[Christ]

Originally Posted by suspectnumber961

As far as I know...viscosity is more controlled with synth vs dino gear oil...meaning that when cold synth is thinner. One person claimed that after changing to synth gear oil...same weight...he could coast further with synth oil.

I had an '86 Escort that used ATF in a manual transaxle....thinking that using synth ATF with a good additive might work...but might be risky too.

Ford recommends the use of Mercon-based fluid in almost all their manual transmissions, with few exceptions, that I'm aware of. You're correct thinking that synthetic, as a rule, is more stable. I'm not sure this applies in a transmission as much as in an engine, but I can't really support that thought.

Using synth ATF that applies to the same specs as your original trans fluid will be fine on it's own. You can go to Ford dealer and get a 4oz can of friction modifier, but it's probably not necessary for the older trans?