Humming Sound

Hey I am new here and I have a little issue with my 4runner.

I have a 2022 4runner which I got in may and it has 8000km on it.
At 7000km I needed a new front differential. Had a humming sound coming from the front and I could feel some vibration.
After a week of driving with the new front diff the humming sound came back when I drive at speeds 50kmh and up. Also when I exelerate to 110kmh and get off the gas and let it roll it humms like I have offroad tires on it. The 4runner is all original nothing modified.
I tried 4x4 and there was no humming sound.
Had it at the dealershio again and they could not find anything. They blamed it on the cold weather. Don t think thats the issue as it is the same at plus degrees.
Anybody out there that experienced something like this too??

 

Bad diff needle bearing. Very common.

 

Yup. Mine did it on the drive home from the dealership brand new. The cold weather shouldn't be an excuse the dealer uses to get out of it, even though it’s true it happens in cold weather. In my case, it only happens in cold weather. Well, “happened”…because my noise is almost completely gone at this point after 39,000 miles.

Search “needle bearing”. There are some good threads here that will give you all you need to know.

After you read up you’ll understand your options better. Which will basically be:

-having the dealer keep replacing diffs and maybe eventually getting one with a needle bearing that stays quiet.

-just cut to the chase and have the needle bearing in the diff replaced with the ECGS bushing. This has solved the problem for good for everyone who has done so. The dealer will not do this.

-

 

Thanks for the reply's guys. Very helpful.

 

2018’ SR5 w/ 31k miles. No humming yet.

 

So, I just picked up my 4runner after they replaced the front diff for the second time. The humming sound is still there and I think even worst than before. Might have to follow Mcspazatrons advice and just get the needle bearring replaced.

 

I guess Toyota finally put a stop sale order on the front diffs and they produce a whole new batch which is available in around 3 month. According to the Dealership.

 

I would be pretty aggravated if I had a brand new defective front differential installed and then tossed around like it’s normal. I noticed mine at 100 miles, replaced at 950 and was good when sold at 7,000. Hopefully stays good for the next owner!

 

So In september 2023 they put another front diff in
Should have been a new batch they said. It went again just before christmas. In the shop now for another new one. Is it worth getting the dealership to involve toyata ?? The dealership would have to start the paperwork to vet the factory/toyota involved.

 

I have a question on that, as I may need this fixed, too. My 2019 is at 130k miles, and it's making noises that hint toward the needle bearing. My tech brain tells me a needle bearing assembly will roll on its shaft (CV axle), keeping wear to a minimum, whereas the ECGS bushing is a sleeve with no moving parts. In that case there are two stationary parts rubbing against each other. Maybe there's adequate lubrication to prevent wear on the bushing/axle? I'm simply curious as to how the bushing holds up longer. Do you have experience with it long-term? Thanks.

 

You should pose your question to ECGS. I've wondered the same thing, and it seems they would be the best source for that answer.

One thing's been verified by users of the bearing - there's much less play where the CV shaft rides in the differential with the bushing.

 

I don't plan to do it myself, but I've seen so many recommendations for this on the forum that I half assume it's a good long-term solution. My next step was going to be to see if the dealership would make this substitution.

 

I've not seen anyone disappointed with the ECGS fix, but also haven't seen anyone who'd convinced a dealership to install the bushing.

 

Cold weather irritating Issue. Will go away when its warm.
If not fixed now whilst its cold. Forget it.
Cheers

 

And if not, I probably won't push it. If the next needle bearing will go another 130k, that's going to take me 7 or 8 years down the road.

 

Have you verified the noise goes away when putting the TC into 4H?

 

No, it is very intermittent and I haven’t been able to test that. It happens for a few seconds at a time. Started with this recent cold snap. So if it’s that, I’m probably in the early stages of it. I do plan to do that once I figure out how to get it to happen regularly.

 

Jesus this craps still going on

 

I don’t have personal experience with it since I haven’t installed it. A buddy who works with machining and industrial equipment told me that type of bushing used by ECGS is fairly standard for this type of application.

The needle bearing should support the axle shaft evenly across the width of the needles, but I think that is essentially the problem here…they don’t because the axle has too much space to float inside bearing. My understanding is that inc4wd, the axle is driven by the diff, so it doesny float. But with 4wd off, the axle is driven by the wheel, allowing it to float around in the bearing and puts load on the ends of the needles. The ECGS bushing has a tighter fit into the axle, so loads should theoretically be distributed better across the face of bushing. Oiling is a question I have myself. But maybe this material requires less oil…not sure.

Update on my needle bearing, the noise is back after I increased the preload/ride height on the front suspension back up (because it sagged after installation of skidplates). This needle bearing is very particular to cv angle. It seems mine is quiet when the angle is zero. Zero angle seemed to happen for me with about 1.5 to 2 in of lift compared to how mine came from the factory. I’m slightly above that now.

 

@Johnny99
Man, I feel for you. Please continue to keep us up to date.
@McSpazatron is a great resource
Thanks guys, I have humming too that I don't believe is just my tires. Added a 3/2 lift, load E 285's on 9" wheels, 1.25" wheel spacers... ECGS!
I'm actually gunna test 4wd humming difference tonight thanks for that

 

Are you sure they are even replacing them? I would mark them in a hidden spot and verify next time.

 

This^
Greasy ppl, they are

 

Thanks for the explanation. Too loose a fit on that needle bearing makes sense.