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4T80E external neutral safety switch (I think)

Hi all,

I’ve been trying to find some more information on the part circled in the picture below. This 4T80E is from an unknown vehicle (the metal tag that I think is supposed to be bolted along with the valve cover is not there). So not sure if I’m out of luck or if there’s any other places that will have the transmissions identifying codes stamped on

I know that some components were internalized after a certain year including the neutral safety switch, and knowing that stamp info would help me know my final gear ratio!

When this transmission showed up, it came with no sensors or anything. We went to the junkyard to see what parts we might need. We found multiple cars with 4T80s. Here’s where the question comes in, some had the part circled in the picture below, some didn’t. It goes on the shift selector stalk, and has two wire connectors to it and what looks like a vacuum line?

One place I looked up said this was a neutral safety switch? But this seems entirely electronic? Some of the cars in the junkyard had this, others didn’t (and given the shifter cables were still on, we assumed they never had one).

If we are using a mechanical neutral safety switch in our gear selector, do we need this circled component? And if we do, any input into how it works would be appreciated. We do have the shop manual, but it hasn’t been great on details around this component us in on this part. If we don’t need it, it will make routing the exhaust much easier to do! I just assume we can tune out any warnings/interrupts it would be throwing to the ECU (likely going with Holley Terminator or MegaSquirt).

EDIT: took the img tags off the link. The box was appearing but showing broken in thread, however when I right-clicked and examine object, it was previewing right in the window. So guessing the forum doesn’t like PNG? If you click on the “broken” picture below it pops up correctly.


That does look like a neutral safety switch. They may vary in appearance in different years or applications. By vacuum line do you mean the area on the lower right? If so, that looks like a stub of wire harness protector. There are no vacuum lines involved that I’m aware of.
There is an ear inside of the neutral switch and the manual shaft out of the transmission is what rotates it.

I do not know how you are setting your gear selector up but I would want a safety net built in. I can’t think of any issues that would be caused by removing it other than some diagnostic codes which may be set. With the exhaust running that close to the neutral switch I don’t see it having a lengthy lifespan anyway.

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Thank you so much! And you could be right on the thing I was misidentifying as a vacuum line. I took that picture about a month ago and had been scouring the internet trying to educate myself before I gave up and started posting this question in a few places. You were the first to know for sure! :slight_smile:

The gear selector we’re setting up with this has the old school “push button” selector that exists in the shifter itself as the neutral safety.

You are exactly right about the exhaust, we stopped with mock-up until we had an answer on this, so we knew how we needed to proceed. I’m glad to hear we can take that off and just tune out any codes the ECU/Trans controller throws.

I’ve read (so who knows) that the stock ECU would put the transmission into 2nd gear and leave it there if it saw an issue with the neutral safety switch. But since we’re not using the stock ECU, I don’t foresee that being a problem. I hope!