Hi all Re my 65 Riv - TH400 Just for my own education... I've attached a couple of pics of my kickdown solenoid/gasket and of the valve body it attaches to within transmission... If i'm correct, when the solenoid is 'activated' it creates what i believe is called 'DET pressure' which acts on the 1 2 valve up in the valve body, thus kicking down? How does the DET pressure get created?! Re the little hole on underside of the solenoid as per first pic - is this closed when solenoid is activated, and resulting vacuum or change of pressure - DET pressure - acts on the 1 2 vale? Or is a component missing and something else happens? Thanks in advance Kevin (London, England)
I'm not an expert on transmissions, but I do have books by Ron Sessions on the THM400 and the 350. Here is the page out of the 400 book that explains the detent (kick down system). This is the book, https://www.amazon.com/Modify-Hydra-Matic-Transmission-Motorbooks-Workshop/dp/0879382678 You might be able to find it cheaper. It is a great book, highly recommended.
aha! thats brilliant - 1000 thanks so the solenoid activates, and releases line pressure from the passage and the 1 2 vale does it thang... thanks again kevin