Needle bearing issue?

You're a lot more tolerant than I am to have put up with it that long. There is a bit of space behind the bushing, like enough room to get a puller in there to remove it, that probably won't happen. The guys at ECGS said the life of the bushing is roughly 400,000 miles, we have never had a vehicle with that kind of mileage, so I'm thinkin' it is kind of a permanent fix. But realistically, a person should never have to remove it, the odds of putting 400k miles on it are very slim.

 

I’m tolerant or lazy, one of the two lol. I looked at the ecgs bearing I have (still in the box). I think the problem with pulling it like the needle bearing, is that the bushing material actually extends out past the steel casing (by maybe .5mm). I’m assuming the bearing is made of some sort of sintered material that would fracture before it starts to touch the thin outer wall of the case. I think once @mywyfsrnnr experiments with it, he would be able to see if the sintered material holds up to a puller.

But yeah, I do agree, it’s probably academic since they seem to last as long as everybody says.

 

I hear you. And I know ECGS has a good reputation and makes a nice product (I installed one of their sets).

But I'm sticking with bushing and bearing pulls, even blind ones, being bread and butter jobs.

I've built, repaired, machined enough engines and transmissions of many vintages to feel pretty confident this isn't some special bushing that's going to shatter or crumble when I go to pull it. Looks like a bi-metallic bush to me. Have done plenty of those with softer internal material and harder sleeve material.

But I'm stubborn and am also willing to be wrong. Not trying to win any arguments here.

Jason

 

My brother has a Tacoma with the ECGS bushing. He has 170,000 miles on the bushing and no issues yet. He even removed his lift recently and put it all back to stock.

 

Would a bad needle bearing be heard during idle? I recently have been having a growl or vibration coming from what seems like drivers wheel area. The noise can be heard occasionally while driving but also sometimes during idle right after starting the 4runner

 

No. The bearing makes noise due to vibration from the axle not spinning stable in the bearing

 

You would feel it between 25 and 40.

 

I am talking to various shops around Minneapolis looking for a competent tech to replace this needle bearing. The best and really only competent fellow I find and spoke to stated if there is any glitter, metallic shavings present in a fluid sampling he would only replace the entire differential as an assembly, the same route the Toyota dealerships promote, implying the entire assembly has been compromised with debris.

What's the likely hood he'll find metallic bearing debris in the fluid sample? Vehicle has 42K now and I noticed noise about 3-4K ago.
If he does find "glitter" should I replace the entire assembly for $4K or find another resource to replace just the bearing with the ECGS equivalent?
Thanks in advance for any thoughts.

 

@MyWyfsRnnr - any thoughts on this? I know you've replaced quite a few.

 

If the needle bearing let go and you have shavings in there then yeah, a rebuild would be a good idea because metal everywhere in the gears and bearings obviously is a bad thing. In my experience, the axle usually just beats up the cage the needles are in more than the needle bearings themselves. I have had a full failure where the needle bearings went into the diff and a full replacement/rebuild was required. Most likely you won't have that situation but 3-4k miles on the vibration worries me a little. The other thing I would consider is the acceptable amount of "sparkles" is subjective. There will always be sparkles in gear fluid, especially in a limited slip system. If you trust them then you should be okay with their diagnostic. If they are slow that month and are looking for some income and are not 100% trustworthy then they could interpret normal wear as more than that.

Thanks for the tag. Was out in the mountains all day with my kid haha!

 

No

 

Thank you all for the assistance and your comments.
I think I will move ahead with the diagnostics asap based on your concerns and see how things play out.
Thanks again!

 

Another Needle Bearing/Bushing swap today... I confirmed vibration myself before and that it was fixed after.
2023 4Runner SR5 with 6,800 miles, 275/70/17 KO2's on stock height.

 

Just curious - do you have to drain or refill any diff fluid as part of this job?

 

Yes.

Drain. Pull bearing. Install bushing. Refill. Button up.

Jason

 

Do you recommend going the warranty route first? My ‘23 started to exhibit the needle bearing vibration around the 200 mile mark.

 

Dont have to do a complete drain... You only loose 1/2 qt if you do it on level ground. Not saying you shouldn't drain and refill but you don't have to.

 

Just depends on if there is any damage/sparkles in the fluid. It is unlikely but draining the fluid to check is not a bad idea, if the fluid is clean then just do the bushing, if it is sparkly, warranty, then do the bushing. Warranty will only install a new/rebuilt front diff with the same Needle bearing. They did not/have not fixed the issue with the "updated" diff they would swap in.

 

Gotcha. Thanks.
Any strong theory why some purport to not experience this issue until after many thousands of miles, and some experience it much earlier?

 

PS @glwood54 , I have not forgotten about doing a video, the person yesterday was in a rush so I just did the swap quick for them so I didn't have time to film it etc. I have one coming in soon and I will film that one and link the video here

 

Look up this thread at posts 319, 282, 220, 204, 198, 180 & 178 for my opinions (which aren't gospel) on this.

 

No rush. Whatever works with your schedule, thanks.

 

Judging from my experience at different ride heights, a small difference in height could be the difference between noisy and not noisy. My bearing seems to be quiet when the cv shafts are at 0 degrees of angle. When mine was new, my cv angle was slightly negative, and it made noise. It stayed the same when I lifted and the angle went slightly positive. It was quiet when my cv angle was flat as suspension sagged with the weight of armor. And it came back when I lifted the front back up to compensate for the weight.

 

wow great analysis! This makes a lot of sense and would explain the weak patterns in the reports we have seen.

This mean the stance of the vehicle, due to weight would also impact the reproduction of this problem.

 

Yes, In theory anyways lol. So in edge cases, theoretically, the angle changes caused by passenger weight or fuel quantity could set off the sound.

I’m spitballing here based on what I’ve read and what I hear/see with mine, but it seems the noise is due to how pressure from the cv shaft is distributed across the width of needle bearing. My logic is that any cv angle means the part of the shaft riding in the bearing will put more load on either edge of the needle bearing. And the large shaft/bearing clearances may allow the other end of the bearing to be completely unloaded. Pressure on an end of the bearing will be louder than if the shaft lays perfectly flat across the entire surface of the needles.

But, theories arent always perfect. The clearances between shaft and bearing could be causing resonance/harmonics independently from angles.

I’m kind of convincing myself to replace my needle bearing with another OE bearing when mine gets too loud. For science. Eh, maybe not though… too many variables lol. Maybe once I dial in my suspension to the ideal height, because I’m a smidge high right now.

 

Have you tried the higher viscosity gear oil theory yet?

 

I have not, but I thought I read others tried with no difference. If the noise mechanism is “point loads at the edges of the needle bearing, I would guess viscosity wouldn’t make that much difference.

 

The clearance between the shaft and bearing are a huge part of the "flutter". The ECGS bushing is a much better fit as far as bushing/axle clearance. We've had ours in now for around 25,000 miles, just as smooth and quiet as the day it was installed. For sale: 1 brand new looking needle bearing!

 

At what mileage did you install it.

i still have a non zero reservations due to mfr warranty concerns

 

About 3000 on the odometer. Yes, we have 28,000 on a 2020. Not trying to be rude, but what warranty issues would arise? No, I'm not sure, honestly. Toyota's cure is to throw a $2,000 + whole diff. for warranty. Don't tell them you have a bushing in.. they won't look.. Toyota has had 10 yrs. to fix this situation, they're 'tight' when it comes to spending a dollar for someone to 'look' for a reason to deny a claim, but will spend $2000 for replacing a diff.. what the heck.