You have a first design valve body with a 2nd design 1-2 shift valve train installed onto the transmission per your pics above...Tells me it's a 1987 valve body...Since you have a 1988, you should have a second design valve body but it's possible that@NickTransmissions , I know you told me to leave it alone, but Im trying to prove that I didn't get back what I took him or at least got a different valve body.
Can you take a look at these pics and let me know what you think? I dropped the pan and found what looks to be the hydraulic valve body not the electronic valve body... I think this confirms my suspicions... Same numbers as in your video of the early 87 valve body and the open port for the hydraulic TCC.
Also in your valve body video you called the switch beside the 4th gear pressure switch a 3/4 pulse valve(?). My trans guy called it a temp switch. You can see the jumper he made in one of the pics to remove the "temp switch". Is he calling the same switch by a different name?
@Erik the Awful , I feel kind of hacked right now...
a) the shop swapped valve bodies because the builder felt there was issues with the original valve body (you can install a 1st design valve body onto an aux vb case but you cannot install a 2nd design valve body onto a non-aux case)
b) That is the original valve body, as installed at the factory simply due to those VBs still sitting on the shelf...
You can tell it's a first design valve body by the existing of the TCC control bore being cast into the valve body (2nd design valve bodies don't have it - the housing has nothing there on a later VB).
The temp sensor can trigger TCC apply if it hits a certain threshold since less heat is generated when the TCC is enabled. That said, I would have put a Rostra replacement harness vs reuse the original given it's age. Here's an example from a 1987 unit I just got done building; it has the same exact valve body that you have and replacement Rostra harness installed.
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