Hello all,
I have been doing some reading on this modification. Is it worth the effort? Thoughts?

It locks up by itself when you are at highway speeds, a manual switch would allow you to lock it up sooner at low speeds, but you have to be careful because the torque converter clutch isn't that strong. It would be beneficial off road so you can have better engine braking when going down a steep hill.

I understand that manual locking will prevent any torque converter slippage and improve gas mileage. Some have gotten very creative and been able to lock the transmission in any gear they need and then lock the torque converter to keep the transmission cooler. I still don't follow what the torque converter is doing and when in normal driving conditions. I wanted to see if the torque converter was working properly, so I did the 60 MPH test. At 60 MPH and around 2000 RPMs; I lightly touched the brake peddle without a change in throttle, and the RPMs changed. As soon as I left the peddle alone RPMs went back to where it was. According to what I read the torque converter is working properly. I am also curious as to how locking the torque converter while in 4WD helps you out.

Yes when the converter is locked, it prevents slippage and it will automatically lock at around 40 mph depending on throttle input. But like I said before the converter clutch, on the AW4 isn't the strongest so I don't recommend keeping it locked all the time. It will help with engine braking since when locked it is a direct connection just like a manual transmission, but you will still need to manually downshift to make it work, because of how the clutches in the transmission are set up.

Waste of time. It works just fine as designed.

I can't remember for sure because it has been awhile since I drove mine and I could be wrong, but for some reason I am thinking they stay locked in low range anyways don't they? Seems I remember mine acting almost like a manual when in low range?

Nope. TCU is clueless as to what the transfer case is doing.

Must have been my imagination then... lol For some reason I thought I remember it being pretty positive and responsive to throttle acceleration / deceleration like it was locked up.

Thanks for all the input. One last question here. Is torque converter operation related to using braking to increase engine torque to the opposite wheel when the other is breaking traction? This is an old technique that I read about when researching locking differentials.

No. Not at all.