...there is a bunch of info here.
4L60E Reference Material
http://forum.efilive.com/attachment.php?attachmentid=15615&d=1375249294 15615forum.efilive.com
This link (below) shows two hydraulic circuit diagrams of the TCC (locked and unlocked) with detail that I didn't see in @Supercharged111's link:
The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - >>>> 700r4 lockup question <<<<
Community resources for all classic chevy and gmc pickup trucks
67-72chevytrucks.com
All I've managed to glean from the two figures is that:
- when unlocked, the valve routes all of the fluid to the TCC; from the TCC the fluid then returns to the valve where it is then routed to the cooler circuit (and then on to the "lube" circuit that lubricates the front of the transmission), and
- when locked, the valve splits the fluid; part of the fluid from the valve (a) is routed to the TCC, and from the TCC the fluid returns and is exhausted to the pan and (b) the remaining part the fluid from the valve goes to the cooler circiut.
The volume of fluid passing through these components in the unlocked and locked states isn't clear to me. I haven't determined what device / orifice is controlling the fluid volume in the locked or unlocked case.
Volume of fluid is key, with higher volume offering improved (a) heat transfer to the cooler and (b) oil flow to the "lube" circuit.
My observations are NOT definitive. Maybe someone can springboard from my comments.