Hello, I am having an issue with my 2003 46re 4x4. One day suddenly it would not shift into overdrive on the way to work. Would not shift the whole way there or back.
Over the course of the next couple of days it would finally shift into OD after about 20 minutes of driving, nice and firm just like it should. I gave it gas and downshifted to verify that it would upshift again. At highway speeds it would shift right back. Coming from a stop, when it was time to shift, it would hesitate once again. Sometimes turned OD off and back on would get it to shift.

The problem has been intermittently worse and better for the past week, sometimes it would shift after 5 minutes of driving, sometimes not until after 45 minutes. Turning OD off and back on no long does the trick but I found that after it warms up, if I downshift into passing gear after about 3 or 4 times it would finally shift.

The fact that when it does shift that it shifts nice and firm like it should, leads me to believe that it is less likely mechanical and more likely electronic or pressure related, but am not going to rule anything out at this point.

So far changed the filter and my next step is to change the governor pressure sensor and then OD solenoid. I inspect the 3-4 accumulator spring and it looks good. Is there anything else that I should look for?

 

I think the O/D solenoid would be the likeliest first step. Might want to plug in a code reader, and see if the PCM is thinking about whining about it.

 

There have been 3 occurrences that the CEL has come on throwing a P0783 code, 3-4 shift. There is no rhyme or reason to the PCM finally throwing the code.

 

Yep, that's a solenoid failure. There are a few possible causes, ranging from dirty fluid, to pressure leaks. When you drop the pan, see if there are bits of the the O/D snap ring laying in the bottom of it.

 

No pieces of snap ring, just a bit of friction material, presumably from break-in. All clutches and bands were just replaced about 3,000 miles ago and no other issues.

 

Was the solenoid changed when the trans was rebuilt? Done by a shop? If so, there should be some flavor of warranty on it.

 

No electronics were changed during rebuild.

 

Ah, then, it's time. Do them ALL. (about 200 bucks, plus fluid and filter.) Get the heavy duty borg warner governor solenoid set.

 

Pressure sensor and Solenoid were replaced with BW about 5,000 before rebuild and will clean, I have a brand new solenoid pack, just wanted to confirm that it was defective before I changed it, along with any other possible suspects.

 

Time to get dirty then.