Rate my gear pattern — big weekend ahead

[Rednexus]

You have a very quiet GX . Perhaps there is a 460 vs 470 and just the age of the vehicles/tires/seals/etc. Here is mine at 70 mph constant speed on the highway (went through this whole thing recently with trying to get rid of an exhaust drone, which is the 65 db noise). Yours seems to be a good 10 db quieter than mine, though mine is more consistent across the spectrum (could also be phone-to-phone and app-to-app differences).

I can definitely see how a gear wine would literally get lost in the noise unless the vehicle was very, very quiet.

 

[LWC]

You have a very quiet GX . Perhaps there is a 460 vs 470 and just the age of the vehicles/tires/seals/etc. Here is mine at 70 mph constant speed on the highway (went through this whole thing recently with trying to get rid of an exhaust drone, which is the 65 db noise). Yours seems to be a good 10 db quieter than mine, though mine is more consistent across the spectrum (could also be phone-to-phone and app-to-app differences).

I can definitely see how a gear wine would literally get lost in the noise unless the vehicle was very, very quiet.

My plot is probably around 40 mph, which is likely the reason for the difference in SPL, though I have heard that the 470s are a bit quieter than the 460s.

Totally stock, my GX averaged about 67db @ 80 mph on the freeway. After donating the horrid bridgestone tires it is now about 69 dB. Not a big difference, but noticeable.

 

[Rednexus]

My plot is probably around 40 mph, which is likely the reason for the difference in SPL, though I have heard that the 470s are a bit quieter than the 460s.

Totally stock, my GX averaged about 67db @ 80 mph on the freeway. After donating the horrid bridgestone tires it is now about 69 dB. Not a big difference, but noticeable.

Interesting, so I should not be complaining about my 65 db exhaust drone . Though I haven't run the sound analyzer yet in our '23 hybrid Highlander, I think it's only moderately quieter than my 16 year-old GX, (perhaps outside of the exhaust and some wind noise if the sunroof cover is open).

Other than some minor annoyances it's amazing how well these vehicles hold up and remain comfortable over time.

 

[Jetboy]

Any locker setup should be silent on the GX. Because it's AWD. The rear locker should be silent on all vehicles. The issue that I had was the ARB spider gears in the front diff are pretty crudely shaped due to the forging process. So they mesh in a noisy way. They're not machined at all I don't think. The forged gear is stronger. In an awd model like the GX - the front spiders don't free-spin in normal driving. They are rotating all together inside the front carrier and both axle shafts on the front rotate at roughly the same speed. The result is that the front spiders are static relative to eachother and there's no noise. Pretty much ever.

In the 4Runner and other models with a front ADD that disconnects one side - the driver's side remains engaged by the front left tire and with the carrier assembly not spinning, the axle shaft spins the spider gear at full highway speed (maybe 600 rpms or something like that). The carrier not being powered results in the spider gears freewheeling internally against no resistance and the spiders spin against each other - just with no load. So it's low friction. But the ARB gears end up making it really noisy. Here's a couple videos of the ARB spider gear noise. Imagine this at highway speed.





Remember that this is only a problem for front axles in part time 4x4 models. ARB paid for parts and labor to replace twice. ARB product support was very helpful - but in the end ARB RD121 is just really noisy and that's how it is. Put on some mud tires and turn up the music. Or maybe you could open up the unit and lap the gears, polish them, or ? maybe run really heavy gear oil?

Toyota e-lockers are OEM quality. Very quiet. And they don't have the same gear free wheel problem anyway. So you should never hear any noise from them.

I don't know about Harrop/Eaton units. I've heard good things. For me - I'd go OEM rear, Harrop/Eaton front if I were doing it again. But - TBH the MTS is pretty damn good. I went twice through the Rubicon in mine with MTS and never really needed the front locker anyway. It was mostly for Moab where I think it might have some relatively minor advantages. If you have MTS atrac - it's probably not all that much incremental benefit. I just did it since I was going to build a diff anyway.

 

[LWC]

I hear you, but I can also heat my gears whining . My theory is that if three very reputable gear shops, say that the type of whining I have is pretty common on regears then I’m inclined to believe them. Like I said, it is extremely faint, and if my ears weren’t sensitive to it, I would certainly leave it alone.

At the end of the day, these shops had a financial incentive to bust the differentials open and fix them, but both told me not to worry and that they’re set up properly.

 

[r2m]

i know ARB had a bad batch of front lockers that inadvertently were installed on my rig, but there wasn't any noise, they just stopped working. Wouldn't hold air pressure.
Had to go back to the shop that installed them and they had to deal with ARB to replace them. If I remember correctly the bad ones were from China and had orange rings on them (or was it the new one had an orange ring) to denote which series of lockers were bad.
Several years later, and all is still good.

 

[LWC]

Gear shop has had some....."interesting" findings. Going to talk with ECGS today to see if they can make it right, but I'm a little disturbed at what I have heard so far.

 

[Rednexus]

Gear shop has had some....."interesting" findings. Going to talk with ECGS today to see if they can make it right, but I'm a little disturbed at what I have heard so far.

Will be very interested to find out. Hopefully my regear is next year and I'm debating getting built diffs from ECGS or using the highly-regarded gear shop that is 35 minutes from here.

 

[JDUB fab]

Gear shop has had some....."interesting" findings. Going to talk with ECGS today to see if they can make it right, but I'm a little disturbed at what I have heard so far.

Definitly Intrested to hear the “findings”. Maybe we should have a dedicated gear/locker shop thread. The only one I know about even remotely near me, in NY is ECGS in NC… there must be some in the north east. I know someone over in the 470 threads sent his off to marlin. But I would prefer to just drop my vehicle off and not deal with 2 shops to get the work done.

 

[varok]

I had mine done in a local reputable SoCal shop few months ago. 4.88 Nitro gears with ARB rear lockers. Zero whine at almost 5K miles now. My buddy's Taco has the whine and was done on the different shop but used 5.29 Revolution with ARB lockers. I'm almost certain installers makes a huge difference. Even with a reputable shop like ECGS and if the installer lacks the experience, it will make a difference in QC.

 

[LWC]

I made a composite picture that shows the difference between 456 gears (light grey line), and my newly reinstalled OEM gears (blue line). The random harmonics are circled in red.

Still waiting to get things resolved with ECGS, so I'll share more soon.

 

[r2m]

I made a composite picture that shows the difference between 456 gears (light grey line), and my newly reinstalled OEM gears (blue line). The random harmonics are circled in red.

Still waiting to get things resolved with ECGS, so I'll share more soon.

View attachment 3266934

You didn't mention how the sound was to you while driving, regarding being annoying or not.
Bottom line... are you happy? It's all about what works best for you.

 

[LWC]

You didn't mention how the sound was to you while driving, regarding being annoying or not.
Bottom line... are you happy? It's all about what works best for you.

Unfortunately it was way too annoying for me, so I went back to 391s. I'm happy now that I'm back with stock gears, although I do miss the pick up and reduced low range speed with the 456s.

 

[LWC]

Ok, final update on the saga.

Looks like the "findings" were a non issue, think the local shop was just trying to be thorough to CYA. I appreciate their diligence, but it probably made me more paranoid than usual.

ECGS was a good joint to deal with. I would go back through them in the future, with one and only one caveat. If the vehicle is a daily driver that you need to minimize downtime for, it's probably not the right service to use unless you are on the east coast due to shipping times to correct issues that may arise. In that situation, I would likely use a local gear shop that can turn around the job faster. Although I think I was one of the rare people to end up with a set of gears that bothered them, I would basically factor "how stressed am I going to be if I need to pull the diffs again" into the calculation. For a car you can leave in the garage for a week, this is a total non issue.

With that said, the quality of work from ecgs was solid, they do have good customer service, and they do work to make things right by their customer.

Few lessons learned:

For 456 gears, you will need a 373 and down carrier since the gears are only available in "thick". This means that if you put a e locker in, you will need a different e locker if you decide to go back to stock since our stock gears are 391.

I"m very noise sensitive, so I probably should've stuck with stock gears, lol. If a bit more noise doesn't bother you, or if you roll with M/T or R/T tires, you're probably golden even if they do whine.

The 456 ratio is $$$$$, even on stock tires. I really wish it would've worked out, Lexus really should've geared the vehicle like this from the factory.

 

[LWC]

Ok, actual final update. Got to test out the lockers while going through some muddy washes on the way to peep at wildflowers out in anza borrego. Was nice just to be able to lock everything up and cruise through the mud on street tires with out drama and without tearing up the trail further.

 

[r2m]

Ok, actual final update. Got to test out the lockers while going through some muddy washes on the way to peep at wildflowers out in anza borrego. Was nice just to be able to lock everything up and cruise through the mud on street tires with out drama and without tearing up the trail further.

View attachment 3274401

View attachment 3274402

Never seen a black and turquoise striped wild flower before!!
Must be pretty rare. Hope you took it home and will cultivate it!

 

[OCGX]

For 456 gears, you will need a 373 and down carrier since the gears are only available in "thick". This means that if you put a e locker in, you will need a different e locker if you decide to go back to stock since our stock gears are 391.

My Nitro Gears are "Thin" 456. Purchased from ECGS.
I originally did not plan to run a front locker, So I purchased the thin ring. I ended up getting the ARB RD111 to match.

T8S-456R-NG - Toyota 8' Reverse, Clamshell IFS 4.56 Nitro Ring & Pinion. Fits 3.90 & Up carrier or ARB RD111
T8.2-456-NG T8.2-456-NG: TOYOTA 8.2' RING & PINION 4.56 RATIO- FITS 2011 AND UP E-LOCKER

 

[LWC]

My Nitro Gears are "Thin" 456. Purchased from ECGS.
I originally did not plan to run a front locker, So I purchased the thin ring. I ended up getting the ARB RD111 to match.

T8S-456R-NG - Toyota 8' Reverse, Clamshell IFS 4.56 Nitro Ring & Pinion. Fits 3.90 & Up carrier or ARB RD111
T8.2-456-NG T8.2-456-NG: TOYOTA 8.2' RING & PINION 4.56 RATIO- FITS 2011 AND UP E-LOCKER

That's good insight. I'm wondering if ecgs used the parts that they did due to availability at the time I ordered.