TCC lock up problem
When you first start it up and drive it, it'll lock up within a few minutes as expected. Once in a while it'll just unlock and won't go back in. Sometimes if i pull over let the truck idle for a minute or so it'll work again. Today it wouldn't. This only use to happen in the winter when it was really cold out, (we thought my aux. cooler i put on wasn't allowing the fluid to reach operating temp) but now it's occuring now in the heat. I have a tranny temp guage which is working as it should, I've hooked the tech 2 up to it before and the tranny and engine are both reaching operating temp. I've replaced the brake controler switch, TC solenoid, and 3 weeks ago I took the valve body out brought it to the tranny shop, they thought my valve was worn, even with 170,000 miles they said it showed really no wear. So they put a heavier spring on the valve to make lockup 100% instantly. This is really starting to **** me off, especially when it happenes when I'm going for a long drive, it kills my gas mileage. The only thing I could think of is the tranny temp sensor.
It acts like it's electrical related, being that it won't do it for 2 weeks then today it won't lock up at all. Also Before I took the valve body off, I checked the converters slip speed at lock up, and it was 0- -6 which is where it should be, so it almost makes me believe it's nothing in the converter. I need help guys, this is really annoying


