Before the transmission let go I was thinking

“When a Ford is running this good something is going to break”.

It did and I had it rebuilt by experienced tradesman, recommended by people servicing my other vehicles.

Yes the battery had been disconnected but after a weekend of mixed driving it sure wasn’t the same performance as before the “build”. The engine runs well, idles as good as a 4.6 is going to but feels as if it’s under load and sluggish while driving.
I have always shut the O/D off when I start my truck and only engage it at road speed of 60mph or higher. The transmission seams to shift to soon through the gears and will hold onto second pulling away from a complete stop, it’s sluggish and has become a pig on gas.

Before the build, O/D off and coming into a hill I could “feather” the gas pedal a little and the transmission would shift down, cresting the hill I’d lift slightly on the gas and it would shift back up into the next tallest gear. Now, to make it do the same I gotta pretty well send the pedal to the floor and drop the vacuum needle to “Zero” before it’ll shift.
In Canadian gallons, my numbers will differ to yours. Was getting 15-17mpg city 22-23mpg on highway, now 17mpg HWY and maybe 12mpg city. This engine grooves in at 2100 to 3000 rpm, I engage the O/D at 2100 RPM. and 65mph.

I've used a vacuum gauge for years and know where the vacuum would be at what speed and engine load, it appears now as if the engine is under load “pulling” all the time. An example it’s like running an empty truck verses one loaded with say 12 - 24” square patio stones in the bed. The engine is well tuned, has a steady vacuum at idle, pulling away in traffic it’s just sluggish, not really dead but lacking in anything it had before the rebuild.

There is no engine or transmission codes and no lights on the dash so it’s working within acceptable perimeters there is nothing wrong. (That’s a load of crap)

This part is normal for me my F150 has worked this way since day one. Engage the defrost and “stuff” happens engine comes up a little, I can feel the solenoid activate and relax as the compressor cycles and I have a different power band. Turning up the heat the compressor cycles but not as often, for those few moments between I have the performance I had before the transmission rebuild.

The only thing that changed was the transmission rebuild.

Questions: are new shift perimeters/codes entered into the ECM after a rebuild? Is there something that was changed in the rebuild that would cause me this grief like a torque converter?

Any ideas?

 

There really needs to be more diagnosis needed to figure out what is really happening, not really codes but watching the data stream from a decent scanner. This needs to be done by someone who knows what to look for and is familiar with this trans. This should help decide which way to go, transmission or a control problem.

Second gear starts from a stop in drive is kind of a rare problem for this transmission, if its not being commanded to do so from the computer it has to be some kind of valve body or solenoid problem. Valve body problems can make transmissions have all kinds of different driveability problems.

 

Thank you for your reply, I do appreciate your time.
In Canada due to the NEW emission laws we can not legally alter any factory settings.
Every two years a vehicle has to pass emission tests AND if I used a tuner the scan they do looks back on previous codes and logs them as well so the “law” knows if the vehicle has been altered.

Going back to my rebuilder is a time waister because everything is working supposedly as it should.

My little 4.6 runs great, I use synthetics and practice good mileage driving habits, Life was good with my F150 before the transmission rebuild.

I want my 5mpg that I lost back and the only way I can see of doing that is to increase the efficiency of the truck AND I don’t mean driving like some “Old Man in his Buick”

Cheers from Studio48
Law of Gravity; Any tool, nut, bolt, screw when dropped, will roll to the least accessible corner.

 

Back in the "day" when I owned and operated an RV dealership new engines and drive trains needed a break in time. Rebuilding drive units I always thought that the manufactures specs were just to darn tight so, on my own units I dismantled and re-shimmed to a slightly lessor tolerance.
The results were immediate and impressive.

Is there a possibility that with this transmission being rebuilt that I'm experiencing the "pain" of a break in period with a tight tolerance transmission that will eventually work in?

If this is the case should I have it serviced after say 5000 miles to clean the debris out of the transmission filter?

Cheers from Studio48
Law of mechanical repair: After your hands become coated with grease your nose will begin to itch and you'll have to pee