4Lo won't engage - Beeping coming from actuator itself??

[TakeitApart]

There really are way too many things that can cause a 4WD concern on a 4th gen and up 4runner to get an accurate diagnosis on the internet. Sure, we can take very educated guesses and recommend parts, but there are limit switches, the control switch, ADD actuator and limit switches there, t-case motors, 4WD ecu, etc.

One thing I can tell you for certain. Don't ever move any actuators by hand, or remove electrical parts of the 4WD system without disconnecting the battery. If anything gets out of time, you may never get it back in synchronization.

 

[crazyborder]

Finally fixed it!!

After doing battle with my 4lo on and off for the last 3 year, I FINALLY fixed it. Problem is I'm not sure which step or steps can take credit. That said, I thought I'd share what I did in hopes that it helps someone with the same problem. My suspicion though is that the battery reset is what did the trick. Anyhow, here's what I did:

I loosened the three bolts holding the actuator to the case (maybe 4 or 5 cranks of the wrench- enough to get it to come out an eighth inch or so). Once it was lose I sprayed a small amount of WD40 in between the case and actuator then tightened the 3 bolts up.

After letting it sit for a few minutes I jumped back in the truck and continued flipping between 4hi and 4lo and would keep it in 4lo every time I didn't hear the beeping from under the truck and would leave it in that position for 10 seconds or so. After I did that a few times things got bad... I thought I'd broke it and broke it good. 4hi would not disengage and the 4lo light (and beeping) wouldn't stop no matter what position the switch was in.

At this point, I had to go back to 'cure-all' we used to use at Circuit City when we triggered check engine lights by accident when installing remote starters and that was to disconnect the negative battery terminal for 5 minutes.

After 5 minutes, I reconnected the battery and started the truck. The faithful cure-all had done it again! Phew! All the warning lights had gone back to normal and things were back as they were supposed to be.

I tried 4hi and it worked so I was feeling better. I moved it over to 4lo and wouldn't you know it... there was the 'chunk' noise of the low gear kicking which I hadn't heard in 3 long years!! What a magical noise that was. I cycled through everything a few more times then took it out for a drive. It all worked exactly as it was supposed to!!! To say I was thrilled would be an understatement.

So long story short, I'm really not sure which part of that song and dance made the difference but either way, if you hear that beeping coming from the actuator itself like I did, give this a shot! The only thing I'd probably skip on the first try is the WD40 since that may not have been a good thing to do.

I hope this helps someone avoid that really expensive repair. :ybrick:

 

[JB.]

Sweet!

Probably feels like you have a new truck.

Enjoy

 

[crazyborder]

It really does!!

 

[eviele]

Glad you got it to work OP.
I bought a 2006 SE about eight weeks ago. It had a one month warranty and shame on me, I didn't test 4LO before purchasing the vehicle.
Brought it home and days before my warranty expired I tried 4LO and no go. It beeped under the 4runner just like you mention.

I gave myself the weekend to exercise the system and see if I could get it to work. Eventually, by Sunday afternoon it was working.

My secret was to run the truck for awhile to warm things up.
I just left the truck idling and would exercise the system, switching from 4LO to 4HI and back again. Then I'd go putter a bit and come back and try again.

Eventually it made a noise like grit grinding in between metal. I was afraid I ruined the damn thing, but I kept exercising it and the grinding noise faded away after the third or fourth engagement of 4LO. Now it works pretty well. It's slow, not instantaneous, but it does work and it doesn't make any noises like before.

My goal was to warm up whatever grease might be affecting the actuator and hopefully thin it out enough to get things moving. My guess is the noise it made was indeed dust and dirt and whatever else in with the lubrication.
In short, I got lucky and glad it worked. Just wanted to add my approach to those desperate for a fix. Good luck all.

 

[nevada]

After doing battle with my 4lo on and off for the last 3 year, I FINALLY fixed it. Problem is I'm not sure which step or steps can take credit. That said, I thought I'd share what I did in hopes that it helps someone with the same problem. My suspicion though is that the battery reset is what did the trick. Anyhow, here's what I did:

I loosened the three bolts holding the actuator to the case (maybe 4 or 5 cranks of the wrench- enough to get it to come out an eighth inch or so). Once it was lose I sprayed a small amount of WD40 in between the case and actuator then tightened the 3 bolts up.

After letting it sit for a few minutes I jumped back in the truck and continued flipping between 4hi and 4lo and would keep it in 4lo every time I didn't hear the beeping from under the truck and would leave it in that position for 10 seconds or so. After I did that a few times things got bad... I thought I'd broke it and broke it good. 4hi would not disengage and the 4lo light (and beeping) wouldn't stop no matter what position the switch was in.

At this point, I had to go back to 'cure-all' we used to use at Circuit City when we triggered check engine lights by accident when installing remote starters and that was to disconnect the negative battery terminal for 5 minutes.

After 5 minutes, I reconnected the battery and started the truck. The faithful cure-all had done it again! Phew! All the warning lights had gone back to normal and things were back as they were supposed to be.

I tried 4hi and it worked so I was feeling better. I moved it over to 4lo and wouldn't you know it... there was the 'chunk' noise of the low gear kicking which I hadn't heard in 3 long years!! What a magical noise that was. I cycled through everything a few more times then took it out for a drive. It all worked exactly as it was supposed to!!! To say I was thrilled would be an understatement.

So long story short, I'm really not sure which part of that song and dance made the difference but either way, if you hear that beeping coming from the actuator itself like I did, give this a shot! The only thing I'd probably skip on the first try is the WD40 since that may not have been a good thing to do.

I hope this helps someone avoid that really expensive repair. :ybrick:

sweet. glad you got it.


honestly, I expect that is that is what got it unstuck. good idea to get some lube/penetrating oil in there on those parts.

if I were you, I would make sure and cycle the system at least once a month to keep it working correctly.

 

[crazyborder]

Most definitely! It feels like I have a new toy to play with now so it'll definitely get cycled through regularly from now on.

 

[CookieRoe]

scared.........................

Most definitely! It feels like I have a new toy to play with now so it'll definitely get cycled through regularly from now on.

Since I bought mine (March 2010), I never touched 4Lo. This thread gives me some hope. I was already resigned to my probable reality that my 4lo actuator was(is) frozen.

I'm just scared that it might not "go back into 4Hi while trying to engage in 4Lo". I've read where this happened to some. Supposedly you are toast if it won't engage back. Not ready for a ~$2500 repair(replace).

Urrrrrrrrrrghhhhhhhhhhhhh what to do.................

I'll have a mallet/toolbox/WD40 on hand when I do decide to.

 

[J053619]

Since I bought mine (March 2010), I never touched 4Lo. This thread gives me some hope. I was already resigned to my probable reality that my 4lo actuator was(is) frozen.

I'm just scared that it might not "go back into 4Hi while trying to engage in 4Lo". I've read where this happened to some. Supposedly you are toast if it won't engage back. Not ready for a ~$2500 repair(replace).

Urrrrrrrrrrghhhhhhhhhhhhh what to do.................

I'll have a mallet/toolbox/WD40 on hand when I do decide to.

Not sure if this gives you any hope, but I have an 06 and my fams been the only owners. It was NEVER turned into 4Lo since the day it was bought in end of 05 or 06. I ran across these forums when i took ownership in 2012 and the 4lo was the first thing i kept trying to work. For about a month i kept whacking it and trying to get it to turn on, but only got the beeping. I gave up and considered it a lost cause.

Until about a few weeks ago i went wheeling and after an hour in i decided, what the hell maybe it'll engage. As soon as i turned on 4lo, it turned on instantly. I'm guessing the rocking around and whacking the actuator as some have tried here helps free the components inside. Now I turn on the 4lo almost every other day to make sure it doesn't happen again.

Maybe you just need to take her off road to remind her what the 4lo is for :bounce:

 

[Minnesota Yota]

Best possible outcome!

So, a few months back i realized while trying to pull a friend out of a ditch that my 4lo was not engaging. Hadn't given much thought to it until tonight because we just got 8 inches of snow and I was out obeying all the laws and not taking advantage of the fact that the plows don't go out until 10pm. I was out on a country road and thought it would be a good time to see if 4lo would kick in so I could show the wife and kids what the difference is and teach them a quick lesson in gearing, no-go:crybaby: came home, read this and went out in the garage and with the key in the on position,engine off,trans in Neutral, radio and fan off, cycled 4hi,center diff lock and 4lo. Didn't engage 4lo but, I could hear all the individual actuators doing their thing. 4hi to 4lo about 3 times and BOOM! everything is right with the world again, in my slippers no less!:whoo: Of all the things I have ever fixed that has to be in the top 5 for easy and/or lucky! So I guess the point is that you should listen and see if you can hear the components before you jump to a conclusion or worry about spending a mortgage payment on 4lo. And for the record if you are wondering, the 4lo light will go solid and quit beeping when it engages.

 

[Kmvreter]

... Now I turn on the 4lo almost every other day ...

Glad it worked out for you.

Just saying: http://www.toyota-4runner.org/4th-gen-t4rs/163282-4x4-psa-use-lose-monthly-reminder.html

 

[scw1991]

Tried this as well but no luck. How much did you loosen it? Im scared to pop it out too much and mess it up even more.

I loosened the three bolts just enough to wiggle the actuator side to side (not in/out).

There is a thread I created showing the front diff actuator motor which is identical (if not mistaken) to the 2 motors found in the transfer case actuator. It was completely seized up, plus the electrical connection to motor had come unsoldered. Definitely not what I consider a robust design, but it does state in the Toyota manual to properly cycle the 4WD monthly.

http://www.toyota-4runner.org/4th-gen-t4rs/162097-front-differential-actuator-disassembly-pics.html

 

[Floki251]

Was trying to get my 2007 V6 to go into 4lo tonight and at first I heard the beeping everyone was talking about. After many attempts the beeping stopped and now I can not take it out of 4hi.
The 4wd light is solid and the 4lo blinks no matter what position the selector is in. I tried unplugging the battery for 15 minutes, no change. Jacked all 4 tires up off the ground and attempted to change out of 4hi, no luck. Any one have any ideas here?

 

[Martinjmpr]

Was trying to get my 2007 V6 to go into 4lo tonight and at first I heard the beeping everyone was talking about. After many attempts the beeping stopped and now I can not take it out of 4hi.
The 4wd light is solid and the 4lo blinks no matter what position the selector is in. I tried unplugging the battery for 15 minutes, no change. Jacked all 4 tires up off the ground and attempted to change out of 4hi, no luck. Any one have any ideas here?

Did you put it in neutral before you put it into 4 lo? Might try that. You have to be in neutral with the transmission when going from 4hi to 4lo and vice versa.

 

[Floki251]

Did you put it in neutral before you put it into 4 lo? Might try that. You have to be in neutral with the transmission when going from 4hi to 4lo and vice versa.

Yep I was in neutral while trying, foot on the brake too. Started another thread, don't want to clutter this one with my problem. Will post my solution here too if it is related.

 

[BriRunner]

Keep on switching...I got lucky!

I appreciate the advice of this awesome forum and I wanted to share my fortunate experience with a recently purchased 06 V8 sport (194000km=120,000miles), of course when looking at the vehicle i tried and tested everything but the low range! A day later after the purchase from the original owner, I tried engaging low range, and nothing! Flashing 4lo light. I was mad at my myself. I asked the seller if it had ever worked and he said he's never turned the dial since new! So after reading here I crawled underneath and tapped the actuator box and transfer case with the rubber handle end of a hammer while my GF turned the 4lo dial on and off for about 10 mins. I was about to give up, shut off the engine. But then started it up again, hit the 4lo and BANG! After a light buzzing grind the light stayed on and its in! After jumping for joy and drove to a gravel side road and kept working it back and forth from 4hi to 4lo. Now it goes in with no issues! So to all the other 4th gen owners having the same issue, just keep trying it over and over. You may get lucky! I don't know if the hammer tapping really had any affect but it worked for me!

 

[BriRunner]

Yep I was in neutral while trying, foot on the brake too. Started another thread, don't want to clutter this one with my problem. Will post my solution here too if it is related.

I feel your pain! Try what I did and crawl underneath and try tapping the actuator box area lightly with a rubber hammer while somebody turns the 4lo switch back and forth from 4hi and 4lo. Sometimes that will loosen up any seized parts.

 

[07Profiteer]

I had the same issue when I bought my 4Runner in January. The 4lo would not engage because the actuator was frozen. Once it got warm and after driving the vehicle a while I would keep trying to get it to break free by switching to 4lo. After a few months of occasionally trying this I am happy to say that last week on a hot day after driving for a while it finally went into 4lo! :wink2: I figured that I have never needed 4lo as I do not off road so i was not going to physically get under there and work on it nor was I wgoing to pay $2k to have it fixed. So I just kept trying it and now it works! I just need to keep using it every few days for a while to make sure it keeps working.

 

[b.hog]

I had the same issue when I bought my 4Runner in January. The 4lo would not engage because the actuator was frozen. Once it got warm and after driving the vehicle a while I would keep trying to get it to break free by switching to 4lo. After a few months of occasionally trying this I am happy to say that last week on a hot day after driving for a while it finally went into 4lo! :wink2: I figured that I have never needed 4lo as I do not off road so i was not going to physically get under there and work on it nor was I wgoing to pay $2k to have it fixed. So I just kept trying it and now it works! I just need to keep using it every few days for a while to make sure it keeps working.

Nice!
When I bought mine I made sure 4h worked real quick on the test drive and then read later about the problems with 4L. Tried it and mine won't go in. I'm 0-8 so maybe if I keep trying it'll go

 

[eviele]

Nice!
When I bought mine I made sure 4h worked real quick on the test drive and then read later about the problems with 4L. Tried it and mine won't go in. I'm 0-8 so maybe if I keep trying it'll go

I have an 06 bought used last year. The damn thing was immaculate and drove so sweetly...I forgot all about 4lo. Bought it, brought it home and was mortified to find 4lo wouldn't engage.
I had thirty days of warranty and I tried every day for 25 days or so.
Finally, on a hot summer day I started her up and let her idle on the baking hot driveway for about 30-40 minutes periodically cycling the actuator. That did it. Somehow it seems to have softened the grease and grit enough to engage the 4lo.
The first time it went in it made a really awful sound. After cycling it a number of times the sound got less and less and the speed of engagement went faster and faster. It works smooth as silk now and I cycle it once a month.
Give it a try.