Center Diff Lock came on out of nowhere -is it functioning properly?

[Superhero]

2007 V8 4Runner, 175k miles.

I was stuck behind a train the other day so I turned off my vehicle while I was waiting for the train to pass. It was taking forever so I decided to go another route. I started my 4Runner and went to pull out of the line of cars with a full steering lock left turn and I noticed that my center diff lock was on. I started the turn on damp pavement and ended it on gravel with diff lock on the whole time. I pushed the button right as I noticed it (halfway through the turn) and it disengaged shortly after. Should I be worried about powertrain damage because of this?

Pavement was wet/damp. No tire barks, no heavy steering, couldn't tell the CDL was engaged until I saw the light. Tested afterwards while driving straight line on pavement and it came on and off no problem. On PT 4wd vehicles you can definitely tell when you engage the transfer case because steering gets really heavy etc. but I don't use my CDL often and am wondering if I would notice the same effects with the locked torsen.

Can the CDL be disengaged even with the light on the dash indicating that it is engaged? I drove through some really deep water (some Denver roads tend to flood out a foot or two deep), wondering if this may have somehow caused the CDL to engage, or perhaps report that it was engaged when it wasn't? I never hit the button and it was disengaged when I shut down the vehicle as far as I know. If I had been driving around with the CDL engaged on damp/wet pavement for a dozen miles, should I be concerned about drivetrain damage? Is there anything I can do to check?

Is there a way to test my CDL to make sure it is engaging/disengaging properly without risking breaking stuff?

Thanks!

 

[originalg00kster]

If you were just driving down the highway in a straight line you should be fine. Why don't you try engaging it now? Just make sure you're in neutral when you engage CDL.

 

[RonJR]

It's unlikely you damaged anything if you didn't feel the tires scrubbing and skipping when you made your sharp turn. It's likely the CDL was never actually engaged, and instead that the sensor got fooled by the excess moisture.

Although it's not recommended to engage part-time 4wd or the CDL on dry pavement, especially if you are turning sharply, the drive train is pretty tough and normally the tires will slip before anything breaks. Anyone who has wheeled in Moab has experienced turning on dry slick-rock (which is anything but slick) while in 4Lo and feeling the tires hop. It's seldom that anyone talks about breakage in those situations.

If you did break anything it would likely be a front CV shaft, and you'd know right away if that happened.

 

[Superhero]

Thanks for the responses!

I have never put my 4Runner in neutral before engaging the CDL. What is the reason for this? It always seemed to work just fine on the fly. Hopefully I wasn't breaking or excessively wearing stuff out by not going into neutral.

The light on the dash comes on and off when I push the CDL button, but since I can't tell by the way it drives whether it is on or off (in my Jeep if you lock the transfer case you know for sure it's in 4wd by how it handles) I'm wondering if it is actually engaging/disengaging.

 

[RonJR]

Normally you don't have to be in neutral to engage the CDL. Sometimes it takes a bit of forward (or reverse) motion before it locks. The light should blink until it actually engages, then go steady when it's locked in.

Just go out to a parking lot, engage the CDL, wait for a steady light, and then make a slow, fairly sharp turn. Don't apply much power. It should feel like you just stepped on the brakes. If the vehicle turns without resistance, the CDL is not actually engaged.

If it does resist turning, your test is complete. Don't push it further, instead stop, back up to relieve the drive train windup, and disengage the CDL.

 

[Superhero]

That's exactly my experience.

I'll try the slow parking lot test and see how it goes. I know what my Jeep feels like on pavement locked into 4wd but don't know that I've ever experienced that with my 4Runner. I just chalked it up to being a different system. Of course, I don't think I've ever intentionally locked up my 4Runner on anything dry before so may never have had an opportunity to feel the drivetrain bind.

Normally you don't have to be in neutral to engage the CDL. Sometimes it takes a bit of forward (or reverse) motion before it locks. The light should blink until it actually engages, then go steady when it's locked in.