Mine does this sometimes (maybe 20-25% of the time)... The road to our neighborhood is a long straight one w/ a 50mph speed limit so I've gone up and down in many times switching on the fly between 2wd/4wd and have noticed it not immediately return sometimes. I'm still fairly set that it is the needle bearing going bad (or having gone bad already I guess), and hopefully will get a chance within the next two weeks to have it installed

Does anyone what production changes were made to the front diff after the production change vin?

My vehicle falls after there was a change made.

My 17 is at the dealer right now getting a new one put in. They didn't fight me on it or anything. I just took it in, presented the TSB and they said we will take care of it without even driving it. I'm lifted 2.5" front and 2" rear as well.

I did the same thing, got a new diff put in last week, although I'm actually bringing it back tomorrow to get it looked at because the sensation is still present, only it feels different now, a higher, tighter and faster vibration resonance that is actually more persistent than before.

The sensation still instantly goes away in 4Hi. Hoping they get is resolved otherwise I will be installing the ECGS bushing and calling it a wash since I got a fresh front diff at 50,000 miles.

Glad to know this fix seems to work. I will be visiting the dealership this weekend with my 2017. The vibration has been driving me crazy!

Funny thing is I agree with a lot who mentioned temperature. I'm in CT and its been in the 30s lately and its very noticeable especially the colder it gets.

Really glad that I'm not the only one experiencing this issue, but I cannot get my local dealership to take it seriously at all. They blame my tires, my lift, etc. I show them the service bulletin and they say they can't replicate it so I just deal with it.
What are the long term negative consequences of not taking care of this?

Ask to ride along with the tech. Show them the sound and vibration stops when shifted in to 4hi and have them acknowledge it is consistent with the service bulletin

Or go to another dealership and insist to ride along with the tech there.

I have a toyota dealership 10 minutes from my house, but I drive an hour to a great dealership that knows a lot about 4runners and customer service (I actually bought my 4runner there for the same reason-- much better attitude and customer service.) toyota service departments are definitely not all equal. If they won't help, don't bother with them.

As I posted earlier in this thread and in another thread addressing this groaning/vibration issue, my problem & resolution was the needle bearing. The groaning/vibration in my 2017 SR5 with 2 in lift and nitto grapplers was most noticeable when it was cold, between 35-40 mph, & would go away in 4WD. Unfortunately when I took it to the dealer, the temperatures had warmed, and the groan/vibration was not noticeable. The dealer punted - tried blaming it on the tires and alignment. I went through the effort of getting new alignment, etc. Then spent the entire spring, summer, & fall of 2018 without hearing/feeling the groan/vibration. On the first cold day, the groan/vibration “reappeared”. I took it straight to the dealer, & essentially begged them to review the TSB. The technician heard/felt the groan/vibration, however, so they replaced the needle bearing. I’ve had no issues with the groan/vibration since then.

So my dealer had gotten a hold of a new diff for me and was scheduled to complete the next day, but looks like it was already claimed by another dealer. They had to ship a diff from NY and say there are almost 40 ordered for dealers in the Midwest and are getting harder to come by due to back order. Mine is supposedly arriving tomorrow, but a winter storm could delay that. Hopefully I'll have mine back Monday or Tuesday. They did give me a pretty loaded up new Rav4, while it isn't quite a 4runner, I must say it is an extremely nice daily driver with lots of creature comforts that 4runner's don't have such as a heated steering wheel.

2019 TRD 4-Runner with under 30k started making a deep low pitch droning or humming noise at varying speeds as well as in both neutral and drive. The noise is intermittent, yet repetitive. It does go away for short periods of time and then returns. I took it in today to Toyota and they have concluded that the Front Differential is malfunctioning. Evidently this is a evolving Manufacturer Defect and there are enough cases already to bring scarcity to the Differential Part itself. There is quite a Substantial waiting period for the part. I would not be the least bit surprised to see a recall on this part if the problem becomes more prolific. Make sure you take care of this ASAP if it is happening to you?! Keep Going.

I think mine is doing this after the diff replacement as well. What did the dealer say?

My '14 is doing this as well. Thanks for the members posting the TSB's!!!

Anyone in the Boston area who has had success getting the dealership to replace the diff "OUTSIDE" of the 60K mile warranty? I'm at 79K and would love to have a dealership do this for me. I can only hope Toyota does the right thing at this point and voluntarily escalate this to a recall.

Thanks to this forum!!
T.

My service rep is a cool dude, they did a test drive and confirmed the noise is still there after the fresh diff. A master tech there has a lifted Tacoma and basically said that with any lift on these things theres a good change they will vibrate. Rep said his hands are tied from replacing it again under warranty because he thinks it will keep doing it with my lift, which I totally understand.

He and the master tech agreed that the best bet is what I already knew, and thats to get the ECGS coupler and replace the needle bearing, that is the best long term fix anyways. I went ahead and ordered it, just waiting for a bit nicer weather to install.

I'm still happy I got a fresh diff out the deal at 54,000 miles and am confident that the coupler will fix the issue.

Awesome, I would say I'm in the same boat being lifted 2.5" as well. I had a master tech do the replacement on mine and my rep is pretty cool too. The tech mentioned the ECGS piece to me as well and I will probably go ahead and do this. I will say it drives better after the new diff is in.

Agreed, mine seems much smoother with a lot less "slop" than before. Everything just feels tighter and much more solid.