2002 Center Diff Lock Not Engaging

[LilGoat02]

My 02 will not engage the center diff lock. I've been told it is a vacuum issue but I think my husband has eliminated that as the issue. We are feeling as though it's more electrical than anything. Correct me on a few things please as my knowledge is elementary at best since I'm just learning all this stuff:

1. On the 2002, there are three Transfer Indicator switches?

2. Of those switches, which one engages it? Would it be the first one that's near the center of the bumper and near the oil pan?

3. Can I clean the switch with electrical cleaner to see if it's just a bad connection first? I'm thinking this is a yes, but I want to be sure.

TIA

 

[WallyWest]

I don't believe vacuum lines are used for any part of the 2002 4WD system.

Do you get blinking lights on the dash when you push the lock button? Mine will rarely lock while in drive, I usually have to pop it into neutral and then it locks right up. I've also noticed that sometimes the button doesn't seem to do anything at first, and if you keep pushing it nothing happens. I think it just takes it a few seconds and if you keep pushing the button it interrupts the process. So just push it once, wait for the lock indicator to start blinking, and then possibly shift to neutral.

Maybe you did all that, but if not it's something to try.

I would say cleaning the electric contacts is a reasonable thing to do.

Also, if it hasn't been done recently change the oil in the transfer case. Mine had a leak up top when I bought it and the oil level was low. Had some issues engaging 4WD, after I fixed the leak and changed the oil it started engaging smoothly.

 

[LilGoat02]

The only time I get blinking lights is when I first engage 4WD. Once it's engaged, it sets at all green and never changes when I click the locker button. Once out of three attempts, I can hear a clicking sound when I click the locker button but again, no light change.

 

[LilGoat02]

As for the transfer case oil change, I've had it since 2007 and had no idea it needed to be changed. I asked the hubster about doing it and he said there's no way he wants a part of it because he has such a hard time putting the oil back in after it's drained. Guess I'm off to YouTube to find a video on how to do it.

 

[WallyWest]

It's not a big deal. There's two bolts, one on the bottom to drain the oil, one up top to refill it. Just remove the top one first, so if you have issues getting it off you can deal with that first instead of draining the oil and then finding out that the fill plug is stuck.

You just need gear oil, 75w-90, about 2 quarts. And a pump that screws onto the container because there's no room under there to hold it up and pour into the transfer case. All you do is replace the drain plug and then fill it up to the level of the fill plug. Just fill until some oil starts draining out of the fill plug, then let it sit for 10 minutes or so with a bucket underneath to make sure it's not overfilled.

Really not much different than changing the engine oil. The front and rear diffs also should be changed now and then, same procedure.

That said, it sounds like you have an electrical issue if you don't get blinking indicator lights when you try to lock the center diff. I would think you're on the right track looking into those switches, but I haven't had to troubleshoot that system yet.

 

[LilGoat02]

Okay cool, thanks. Since my husband refuses to help me figure out what kind of pump I need to pump the oil into the case, can you please tell me what that pump is called so I will know what to ask for at the auto parts store? I hate going to them looking for something and having no idea what the item is called lol. The other half says that oil will last forever because it's gear oil and that it should be left alone. Drives me crazy that he works on his vehicle and refuses to help guide me do most of the work myself on mine while I simply ask him to guide me. I would think it would be a man's dream to have a woman who isn't afraid to get dirty working on their own vehicle! This stuff gets expensive trying to have a shop do it LOL.

Thanks so much for your help.

 

[WallyWest]

Ha, well you can show him this.

http://www.toyota.com/t3Portal/document/omms/MSTOY01_MS0003/pdf/01omsour/2001/schedule/2001toyo.pdf

Page 41. Replace front, rear, and center diff oil, every 15k miles. I kinda doubt anyone does it that often, unless you're towing a bunch, but that's what Toyota says. So no, it's most definitely not going to "last forever".

Gear oil comes in these narrow plastic bottles with a screw top, there are hand pumps designed to fit right on the bottle. I don't know exactly what they're called, but at my Autozone they have them sitting on the shelf right next to the gear oil. It'll look something like this.

 

[LilGoat02]

You're fabulous lol! Thank you. I've changed my oil before so I'm sure there shouldn't be much problem with this. Have a great night!

 

[jgue467]

The only time I get blinking lights is when I first engage 4WD. Once it's engaged, it sets at all green and never changes when I click the locker button. Once out of three attempts, I can hear a clicking sound when I click the locker button but again, no light change.

When you attempt to engage diff locker are you just pressing the dash button quickly and releasing or holding it down for a couple three seconds until you hear a click that it too has engaged?

I used to just depress and release but have noticed if i hold it down Until it clicks (engages) and center light among 4 greens ones turns orange. Give that a try. Luck. :cowboy:

 

[Bandit Runner]

When you attempt to engage diff locker are you just pressing the dash button quickly and releasing or holding it down for a couple three seconds until you hear a click that it too has engaged?

I used to just depress and release but have noticed if i hold it down Until it clicks (engages) and center light among 4 greens ones turns orange. Give that a try. Luck. :cowboy:

Good advice.

OP: Try holding the button in for a second or two. I've noticed this same thing.

 

[LilGoat02]

When you attempt to engage diff locker are you just pressing the dash button quickly and releasing or holding it down for a couple three seconds until you hear a click that it too has engaged?

I used to just depress and release but have noticed if i hold it down Until it clicks (engages) and center light among 4 greens ones turns orange. Give that a try. Luck. :cowboy:

I was able to make it work. Thank you!!