80 Ford transmission oil

37 chief · Apr 5, 2009

About 6 years ago I changed all the oil in my 80 ford F350 trans, as well as changing the torque convertor seal when the motor was changed. I believe it has a C6 trans. I don't remember what type of oil I put back in, but if I put in F type instead of dextron which I was told is the correct oil would this have harmed my trans. Sometimes now when I put it in drive it takes a few seconds to start going. I always thought all fords used F type oil is the reason I may have put in the wrong oil. Stan

Anonymous-0 · Apr 5, 2009

Chief it sounds like you need to change the fluid and filter. I have a friend that built hotrod automatics for the drag strip for several years, and he also had a trans shop for those folks that drove normal. We sometimes talked about what would work fluid wise in an automatic, not trying to start an argument but I'd bet you'd be suprised what will work in an automatic.

Brian Jasper co. Ia · Apr 5, 2009

Using type F over dexron/mercon won't cause a delayed engagement. You could have a worn hydraulic pump, sticking valve in the valve body, mis adjusted manual valve, or extremely worn clutches and plugged screen. They don't have a filter. It is nothing more than a fine brass screen.
Using the wrong type fluid typically causes harsh shifts. Over time it could also attack the piston/servo seals. If it shudders when shifting, if the clutches aren't worn, they can begin to pit away and the material will end up in the valve body and take the whole trans out.
If you end up having your C-6 rebuilt, find out if it is a heavy duty or light duty. Light duty versions were put behind everything from the 300 six to the 400M engines. The 429-460 used the heavy duty version. If I remember correctly, the forward clutch drum has room for more clutch plates.

80 Ford transmission oil

37 chief

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Anonymous-0

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Brian Jasper co. Ia

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