Re: tranny fluid ?

Posted by Owen_Dyneto On 2009/5/4 22:15:06

I think you'll find some mixed experiences here. Type F and Type FA are claimed to be the closest to what was originally used in Ultramatics, Type A. My own experience is that I got occasional direct drive "groan" until I switched from Dexron/Mercon III back to Type A and 15,000 miles since have been problem-free. Others who claim to have insight into the fluid composition say that Dexron/Mercon and others except Type F and FA contain slip modifiers which enchance smooth shifts in modern units by allowing clutches to grip gradually, and that this would be contrary to what you'd want in a transmission like Ultramatic with a direct lock-up. Can't say this is true or not, just that Type F solved my problem.