If you let your truck overheat, even a little, over an extended period of time it will have negative side effects on the tranny (assuming you have the stock in-rad tranny cooler). Get that fixed before it causes more problems.
Take the truck to a tranny shop (or any shop with a badass scanner), have them hook it up to a scanner and reproduce the problem to determine if it is in fact the TC clutch. You will not be able to do this will any run-of-the-mill scanner, and it will not necessarily set a code.
The goal is to see when the PCM commands lock-up, and compare that data to when the problem occurs. If PCM says lock, and that's when the truck shakes, you will need to replace the TCC.
EDIT: as far as the coolant leak, look at the little peice of hose that comes off of the intake, runs under the accessory bracket, and goes into the top of the water pump. It's kind of hard to find if you don't know what you're looking for.
Perhaps a pic of where the leak resides could help us locate its source.
Last edited by Mad_Scientist; 05-08-2011 at 02:49 AM.