Mini maxx and the torque converter

[D-Low]

I've tried to find the answer but haven't had any luck and asked a few people but only got confusing explanations. So here is my question, what exactly does it do when the torque converter locks and is it better to have it lock only in 4th gear or both 4th & 5th? It seems almost like its shifting into another gear when it goes from 4 to 4tc locked. I'm not worried about anything being broke or damaged here, I'm just looking to get an understanding of what is doing what and were it will work to my advantage.

[bigblockbill]

There are some clutches in the converter that unlocked are allowed to slip whereas locked the converter is 1:1. If its unlocked while driving it’s like having your foot part way down on the clutch pedal and letting it slip a little bit. While slipping it makes for softer gear changes and allows smoother power delivery, helps the motor stay up in the RPM band, and all of that generates large amounts of heat which is bad for the tranny. Now when you’re in 4th and unlocked and pulling a hill you are essentially losing power into the converter that could be going into the tires. I would say you want that sucker to lock and stay locked as soon as possible under most circumstances.

[D-Low]

Thanks for the reply Bill, that helps me understand what's happening better than the other explanations I've gotten.