9800 miles & Humming noise

The damper came in and I dropped by the dealer today so they could install it.

Verdict: It might have dampened the noise, but I can still hear it clearly.

 

Got a picture of it installed?

 

Not yet... but I will try to put it up on ramps and snap a pic in the next couple of days and post back.

 

Are you satisfied with the result? Did they show you the replaced part?

 

No, I am not. It is still humming and now its making the humming noise in a cycle (think bad wheel bearing HUM-HUM-HUM-HUM). Super annoying. I have an appointment to have it looked at again.

There was no replaced part; the TSB adds a "dynamics damper" to be bolted onto the front diffy to absorb harmonics. There was nothing in its place prior to being added.

 

Here is a link to the TSB for 21-24. Note based on front diff build date you either get a new diff or a damper and the damper is added, not replaced. Also note that if you get the damper the last step is to verify the noise is improved not gone

https://static.nhtsa.gov/odi/tsbs/2023/MC-10245450-9999.pdf

 

what are you going to do next? I am in the exact same situation with my 2024 SR5 Premium with 11k on it. The humming is annoying.

 

Maybe this is what I'm hearing as well. I've noticed when I keep my radio off (which is usually never), I hear a noise at Idle... Goes away when I accelerate. What are some simple tests to see if I can diagnose if this sound is the same thing or normal engine noise? Read earlier that throwing in 4 wheel drive and seeing what it does at idle is a good test. My 4runner only has 5,000 miles on it so maybe this is normal. I did also notice the "Squeak" noise when pressing the brake, but have written this off as normal as I've gotten used to it.

 

What has been discussed in this topic is a humming noise while driving, not idling. It is most noticeable between 45 -> 25mph. So when decelerating (taking the foot of the gas or also remaining the speed)… at least, that what I do notice, and what I do not want to hear with a Toyota!

 

Thanks. I think what I'm hearing is just the standard noise the engine makes. I'm sure this will jump out at me more.

 

Back at the dealer today… the service guy said they try the damper first per the TSB and if that doesn’t fix it, then a differential replacement is in order. All I know is I drove it to my cabin over the weekend and it got louder over a wider range.

 

I am going back to the dealer on Tuesday to “look” at it again. The dynamic damper was installed on mine with a small improvement, but it only addressed the symptom, not the root cause. Basically, it is just a bit quieter, but it didn’t fix the issue. If after this next round, i am not getting the results I am hoping for ( a normal road noise everyone else has ), I am going to upgrade the needle bearing with the ECGS bushing. That seems to fix the issue; at least I hope. Good luck to you and please let me know what Toyota is offering you. Thx

 

I appreciate that there is a TSB etc etc but the diff does not need to be replaced.

As others have said, this is the needle bearing and the only "forever" fix for it is the ECGS bushing. If you get the diff replaced you are getting a new everything to include a new failure-prone needle bearing, so while it may be fine after that it also may not be. I realize this is a warranty claim for most people so you have three choices other than having the dealer just throw parts at it: try and convince the dealer based on the voluminous data available online to replace the needle bearing with the ECGS bushing and do the labor under warranty, you pay for the part and they do the labor (good luck with that); or do it yourself; or pay a reputable shop to do it. When I replaced mine I think the shop charged me 2 hours of labor, and even though I was under warranty it was the most practical best option to just have it done and done right.

You can search this site for a ton of data about the issue and some of that may be very useful in trying to convince the dealer to do the ECGS swap.

 

I’m curious about this. I haven’t had any problems yet, but my technical brain has trouble understanding how a sleeve style bushing receives lubrication in that location. I’m thinking that the shaft rotates inside of the bushing, is that correct? I imagine the needle bearing is greased? I realize it’s a loose fit, which is the original problem. Sorry, I’m probably missing something.

 

It is filled with oil/lubrication. When you remove the axle, oil is dripping out. So under normal circumstances it is lubricated.

 

Thanks. I suppose I could look for videos too.

 

They called me about half hour ago and said that Toyota won't replace the front diff because its not loud enough But the advisor got my permission to keep it overnight to see if he can get it to be louder first thing in the morning when its really cold.

 

yup, that makes sense. I am expecting something similar in my case but maybe I will be totally surprised by my stealership. I actually bought a Toyota to be worry free. I did my research before the purchase but totally missed this issue. However, if the noise can be fixed with $120 in parts and 2h of my labor, I will just suck it up and fix the problem.
Keep us posted please.

 

Do you think it will be louder on a cold morning test drive?

 

hmmm not sure… sometimes it’s loud, sometimes it’s not so loud. Of course with the 4wd on, it doesn’t make any noise. But I can’t seem to figure out the pattern of why it’s noisy sometimes and not so noisy other times.

 

I lately noticed that the rumbling changes when I apply the breaks. This does make sense. In 2WD the front axle spins freely and with the breaks applied the weight distribution changes hence the noise will change too. Also turns make it louder. Going from 2 -> 4 and back to 2WD will change the noise too. This all makes sense to me but will be different from runner to runner depending on the play between shaft and needle bearing and with which tolerances the parts were manufactured. The parts have an allowed tolerances and if you are lucky, you may have a needle bearing with upper and a shaft assembly with upper tolerance, hence hopefully less play.

 

Yep. Mine definitely gets loud when I am braking or on a sharp-ish curve.

 

Hope all goes well tomorrow!

 

Thanks!
By the way, does anyone know how long can one drive on a humming/vibrating front different slash needle bearing before the thing grenades? Or will it just hum/vibrate along indefinitely?

 

Probably the better part of forever, honestly. I think one guy, maybe, posted pics of his bearings having redistributed themselves in pieces but I bet there's 50,000 4Runners driving around right now with the issue that the driver's don't even recognize and they are all pretty much unscathed. If you are handling it I wouldn't worry about putting another few thousand miles on it in the meantime.

 

@MyWyfsRnnr has replaced countless needle bearings with the ECGS bushing, even made videos of the process. I would do a search for him on this subject.

 

My needle bearing was making noise brand new on the way home from the dealer. Over the years I noticed it’s typically noisy in a particular temperature range (typically somewhere between 20 to 50 degrees F). Otherwise it seemed quiet. Sometimes I don’t hear it for months. It was quietest when my front end was lifted to the point the CV angle was flat. Anyways, my 4runner has 75,000 miles now.

 

Out of the tons that I've done, I've only had one where the race that holds the needles in disintegrated and the needles ended up in the diff when driving. It is more common for the needles to fall out of them once the axle pulls out while doing the bushing swap if they've been driven on a long time. I've had to count the needles more than once to make sure I got them all when I pulled the axle.

 

Has anyone tried this?

https://eastcoastgearsupply.com/i-8...ing-eliminates-needle-bearing.html?q=bushing+

 

I'm guessing you haven't read any of the other responses above...