Rate my gear pattern — big weekend ahead

[LWC]

Geara and lockers arrived today from ecgs!

What are folks running gear oil wise? I was planning on using AMSOIL svg 75-90, but saw that they have a disclaimer attached saying not to use synthetic oil in their assemblies. Thoughts?

Also appreciate their note not to forget the stub shafts

 

[r2m]

I too have front and rear lockers (ARB) and am running with 4:56 (if I remember correctly...) with 35" tires.

 

[LWC]

Went 456s too. Decided to go to E locker route because in my heart of hearts I’m more of a mechatronics person than a true mechanical engineer . I convinced myself that I probably could live with the trade off of a tiny bit of instantaneous locking capability vs the generally simpler e locker design.

Edit added pic of the ifs pattern.

 

[eklipsephil]

I used the 85w140 they recommended on my 8.2 swap. Feel like they probably know best out of anyone.

 

[Rednexus]

Nothing wrong with conventional in diffs. If you do any amount of off roading or water crossings the diff fluid will get disgusting quickly. I change mine annually and it's nasty every time. I use conventional to keep the costs down, but put synthetic in the transfer case as it seems to run quieter.

 

[URJ150L]

Nitro 488 and arb lockers here… run both amsoil and royal purple before. No issues with either.

 

[LWC]

Have about 1500 miles on them now and decided to re-regear back to OEM :O, but will still be keeping the lockers (duh).

I loved the additional pick up, but could not stand the whine from the gears even though it was very faint. Neither my wife, nor nanny could hear the whine.

Additionally, as a reference point for others considering gears, on stock tires, the GX has such a smooth engine that the additional rpms from 456 gears were indistinguishable at freeway speeds (80-85 mph) from OEM gears. No extra vibrations or anything like that. They also caused the transmission to shift a bit nicer in the city. If you are less sensitive to 500 Hz-1KHz whines than I am, you will be very happy with their performance, even with stock tires.

I had my diffs evaluated by a couple gear shops in my area and TLDR, ECGS did a good job on set up, but the gears still whined due to the innate characteristics of the gears.

Apparently OEM gears are manufactured using face hobbing (aka 2 cut) whereas aftermarket gears are made using face milling (aka 5 cut). this results in a abit of a different tooth profile, where the 2 cut gears basically have the same heel depth and form a biased (diagonal shaped) pattern. In contrast the 5 cut gears have a taller heel edge than toe edge and have that straight-ish pattern that we are all used to seeing. Long story short, face hobbed gears are inherently quieter, but require more expensive machines to produce.

Revolution gears, if you're reading this, I'll buy your first set of face hobbed gears for a toyota 8" IFS/8.2".

 

[JDUB fab]

Did you have all this done at ECGS in Delaware? Looking to sell the gears…

 

[Jetboy]

FWIW - I had revolution 4.56 gears setup in my 5th gen 4R. I had a local 4x4 shop in SLC, UT setup the rear diff. It made noise. I pulled it and found that they did a pretty terrible job all around. Shop was named "Orion Offroad" and they are now out of business. The noise was immediate and they said it was normal. I pulled the diff to find that the pattern was poor. Pinion depth was way off. And they hadn't fully crushed the sleeve so bearing preload was essentially zero. (I would be very surprised to see any of these issues from ECGS - they do a ton of diffs and know what they're doing.)

I had already built the front clamshell myself and was short on time. Unfortunately good gear shops are hard to find.

I rebuilt with new pinion bearings/shims/sleeve/ and the same gears. Toyota e-locker rear diffs are dirt simple to setup if you have a good shop press and bearing separator. The clamshell took me probably 6-8 hours of messing with it to get a pattern I liked and proper backlash (and install an ARB). They had maybe 500 miles on them at that point. Anyway - after correctly rebuilding the rear diff with a good pattern, properly crushed sleeve, and correct bearing preloads - the 4.56 gears were silent. Even with street tires, there was no whine at all. And I'm pretty sensitive as well. Enough so that I ended up taking the ARB out because it was too noisy, but that's another side issue. ARB replaced it twice and I elected to just get rid of it before putting a 3rd one in.

Anyway - I think it's somewhat random luck and the 4.56 gears can be quiet. But it's probably partly luck in the gearset and somewhat luck in a setup that doesn't develop harmonic noise. All 4.56 T8.2 gears are from Circle K I believe. So it doesn't matter what brand. I think that may even include the Toyota OEM 4.56 gears for the T8.2 diff, but that I'm not sure about. If you wanted OEM T8.2 gears, they were the OEM gearset on the 2010 4Runner 4ycl model. They are still available as an OEM part despite being used only 1 year on that low production model.

In the end - I also removed them though. The reason for me was that I had a significant drop in highway mpg even with 34" tires. And I found that I was still often in 4th gear on the hills, but now I was just running even higher rpms. So it wasn't helping.

Also as another aside here - I contacted circle K (the korean gear manufacturer) in about 2019 about making a 4.10 gearset for the T8.2 (there's already oem 4.10 for the clamshell 8"). I thought that the forgings for the 3.9 pinion and 4.56 ring gear would be close enough that they could use those and make up a 4.10 gear set. They verified that they could do that and the cost would be pretty reasonable without having to make new forgings to start from. However, the minimum order for decent pricing (under $100/set wholesale price) was 200 sets, and I didn't really want to become a reseller of parts. So I swapped back to the 3.73. I kept both diff sets, so it didn't cost much other than time to swap between them either way. I still have the 4.56 set shrink wrapped in a box in case I buy another 4runner or GX in the near future. But if someone wanted to find enough buyers for 4.10 gears I think they'd be happy to make em for you. IMO that's the ideal ratio for the 5th gen 4Runner and GX when running 33-35" tires.

As far as the patterns on your gears - I think they both look on the deep side (pinion depth set for deeper gear mesh). It's probably stronger and a bit noisier with higher tooth contact. I setup might a bit shallower to be more similar to OEM gear depth. Here's the wear on the oem T8.2 from my 4Runner diff:

 

[Rednexus]

I've had gear whine in another vehicle before and it was due to a failing pinion bearing. I'm not a gear expert, but it seems like the gears should not really be whining at all. If you did have something like a failing pinion, carrier, or wheel bearing, you could have a perfect pattern but still have noise. Just a suggestion.

 

[LWC]

Did you have all this done at ECGS in Delaware? Looking to sell the gears…

I did, and if you want a bare ring and pinion I’m sure we can work something out

 

[LWC]

I've had gear whine in another vehicle before and it was due to a failing pinion bearing. I'm not a gear expert, but it seems like the gears should not really be whining at all. If you did have something like a failing pinion, carrier, or wheel bearing, you could have a perfect pattern but still have noise. Just a suggestion.

I had two different reputable shops check it out and take it for test drives. Both indicated that if they had done the gears they would’ve considered it well within normal limits.

 

[LWC]

FWIW - I had revolution 4.56 gears setup in my 5th gen 4R. I had a local 4x4 shop in SLC, UT setup the rear diff. It made noise. I pulled it and found that they did a pretty terrible job all around. Shop was named "Orion Offroad" and they are now out of business. The noise was immediate and they said it was normal. I pulled the diff to find that the pattern was poor. Pinion depth was way off. And they hadn't fully crushed the sleeve so bearing preload was essentially zero. (I would be very surprised to see any of these issues from ECGS - they do a ton of diffs and know what they're doing.)

I had already built the front clamshell myself and was short on time. Unfortunately good gear shops are hard to find.

I rebuilt with new pinion bearings/shims/sleeve/ and the same gears. Toyota e-locker rear diffs are dirt simple to setup if you have a good shop press and bearing separator. The clamshell took me probably 6-8 hours of messing with it to get a pattern I liked and proper backlash (and install an ARB). They had maybe 500 miles on them at that point. Anyway - after correctly rebuilding the rear diff with a good pattern, properly crushed sleeve, and correct bearing preloads - the 4.56 gears were silent. Even with street tires, there was no whine at all. And I'm pretty sensitive as well. Enough so that I ended up taking the ARB out because it was too noisy, but that's another side issue. ARB replaced it twice and I elected to just get rid of it before putting a 3rd one in.

Anyway - I think it's somewhat random luck and the 4.56 gears can be quiet. But it's probably partly luck in the gearset and somewhat luck in a setup that doesn't develop harmonic noise. All 4.56 T8.2 gears are from Circle K I believe. So it doesn't matter what brand. I think that may even include the Toyota OEM 4.56 gears for the T8.2 diff, but that I'm not sure about. If you wanted OEM T8.2 gears, they were the OEM gearset on the 2010 4Runner 4ycl model. They are still available as an OEM part despite being used only 1 year on that low production model.

In the end - I also removed them though. The reason for me was that I had a significant drop in highway mpg even with 34" tires. And I found that I was still often in 4th gear on the hills, but now I was just running even higher rpms. So it wasn't helping.

Also as another aside here - I contacted circle K (the korean gear manufacturer) in about 2019 about making a 4.10 gearset for the T8.2 (there's already oem 4.10 for the clamshell 8"). I thought that the forgings for the 3.9 pinion and 4.56 ring gear would be close enough that they could use those and make up a 4.10 gear set. They verified that they could do that and the cost would be pretty reasonable without having to make new forgings to start from. However, the minimum order for decent pricing (under $100/set wholesale price) was 200 sets, and I didn't really want to become a reseller of parts. So I swapped back to the 3.73. I kept both diff sets, so it didn't cost much other than time to swap between them either way. I still have the 4.56 set shrink wrapped in a box in case I buy another 4runner or GX in the near future. But if someone wanted to find enough buyers for 4.10 gears I think they'd be happy to make em for you. IMO that's the ideal ratio for the 5th gen 4Runner and GX when running 33-35" tires.

As far as the patterns on your gears - I think they both look on the deep side (pinion depth set for deeper gear mesh). It's probably stronger and a bit noisier with higher tooth contact. I setup might a bit shallower to be more similar to OEM gear depth. Here's the wear on the oem T8.2 from my 4Runner diff:

My understanding is that the main difference is the manufacturing method and the effect it has on the mesh between the pinion and ring. Basically all OEM gears are manufactured using the 2 cut process. I only mention revolution because they do make 2 cut gears for a handful of applications

 

[Jetboy]

My understanding is that the main difference is the manufacturing method and the effect it has on the mesh between the pinion and ring. Basically all OEM gears are manufactured using the 2 cut process. I only mention revolution because they do make 2 cut gears for a handful of applications

I'm with you on that. I was mostly posting that the 5 cut gears can run silent, but it's just less of a sure thing and they're probably more likely to make noise. But they often do mesh quietly if you get them setup right. And I don't mean that the setup is right in the sense of being a good pattern - just setup so they happen to mesh in a way that doesn't make noise. Which I think is a bit about just being lucky.

FWIW - I don't think Revolution actually makes any gears. They repackage and resell wholesale gears. There's only a couple manufacturers in the world and almost all aftermarket gears are from those manufacturers. Revolution T8.2 gears are manufactured by Circle K. (The trademark is a K with a circle around it. The actual company name is Samgong Gear. ) So, whether the box says Yukon, Nitro, Revolution, or whatever brand - they're all from the same place. Those are all resellers, not manufacturers. I borrowed this pic from google search, but you can see the trademark K on there. I'm skeptical that there's any difference between any of the brands. At least as far as Toyota aftermarket gears go. I doubt Samgong does anything different for Nitro than they do for Revolution. But, I could certainly be wrong and if someone has actual knowledge of this I'd love to know about it.

Toyota manufactures a lot of them in-house.

 

[JDUB fab]

Lots to think about. I’ve got 35s on now, want to re gear in the future and maybe step up in size, at a later date.. anyone know if the E lockers make noise like the ARb?

 

[LWC]

Lots to think about. I’ve got 35s on now, want to re gear in the future and maybe step up in size, at a later date.. anyone know if the E lockers make noise like the ARb?

The lockers themselves are DEAD quiet. I literally cant tell when they switch on, except the light on my switch pros goes on and obviously you feel them once you turn. It also seems damn near instantaneous. I was being a dumbass and switching them on and off while turning slightly and I could feel them lock up within a fraction of a second. I think the "elockers are slow" concern is a bit overplayed with the new generation of eaton products.

This sounds a bit crazy, but I do wish they had a second wire to provide feedback that the locking mechanism had closed (e.g. a contact sensor).

 

[r2m]

Have about 1500 miles on them now and decided to re-regear back to OEM :O, but will still be keeping the lockers (duh).

I loved the additional pick up, but could not stand the whine from the gears even though it was very faint. Neither my wife, nor nanny could hear the whine.

Additionally, as a reference point for others considering gears, on stock tires, the GX has such a smooth engine that the additional rpms from 456 gears were indistinguishable at freeway speeds (80-85 mph) from OEM gears. No extra vibrations or anything like that. They also caused the transmission to shift a bit nicer in the city. If you are less sensitive to 500 Hz-1KHz whines than I am, you will be very happy with their performance, even with stock tires.

I had my diffs evaluated by a couple gear shops in my area and TLDR, ECGS did a good job on set up, but the gears still whined due to the innate characteristics of the gears.

Apparently OEM gears are manufactured using face hobbing (aka 2 cut) whereas aftermarket gears are made using face milling (aka 5 cut). this results in a abit of a different tooth profile, where the 2 cut gears basically have the same heel depth and form a biased (diagonal shaped) pattern. In contrast the 5 cut gears have a taller heel edge than toe edge and have that straight-ish pattern that we are all used to seeing. Long story short, face hobbed gears are inherently quieter, but require more expensive machines to produce.

Revolution gears, if you're reading this, I'll buy your first set of face hobbed gears for a toyota 8" IFS/8.2".

Wonder if you just kept them on over a year or so (10,000 miles?), if the whine would dissipate. Considering that gears are tool steel and extremely hard, I wouldn't expect them to "mesh" in with 1500 miles or even double/triple that range.

You could lone them to someone to run for 10,000 miles or more than then put them back in!

 

[Washingtontaco]

I run Nitro Gear 4:88 and ARBs front and rear. No noise issues but 35+ years of aviation maintenance have something to do with it? BTW Nitro Gear has there gears manufactured by a OEM gear maker in South Korea, IDK what they do for machining but may be different than ECGS?

#tennitus

 

[LWC]

I run Nitro Gear 4:88 and ARBs front and rear. No noise issues but 35+ years of aviation maintenance have something to do with it? BTW Nitro Gear has there gears manufactured by a OEM gear maker in South Korea, IDK what they do for machining but may be different than ECGS?

#tennitus

ECGS is just the company that did the diffs. The gears themselves are Nitro. 35 years on a flight line could do wonders for your ears ;P. Heard a F-22 take off once and it was so loud it sounded like the sound was coming from inside my head .

 

[LWC]

Shot of the harmonic noise on coast. Like I said… it’s pretty mild, but there is definitely a harmonic in place. Also iPhone microphone is hot garbage , so it’s a noisy plot.