WOW! This thread is an AMAZING collection of misinformation.

There is NO FREAKIN' WAY that the problem is the transmission. You have an engine power problem. Fix what's wrong with the engine (I'm a trans expert, not an engine expert) and the trans will be fine again.

If I had to guess I would go with a plugged filter, either air or fuel, or a weak fuel pump.

 

How can it NOT be the transmission if it drops out of gear when it downshifts?

 

Fuel pumps are either good or bad these days, if it's bad your dead in the water, so that isn't the issue. Bad fuel wouldn't do this either. A dirty air filter won't cause an engine to not downshift under load.

OP said the following: "The downshift never happened. I kept pushing more pedal and eventually, at maybe 40mph, it downshifted, but still no power. Engine being held at around 2500 rpm. No power no matter how much I pushed. Down hill I was able to resume speed but as soon as the next uphill, same thing, no power, no shift."

"Truck hits 45mph max on flat ground."

"If I push my foot to the floor to really force a downshift, engine will rev freely up to redline with no resistance once it downshifts. If I let the rpm drop down, it will catch and lock back in. Now when I come to a stop the truck has a very lopey and rough idle and will stall once I come to a complete stop. In neutral and park the engine still has a lopey idle and is rough. Will possibly die at times. Sounds smooth and perfect when you rev it in neutral or park."

The description doesn't point to a fuel system problem or an air filter.

I'm still thinking transmission somewhere, whether TC or some sensor or sticking valve body component.

... HOWEVER....

There is one other possibility to look at though, check the catalytic converter/exhaust system. If somehow the CAT got plugged (also look at whole exhaust for bent/crushed pipes) the backpressure could build up. However when this normally happens engine temperature will also build.

 

No. Fuel pumps will go bad to the point it will let the engine run and accelerate and even drive up to a certain RPM. And on Fords the fuel pump modules are very common for going bad. I would really look into the fuel delivery.

 

I missed that. But all the other symptoms point to low engine power.

 

Mark is right, it's not the trans. It sounds like a fuel problem or even limp mode. Your engine (lack of) power is making the trans act funny.

 

Limp mode might mirror the OP symptoms....
https://www.ford-trucks.com/forums/6...limp-mode.html

The question is what triggered that mode then. OP says it's not throw check engine though he did disconnect battery. If that doesn't reset a "limp mode" what would?

 

Fixing the problem.

 

Could be a bad COP - feeling the miss under load versus when in neutral. Check the resistance of each COP and see if you have a bad one...

 

But he can't go over 45 (which is about the limit for failsafe/limp mode.) I could probably do about 90+ with a bad cop.

 

Since it was raining...could water have gotten in one of the spark plug holes causing a misfire?

 

Definitely, I did a write up and many posts on it.

 

Here is Brent's post on the "fixing water in the plugs"

https://www.ford-trucks.com/forums/1...s-the-fix.html

Hi Brent!!

 

I don't think that water would cause the truck to respond this way. Mid-trip you'd expect a hot engine would evaporate most moisture away. If the plug boot were perhaps cracked that's more likely how moisture would enter, but still with the high energy coils it might run rough but it wouldn't be the same as what the OP is talking about. However he can check that seal pretty easy.

Still waiting to hear what the verdict is though to the cause of his problems.

 

Here was the issue:







I checked it about 3 weeks ago. I've done a LOT of miles down dirt roads since then!