mix conventional tranny fluid with synthetic?

[94f450sd]

can i do it or does it have to be synthetic?

 

[BIG JOE]

For piece of mind ? I wouldn't do it Rich.

It's one of those... If in Doubt ? Don't... deals.



Joe

 

[DaveBen]

Regular and synthetic oils do not mix well, so DON'T do it.

Dave

 

[94f450sd]

ok i wanted to make sure.my thanksgiving day escapade fubared my converter but it never dawned on me to check the fluid till last night .still havent checked it yet and i dont know if any of the parts stores sell synthetic atf or not,never looked for it.truck still runs and drives but i gotta baby the crap out of it to get it moving in drive.if i give too much throttle the converter slips and it dont move.seems to be a bit better in my wildman tow program though.if the converter will lock up its fine,but if it dont lock i still gotta be very light on the throttle

 

[JimmyDee]

Regular and synthetic oils do not mix well, so DON'T do it.

Dave

Everything I have ever read about this situation including the Webb sites says its OK to do. Some oil companies even blend regular and synthetic and call it a blended oil or synthetic blend.
Jim

 

[94f450sd]

well we are talkin about a tranny that cost me somewhere around 5 grand when it was all said and done and in the truck.i want a definitive yes or no.i already done enough damage and really would like not to cause anymore.im not even driving it unless i have too.

 

[trackspeeder]

Yes, they can be mixed.

 

[94f450sd]

Yes, they can be mixed.

are you positive?i just checked the fluid and there aint a drop in it.id rather dump cheap stuff in it and save it than replace it.

 

[shhorn68]

I have a good friend that helped formulate the synthetic fluids that are being used in several of Ford's transmissions and she advised against mixing the various fluids. Mixing fluids can drastically change the viscosities. This, in turn, can affect the way the components, of the transmission, respond.

I am no expert on transmissions but I think if the viscosities are altered very much it could definitely be a big piece of the puzzle in your situation.

 

[JLDickmon]

well, I'm not a fluid engineer so I can't tell you about what viscosity rating Ford's ATF is..
but, all other things being equal, yes you can mix synthetic and non-synthetic fluids...
if you couldn't, you wouldn't ever have such things as synthetic-blend engine oils, ie., Dura-Blend, SynBlend, etc.

AFAIK, the only vehicle manufacturer that specifies synthetic transmission fluid (outside of the proprietary and obligatory BMW, Mercedes, and other high end rockets) is GM for the '08 and later RWD trucks.. Dexron-VI..

I bought a 5-gallon bucket of Dex V/Mercon at NAPA for right about $90.

Synthetic fluids are made from esters and have equal and uniform molecule sizes.. the viscosity is a measure of "thickness" and the Mercon-V is an additive package..