clunk, no, not the drive shaft one..

[Kanaljen]

I have this clunk, sometimes clunks, rapidly one after another..

During this, the TRAC in the dashboard flashes!

It seems like it happens more often if I brake medium, come to a stop with the foot on the brake and keep it in the brake hard for 20-30 sec, then let go and give it light gas.. Then you can here the clunk, cluck, clunk and the TRAC light flashes..

So, not the typical clunk it seems..

Any thoughts, suggestions??

Thanks!

 

[e9999]

ummm....


If the TRAC is working, that would suggest one of the wheels is not spinning at the same rate as the others. Seems highly unlikely if you're on asphalt and the rubber is not showing signs of being dragged around.
Or a sensor assembly is defective and it thinks a wheel is not spinning equally. Much more likely I would think. Have you had a look under to see if all the connectors etc are OK?

Or the TRAC could be defective of course. Not sure how you'd pinpoint the issue short of replacing the ECU and testing all the wires.

Maybe easiest and cheapest would be to start with a check of all the wheel speed sensor stuff.

 

[Kanaljen]

Thanks for the reply.

I have yet to crawl under the car, taking the wheels off to inspect thr brakes etc, but yes, that should be my next step.

It's weird.. almost like the brakes are "sticking" to the rotors and then when you take off you get this knock knock knock-type sound and the TRAC light in the dash flashes..

On a separate but related note, when driving in the sand (all while I assume the TRAC system working to make sure no wheel is spinning faster than the others), why doesn't the TRAC light in the dash flash repeatedly? Is the TRAC system turned off if you engaged the transfer case locker (manually)?

Thanks!

 

[e9999]

I was under the assumption that the clunk you hear is the "normal" TRAC operation noise. Is that indeed the case? At least on mine, when the TRAC is operating (and I think the light is on solidly) it makes this loud clang clang noise. Now, I only got it to do that once in the snow, though. I don't think it ever came on in the sand, or at least made the noise, that I recall. Must be that my system is not that sensitive or that I'm such a good driver that I never get wheels to lose traction...

 

[Kanaljen]

I'm not familiar enough with the LC (this is my first one) that I don't know if it's normal ATRAC noise or not...

But, whatever it is, I do know that it shouldn't engage after I come to a stop...

Of course, it doesn't happen every time, so it will be tough to convince the stealship to find the cause.

First things first, I'll inspect the brakes and sensors and if I can't find anything wrong, I'll be left with few other choices.

 

[LandCruisers4Life]

It's your brakes. Take it to Toyota and have them check it out.

 

[Kanaljen]

Did you have similar symptoms with you LC? When you say it's the brakes, do you mean something mechanically with the calipers or sensors feeding the TRAC and VSC controls?

Yeah, if I can't find anything obviously wrong when taking the wheels off, I'll have to take it to the dealer.

Just got it, bought it partly because of the notorious LC quality, it's a 2006 with 11k miles on it.. really don't like how this is starting off...

Thanks for chiming in!

It's your brakes. Take it to Toyota and have them check it out.

 

[NMuzj100]

You have to consider you are basically still in a "shakedown mode" at 11k. Anything that has 50k in electromechanical parts will need some trouble shooting when first put into service.

 

[e9999]

if it's only 11K and still under warranty, then by all means go to the dealer and have them record the problem even they can't see it themselves at the time. That way you're covered even if the warranty expires -which could well be soon if 3 years. (Check the fab date for an idea of the earliest it could have been sold if you don't know for sure.)

 

[Kanaljen]

Off to the stealership I guess

UPDATE

I guess I'm taking the LC to the stealership...

What I did over the weekend:
I took off the calipers and took apart anything I could to inspect, clean and lub (when applicable).

I checked each piston (4 per caliper) for wear and made sure nothing was sticking.. Each one was moving in and out without problem.
(BTW: Must say I'm impressed with the brake assemblies on this bad boy!! 4 pistons per corner, massive pads and overall very robust and well designed..)

I used about a can of brake cleaner to make sure the pads and rotors were squeaky clean before reassembly.

I bled the brakes (well, with the amount of brake fluid I passed through, I pretty much flushed my brake system...)

I cleaned the wheel sensor (For ABS, TRAC, etc)

~~~

I took it for a spin and the brakes worked nicely; no lag, firm, good initial bite, i.e., no air or issues.

But about 5 min into it, I stopped at a light, held my foot on the brake, waited 2-3 min for green, took my foot off the brake and there it was again!! A shudder, you can hear and feel it, and that TRAC light flashing for 1-2 sec). As I reported earlier, almost as if the brakes stick or the system tries to brake when I first take off.. A bit of the same feeling as when your ABS engages.. That rapidly pulsating, in this case, about 2-4 times within 1/2 sec..

I have other projects I should spend time on.. this sucks and my wife wonders why the tank-of-all-SUVs has this issue when her Pathfinder had none for 120k miles..

If anyone has experienced this, please chime in!!
Thanks,

 

[Kanaljen]

Just one more holla before the stealership..

Has anyone experienced something similar with their LC??

Thanks!

 

[kipper]

I'm having the EXACT same problem with my '01 470 and I've done all the same things you have. Every single thing you describe including how to reproduce it is the same. Cleaned/inspected brakes, sensors, etc. I thought initially it was the well known accelerator pedal position sensor/throttle position sensor issue, so I also replaced the APPS, the only thing i haven't done yet is replace the TPS, but I really don't think that's what the problem is. I'm thinking one of the ABS sensors is going bad? I do get a clunk from time to time, seems like when accelerating after a hard stop, but I'm pretty sure that's just the drive shaft. I'm going to tear it all apart again this weekend to see if there are possibly some worn bushings or bearings that could be causing this. I'll post up if I find anything.

 

[ShottsUZJ100]

The TRAC system cannot be turned off. It's always on and monitoring the wheels. The TRAC light itself ONLY comes on when the system "kicks in" and controls the brakes. The light stays on until the brake control ends. There is a time max (I think about 8 seconds) where the system kicks out so not to overheat the brake booster. After a cool-down time (under 1 minute) the system is ready again to control spinning wheels.

Something is WRONG with your system. You should not experience what you experiencing. I'll bet it's a minor thing.

 

[Kanaljen]

Kipper,

Let me know if you find something that might help!

I actually caught it on my cell phone camcorder! Didn't get the sound for some reason so I'll try again.

Just driving, standing still for a while in D and foot on the brake, release brakes and THERE IT IS...

 

[LXPearl]

Something is wrong. The only time I recall my TRAC light flashing is when I have released the Center Diff Lock and it was not wanting to release. I typically stop, back up about 10-20 ft and it usually releases.

I only recall experiencing (via beeper) VSC/TRAC once in my LC and once in my LX - LC in ice, LX in a deep wet snowfall. Compared to my 4Runner, the LC/LX is not nearly as "invasive" in its activation. When it operates, it is like the abs operation but a bit louder, and the beeper sounds. I believe the TRAC light stayed lit through its operation.

If your vehicle is under warranty, take it to a dealer for verification and validation of the problem. The dealer has the Toyota OBD scan tool that includes the ABS features, etc. and should be able to identify problems.

 

[Kanaljen]

Quick update..

Finally got time to take the LC to the stealership. The worked on it all day (Sat Morning appointment) and now need to keep it to continue work on Monday..

They re-calibrated the steering angle sensor because they said they got error codes related to that. The codes went away but my symptoms didn't..

I want my ride back pronto but only if they really fix it; none of that wrench, wrench, 10 sec test ride, seems ok now... cr.p!

We shall see..

 

[Kanaljen]

Another day passed with LC in the shop.. They now changed (I think) the front speed sensors. I guess those are the sensors sitting next to the calipers, monitoring the speed of each wheel..

Well, that didn't solve it either..

I like that they take their time but I'm starting to get frustrated because I don't feel they use the time efficiently.

Heck, buy every sensor and part even remotely related to the TRAC system, start with the easy/cheap parts first, work your way through the pile of parts until it's fixed and send back the unused ones!

Instead, they are pondering what to change, order it, get it the next day, spend an hour or two wrenching just to realize that it's didn't solve the issue, order something else and have to wait until the next day, and so forth... I think the aggressive plan for tomorrow is to change the steering wheel angle sensor...


This sucks.... I would have bought an X5 if I wanted mysterious electrical problems!!

Quick update..

Finally got time to take the LC to the stealership. The worked on it all day (Sat Morning appointment) and now need to keep it to continue work on Monday..

They re-calibrated the steering angle sensor because they said they got error codes related to that. The codes went away but my symptoms didn't..

I want my ride back pronto but only if they really fix it; none of that wrench, wrench, 10 sec test ride, seems ok now... cr.p!

We shall see..

 

[1loudLX]

front speed sensors arent hard to replace, but if they're stuck it requires removing the rotor and banging them out...ask me how i know.

 

[BManning`]

Another day passed with LC in the shop.. They now changed (I think) the front speed sensors. I guess those are the sensors sitting next to the calipers, monitoring the speed of each wheel..

Well, that didn't solve it either..

I like that they take their time but I'm starting to get frustrated because I don't feel they use the time efficiently.

Heck, buy every sensor and part even remotely related to the TRAC system, start with the easy/cheap parts first, work your way through the pile of parts until it's fixed and send back the unused ones!

Instead, they are pondering what to change, order it, get it the next day, spend an hour or two wrenching just to realize that it's didn't solve the issue, order something else and have to wait until the next day, and so forth... I think the aggressive plan for tomorrow is to change the steering wheel angle sensor...


This sucks.... I would have bought an X5 if I wanted mysterious electrical problems!!

Ouch. Are they charging you for all of these parts they are replacing needlessly? If so, that really .

Hope they nail it soon and cut you a break on the bill...

 

[Kanaljen]

Update..

Well, the first thing they did, was to re-calibrate the steering wheel angle (swa) sensor. They stated that it was a tad off but good after the calibration.

After crawling all over the car, they finally came back to the swa sensor and replaced it. I think they put back the old speed sensors since they didn't see a need to put news ones in when the old ones worked fine.. Interestingly enough, they told me that the speed sensors were slight out of range, which was the reason for changing them in the first place..

Since the symptoms are sporatic, it's hard to know right away if they actually fixed the actual issue but (since S&T is coming up and they thought they fixed it) I checked the car out last night.

So far so good... At the very least, it doesn't happen as often.. More driving will tell for sure.. I'll report back!

AND, on a good note, I finally have my 16" old LC rims wrapped with 285/75 Toyo MTs and the ride looks mean!! For those of you that I'll meet in Pismo, you can judge for yourself. For the rest, I guess I have to post updated pics..