I have search everywhere and found no clear answer yet.

Just recently my 4r dosent want to down shift. When I'm traveling at highway speed and left of the gas it wont downshift. But as soon as I stop its ok until I get back up to 40mph or so, then it will not downshift as I let off the gas.

The FSM states:
Throttle cable faulty
Valve body faulty
Governor body faulty
Transmission faulty

I recently did 4 things to my truck.
1.Oil/filter change (not an issue)
2.Trans fluid/filter change, not a flush (fluid looked to dark and the magnets had a slight sludge on them)
3.Seafoam through brake booster and in fuel
4.Tightened slack in throttle cable(return it to starting position, after I saw that tha might be the problem)

Note: I also had an incident where the AT temp came on about one week prior to this happening. I was on the sand driving slow and it was 95* plus outside. The sand was so hot it was "screaming" as I drive over it. When the light came on I stopped and let it cool down and then headed back to the pavement and home without the light coming back on. This is what prompted me to do the fluid change.

Note 2: About 3 months ago while driving a cooler line blew and I lost all or at least a lot of my fluid. I stopped immediatly and called for a tow. The shop replaced the line and refilled the fluid. She was good as new after that.

Anyone have some advise? I know if I bring it to a tranny shop they will "rebuild" and want $$$$$$$. Other than this she runs and upshifts great. Also how do I make sure the throttle is back in the right position?

 

You need to get your tranny fluid completely FLUSHED. Just dropping than only drains about 40% of the fluid in the tranny. The vast majority of it is in the toque converter and dropping the pan doesnt drain that fluid.
On a side note, Ive never driven an automatic tranny that downshifts when you take your foot off the gas. Untill you drop to about 40 mph, they dont typically downshift untill you step on the gas.
However, the fact that you merely dropped the pan could mean you have some bad tranny fluid and that could be making your tranny do strange things.
It wont be cheap, but I would take it to a Toyota dealer and have them FLUSH the tranny fluid. That should make it work as good as new.
Cap'n

 

maybe "downshift" wasn't the right term. It just feels like its in too low of a gear when I coast from highway speed.

 

Pull the codes and see if anything is coming up as faulty.

 

no codes.

I rechecked the fluid today and it looks like its a quart low. I dont have the manual here but I think it said 5.8quarts and I put in six...WTF. There are no leaks. Is the owners manual wrong?

no tranny codes

got a 14 and 41 for the engine though...the 14 is old but the 41(THROTTLE POSITION SENSOR SIGNAL--OPEN OR SHORT IN TPS SIGNAL ) is new.

 

replace the kickdown cable, i have a 87 d50 4x4, auttomatic 4 banger, was doing the same,

replaced the kickdown cable, now its back to normal.

 

If you got a TPS code, have the TPS checked the TPS works in conjuction w the tranny ecu and tells it when to downshift and up shift. If TPS is faulty this will cause the tranny to shift eradicatly and can eventually lead to transmission failure. Just something to check out.