Torque Converter Random Unlocking,47RE
 

So it started saturday on a cold 5 degree morning taking off from my parking spot, and my truck gets to about 1600rpm in 1st gear (where it normally shifts) than it all of a sudden the Converter totally unlocks and smacks back into gear, almost felt like it was spinning on the ice, than getting back onto traction. This happaned twice right after taking off from stop lights, and does it quite periodically. So I already know the trans and especially the Converter is weak, but before i let it get worse and bite the bullet for a built trans, could it be a sensor of some sort thats causing it to let loose? I had a speed sensor go bad that was causing it to shift, lock, and unlock the converter, basically at random, but replaced it and all was fine till now.

Check Ur ground wires on your batterys n on your pcm and maybe spray some cleaner on that speed sensor. Hope this helps

Well now its starting to do it a lot more, like coming off the pedal than getting back into acceleration, the TC doesnt want to lock right away. Ill pull some sensors and do some wire checking,

Thanks :tu:

Check and Clean all the grounds on the truck and you may need to get a APPS noise isolater to take care of the noise interference at the pcm

I'm sure you already checked, but is the trany full of fluid? How does the fluid look? When was the last time trany fluid and filter was changed?

What do you mean by apps noise isolator? And ya the fluid isn't perfect but its full. It's definetly the TC just by the way it acts.

BD apps noise isolator. I have one on mine. It will clear up the tc going in and out of lockup at cruising speeds. By what you are describing, I don't think it will help you any but it's cheap and worth a shot.

Alright i looked into the Noise isolator and that looks like a good start. But if i need to Start looking at an entire transmission in general i was thinking about suncoast? anyone have thoughts about them or other shops?

T/C shouldn't lock up until 3rd and O/D, unless you have a T/C lock up switch. Are you sure it is the T/C locking up and unlocking, or is it jumping between gears?

Well if the TC isn't supposed to lock than what is it causing my motor to basically free spin in first and 2nd. it does it at 1500 RPM in first. Ill be driving and it will almost always let loose around 1500 and spin up to 2100 or so than slam back into gear. Than in 2nd, if i am taking a turn and getting back on the pedal it will free spin worse and sometimes doesnt re engage till it shifts the transmission down to first. It doesnt feel like its jumping between gears. once it gets up to thirsd its solid like it always has been.