2007 Eaton Gen 3 Automatic Transmission

That input speed not matching output speed could be telling.
When you drop it in gear the input speed should drop to zero with in a few seconds.
When you put it in gear and the input shows an rpm signal but the output sensor shows zero rpm ( because your foot is on the brake and the truck isn’t moving) the computer sets a code because it knows there is loss of connection (slip) between the input and output.
On the smaller units I work on this Usually triggers the inhibit strategy in the computer and you then get basically neutral and the engine won’t rev up till you clear the code.

 

The ones that have no pedal made a clunk as you increase the rpms close to 900. It is normal so if you let your rpms drop the clutch will clunk as it unlocks

 

I think the clutch is dragging. May be intermittent with a dislodged dampening spring. Makes sense that it would drag more when warm as the parts expand. Also when warm the internal trans is warmer and fluid viscosity is less, everything rotates easier.

 

I would be curious to know if when you were able to get an input speed of 140-150 and you drop the trans in gear
does the input speed immediately drop to zero?
If it doesn’t immediately drop to zero than the input clutch’s in the input drum are slipping and are most likely toasted.
Not uncommon for fried automatic clutch’s to half ### drive when cold but slip like hell when warmed up.

 

You pretty much have a diagnosis of the problem with that information.
Normally operation is when you drop it in gear the input shaft speed drops to zero.
This occurs because Internal of the transmission on the opposite end of the input shaft there is a hydraulic clutch pack that locks up when you drop it in gear.
Once that clutch pack is applied you have mechanical power flow thru the transmission down the drive shaft thru the axel to the wheels that are being held by the brakes.
So if the truck is not moving the input speed should be zero.
I believe the clutch up in front of the trans is fine because if it wasn’t it couldn’t spin the input shaft and you would also have zero input rpm but the truck would not move.
The problem unfortunately is an internal forward clutch pack problem because it is no applying properly.
This is caused by either the forward drum clutch’s being burned up or a sealing ring issue that causes low apply pressure.
Your ability to apply the clutch’s when cold but not hot is usually caused by the thicker oil when cold causing increased oil pressure in the unit which causes higher applying pressure on the clutchs.
I hope I explained it well enough to make sense to you?
When I get out to the shop tomorrow I will see if I can dig up an input drum and shaft and post a picture of it to kind of illustrate what I am saying.