it slipped. I was told to change it back to type F and it worked. Seems to use more fluid, but the type F did the trick. Just drain the torque convertor also, and make sure as much fluid comes out as possible. Good Luck -Fatty

Dexron will foam at ford temps..and pressures... If you didnt try to hot rod it ..you should be OK..

Always use type F with the ford trannies...it has an anti foam agent in it,so the fluid stays as a fluid and not Bubble's... Russ :-X22

I ahve a 79 with 242K. Original trans. It was my uncles. He used type F so I kept doing it too. Still works fine. Changed fluid every 25,000. I have been told B & M makes something called "Trick shift". Sold in Pep Boys. Also supposed to work well, but pricey.