Have a 50 Olds series 76 with a flathead six and a slush box automatic transmission. What type of transmission fluid will be compatible? Sent from my iPhone using The H.A.M.B. mobile app
Original spec was called Type A, which was superseded by Dexron. There has been several versions of Dexron over the years, but any Dexron III/Mercon labeled will work good as Type A replacement. You won't find any earlier Dexron versions than Dex III at the store. I would not use a higher version because then you start getting into synthetics and lower viscosity, which would likely increase your leaking.
You can use Dexron III up to Type H(Type K is for MTs) for use in older Hydramatics that required GM Type A. Wikipedia has a good article on it. https://en.wikipedia.org/wiki/DEXRON#1949_–_Type_"A"_Fluid
An early Hydro. ain't a slush box... I ran mine on Dexron for a few years after I rebuilt it and then changed it out to Type F. Worked well with either one.
Not the same as Dexron, or Dexron III(Type F) Ford broke off and made their own various fluids for Ford designed transmissions back in '59. Mercon. Ford Type F can be substituted in a known slipping/dying transmission to 'make it go' a bit more, but it is aggressive and will cause harsh shifting in anything not designed for Ford Type F fluids. Even Ford doesn't spec 'Type F' in anything that requires 'Mercon' derivatives.
MM is right, Ford type F is a fluid designed for less lubricity. Back when auto trans were first being designed, Ford took the route to have the clutches not slip as much to minimize wear on the clutches. GM and others use the higher lubricity fluid and this allows the clutches to slip more for softer shifts. Either fluid is more of a hydraulic fluid than a pure lubricant though. For racing or higher performance street, many people use Type F fluid in their non-Ford trans to provide a firmer shift and less slip. It won't cause any reliability issues that I have ever heard of. Just the firmer shifts as compared to Dexron.
In the old days Ford fluid was more "heavy duty" and was preferred for racing or performance, or trailer towing even in transmissions that called for Dexron BUT you had to change all the fluid, preferably after a rebuild starting with an empty transmission. Today there are far more options, synthetics etc for heavy duty use. For your car use Dexron as recommended above.
I have a new case 12 of A if anyone in So Cal Orange County ...Inexpensive...If any care to come and get it.
I had C&O hydros in several of my cars in the old days and they always recommended the Ford type F trans fluid. I never had a problem with any of them. Most stock hydros could use a little firmer shift. I’ve run type F in my TH350s for years and again, no problems. Sent from my iPad using The H.A.M.B. mobile app
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