Hello!

I am not entirely sure if the kickdown on my 85 F250 (with 460) is working properly and wanted to see if this sounds right. If I am driving 50 mph cruising in 3rd gear then slow down to 20 and accelerate again, the trans remains in 3rd gear the entire time. Is this normal, isn't it supposed to down shift into 2nd gear while getting back up to speed again?

If I am completely stopped and accelerate normally, it will shift into 2nd gear at about 25 mph and then into 3rd gear at about 35-40 mph. So from a complete stop it works fine.

It has 3.54 gears also if it matters.

 

It will only downshift if you floor it. You have to mash the pedal all the way to the floor to force the throttle linkage to hit the downshift rod or cable. Cruise down the road at 30-40mph and then nail it to the floor, it should downshift.

 

Sounds pretty normal to me.

The kick down is a mechanical linkage that should operate as Dave described. There's a rod that's attached to the throttle linkage and then down to the shift linkage on the side of the tranny. Check to make sure you have one and it's hooked up.

There is also a vacuum modulator at the back of the transmission that I believe also controls down shifts and up shifts according to engine vacuum. There should be a vacuum line from the manifold vacuum tree at the rear of the intake (between the carb and firewall) down to the modulator. If you pull the vacuum line off of the modulator and there's tranny fluid in the line the modulator is bad.