Created on: 2020-05-19
Watch this video to learn how to install a new neutral safety switch in your 1988-02 GMC Sierra.
13mm Socket
Socket Extensions
Flat Blade Screwdriver
Rust Penetrant
15mm Socket
Socket Driver
Pry Bar
Jack Stands
Wheel Chocks
Ratchet
Floor Jack
Trim Tool Set
Now that we've made our way underneath the vehicle, we have a clear view of the neutral safety switch. It's right along the driver's side of the transmission and it has this cable that runs to it. To get started, we're gonna come right above the driveshaft. There's a nut that holds this arm on. We're gonna remove that nut using a 15-millimeter. There it is. See if you can wiggle this off. If you can't wiggle it, just go ahead and grab a pry bar. Okay. Swing that down and out of the way.
The next thing we're gonna do is use a forky tool that looks like this. Come right up along here. There's a little securing point for the wiring harness. Just go ahead and remove that from there. Now we're gonna remove the wiring harness from the actual neutral safety switch itself. You can do that by grabbing the little tabs and then drawing the wiring harness off of it. Of course, take a peek at your connectors. Make sure they're in great condition. If you see any funny colors, you're gonna need to service it. Take this one off, pop that off, take a peek. Looks great. So now all that's left, of course, is to clean down this area, and then we're gonna go ahead and take out the mounting bolts. There's one right here and one located near the electrical connectors.
Next it's time to remove the 13-millimeter mounting bolts, one right here, one over here next to the electrical connectors. Gonna loosen this one as well. Let's grab onto that. You can wiggle it around a little bit. The next thing we need to do is be able to pull it off of this shaft right here that comes out of the transmission. So carefully go in between your transmission pan here and the plastic housing and just try to pry it away. If you wanna use a little bit of penetrant along the shaft, it's probably a great idea. Okay. It's sliding right off. This is great. Get that out of the way. There it is. All right.
So now at this point what you can do is you can take this, slide it back up over that shaft. It should wanna go on there. Now you're gonna use your forky tool, come right in between here and here and we're gonna separate that. Now you can take this and you can go back two clicks. Ready? One, two. That's neutral right there. All right. If you need to double-check it, just go ahead and go back all the way to the front. Park. One's reverse, two's neutral. We'll get this back off of here now. Now we're gonna grab our new neutral safety switch. If you look at it, it's got this on it right here. That's already got it lined up so it knows when it's in neutral. So at this point we're just gonna slide it right over the shaft and the bolt holes should line up exactly where they need to be.
Let's see if I can get this on there. Okay. That slid right on. This is looking good. Right like that. Perfect. We can get our little tool out of there. That came in handy. We've got our two mounting bolts. Go ahead and start them bolt in before you tighten either of them down. Okay. Just make sure they're snug. Perfect. Okay. Just make sure they're snug. Perfect. Now it's time to get our arm back on there. We've got our nut. If you wanna use a little bit of threadlocker, we'll call it your prerogative, but you shouldn't have to.
Okay. Now you're gonna wanna use an 11-millimeter wrench so you can hold this shaft still so it doesn't spin. Hopefully. And now we're gonna tighten that up using our 15-millimeter. Okay. I'm just gonna hold it with a wrench, snug it up. Perfect. Push this all the way back to the front. That's the park position. It should line up perfectly with the cable, and it does. Go ahead and squeeze that together. It clicks right in. Make sure it does not fall out. And if your boot came off, make sure you slide that up. This one looks like it could use a wire tie. It's time to put in these electrical connectors. The bigger one goes on top. Make sure it goes all the way in and clicks. Give it a nice tug. That feels great. Do the other one.
Make sure it locks in. Tug, feels good. We've got our securing area here, anchor point. Slide that in. Beautiful. Double-check everything. This looks good. Looks good. Everything looks great under here. If you by chance have any fluid-like what we do, I would just clean it down. And then let's get up top and check to make sure that our indicator is lined up. Let's run through the gears. We've got reverse, neutral, drive. Oh, this is perfect. Awesome. If by chance your indicator is off for some reason, you would just loosen your mounting bolts again just a teeny bit. Rock this a teeny bit in one direction or the other until it lines up. Then go ahead and snug it and recheck it.