Good morning from the great white north. I just got my barnfind 63 f-85 running the other day and took her on her inaugural journey to town. It ran and shifted great until it started to get hot. Then it shifted erratically, motor started missing and I had to use the gears manually to get it to move at all. It has the "slim Jim" roto hydramatic trans in it, and I'm pretty certain it and the motor were just rebuild before I got the car--It was an estate sale. I've read that this is not a great trans and that requires type "a" trans fluid which no longer exists. What would be the best substitute for this trans?

Thanks for all your help.

Dallas
Nelson BC, Canada

 

Dexron III / Mercon is the type to use today. Do not use any "synthetic" fluid .