Transmission downshifts when letting up on throttle

[Generallee]

Ok, 2001 dodge cummins 4x4 333000 miles. Original transmission. Barely any flakes at transmission oil changes. 

Driving the truck at 35 mph and 3rd gear. Letting up slightly on throttle it downshifts to second. Takes lots of throttle to kick back into 3rd. Also does the same thing at higher speeds downshifting from od to 3 when going down a hill or letting up on throttle.  

     I assumed it was the gov solenoid and transducer. Changed that with the kit from cassadia transmission on eBay. It didn't change anything. Adjusted tv cable. Didn't change the problem maybe moved the speed slightly as to when it happens. Took it to a shop I trust for them to run it on scan tool.  The only thing he noticed was the voltage to the gov pressure sensor never changed voltage.  

Part 2 of the question is when letting off the throttle rpms go to idle rapidly.  Is this normal? 

Any help or testing ideas would be wonderful. Automatic transmissions baffle me. Give me a engine, and I'm fine but I get easily confused with these and I'm not even blonde. Thank you in advance. 

[Me78569]

Are you %100 sure that it is downshifting?  That speed is right around where the TC locks and unlocks.  Same thing will happen in OD, If you let up on the throttle the TV cable pulls less and the trans might unlock the converter if you are right around 45 mph.

 

 

 

 

Is this a new issue?  

[Generallee]

The truck is a friend's.  He said it's done it a few times at higher speeds. But never lower speeds. And it's all the time now. I'm assuming it's downshifting because putting it manually into 2 when it does this doesn't change anything. But I could be wrong. (it happens to me a lot.) 

 

When it "downshifts"  to get it to "upshift"  takes about 2300 rpm even at 35 mph.  I'm guessing at the rpm. I don't remember exactly. It's high though more than normal. 

Edited August 19, 2016 by Generallee

[Me78569]

I would start by making sure the tv cable is adjusted correctly.  

[Generallee]

It seems to be. Moves right away. Smoothly. Throttle wide open have maybe an 1/8 inch movement left. 

[Generallee]

I'm changing my question. I think you are correct that it's the tc coming out of lockup. I have checked for ac voltage. I have pulled the fuse for the alternator.  

Is it normal in these trucks to go directly to idle when letting off the throttle? 

[pepsi71ocean]

This is as normal as my truck does exactly the same. 

[Generallee]

Ok I got a test Guage. Governor pressure seem correct. 

Connected to front servo. 3-4 shift around 60 psi.  Slight let off throttle. Pressure drops to 20. Get back on throttle. Eventually pressure comes back up and shifts again. Should that servo pressure drop just from backing off the throttle slightly? 

[Generallee]

Also when slowing down pressure is at 20 then it spikes to 55 there is a clunk, and then to zero.