I have a 1979 ford thunderbird with a fmx transmission and it won't go in any gear without a little throttle...does anyone know what it could be?

no one fixes those. they remove them and use something else

?

Or fluid level, but the best correction for a problemjatic automatic comebackin FMX is some C4

You can add fluid, service them, you can use additives, You can clean and repair the valve body but not in front of any Ford garage shop foreman I ever worked with. We even had trans specialists that would install parts in them and get paid, but no one would say that would fix them and have them stay fixed. you can do anything you want to your own car. But at today's prices, you might want to put the same money into a trans that you can improve and believe in. That's why our Ford swammy from the sixties we had as our Foreman when I was an apprentice, would roll the dumpster into the stall under the car and let them drop. Kinda telling all the apprentices not to believe they could affect the dealerships bottom line by making FMX repairs and then trying to run and hide.

I hope it is just something simple for yours, and you get another 8 years out of it.

Just thought of what he would say if the customer kept asking, does Fred make an authorized remanufactured unit? Is the labor paid if it has problems? Go into The Ford parts department and price one. If everything's covered ? Just keep ordering them each time till they run out of them, like the rebuilt holley.

In the defense of the car, I would say anything found during a cursory examination of adjustments, controls, hoses or even the wrong dipstick can make an alright transmission look bad