2Gen Sequoia Auburn Locker - Noisy AF Now :(

[2008Sequoia]

I installed the Auburn locker in my 2Gen back in 2022. Shortly after - approx. 3,000 - 5,000 miles later, I developed a weird and significant humming/droning sound between 55-65 MPH (it's there after 65MPH, though slightly more tolerable). I've drained the differential oil and all looked fine. No metal in the fluid - beyond what's normal. I've checked wheel bearings. All are good - and wheel bearing would have given out by now after 2 years...This sound is completely ruining the driving experience for me. I'm curious to hear if anyone else has had any issues with their Auburn Lockers creating any additional noise after installation. I've lived with it - but DAMN - it's annoying AF.
It's not tire noise either. It's a mechanical sound of some kind...

 

[LandCruisinMy93]

I installed the Auburn locker in my 2Gen back in 2022. Shortly after - approx. 3,000 - 5,000 miles later, I developed a weird and significant humming/droning sound between 55-65 MPH (it's there after 65MPH, though slightly more tolerable). I've drained the differential oil and all looked fine. No metal in the fluid - beyond what's normal. I've checked wheel bearings. All are good - and wheel bearing would have given out by now after 2 years...This sound is completely ruining the driving experience for me. I'm curious to hear if anyone else has had any issues with their Auburn Lockers creating any additional noise after installation. I've lived with it - but DAMN - it's annoying AF.
It's not tire noise either. It's a mechanical sound of some kind...

Oh boy, I'm working on the Auburn Install right now and now I'm worried. Did you do the gear setup?

 

[2008Sequoia]

Oh boy, I'm working on the Auburn Install right now and now I'm worried. Did you do the gear setup?

Yeah, I replaced the OEM gears with Nitro Gears. I kept the stock ratios since I don’t have large tires or a lift yet.

 

[gnob]

Yeah, I replaced the OEM gears with Nitro Gears. I kept the stock ratios since I don’t have large tires or a lift yet.

have you run it on stands and verified its diff noise?
iirc nitro gears are problematic. seems silly to replace oe gears for aftermarket without changing ratio.

 

[2008Sequoia]

have you run it on stands and verified its diff noise?
iirc nitro gears are problematic. seems silly to replace oe gears for aftermarket without changing ratio.

Well, I thought updating the bearings with fresh ones would be beneficial for the longevity of the differential…I wasn’t aware that Nitro gear bearings were problematic…

 

[Jetboy]

Well, I thought updating the bearings with fresh ones would be beneficial for the longevity of the differential…I wasn’t aware that Nitro gear bearings were problematic…

I think there's some confusion between what you an gnob are saying. He's asking if you changed the gears. And I think you are saying that you changed the bearings. Not the gears.

I don't know this with absolute certainty, but I'm 99% confident that Nitro doesn't actually make anything. Nitro is a reseller of products manufactured by others. They don't have a gear factory or a bearing factory. They buy gears and bearings from Samyang and Koyo and resell them in Nitro packaging. Nothing wrong with that. In fact, it would be pretty hard to buy gears without someone like Nitro buying a 500 set minimum production run and warehousing them to re-sell to you one at a time. Just need to understand that the nitro gears are the same gears as revolution or Yukon or any other brand. The only difference is the color of the packaging they come in. Or in your case bearing are either KOYO or Timken. I don't think I've ever seen any retailer of Toyota diff bearings use anything else. Both are very good bearings and should be great choices.

If you changed bearings there's a chance you didn't get one of the bearings seated or most likely for DIYs that I've seen is that you didn't get the pinion crush sleeve fully crushed. Did you remove the pinion bearings too? If so - check the pinion by hand for any amount of play in the bearings. By that I mean not backlash - it should twist about 5 degrees between engagement forward and backward. But it should not have any side to side play.

If you changed pinion bearings - are you sure you put the pinion shims back in the same way?

Did you verify the backlash after pinion crush sleeve final assembly?

Did you use use a measuring tool to set bearing preload? If the preload was set too low it may also result in bearings being too loose and the gear pattern making noise.

Any of those issues where you didn't get the bearings tight and gear pattern correct can lead to noise in the differential. The one thing that's pretty unlikely to cause noise in a REAR differential is the locker. Front is different. Front lockers can be very noisy. ARBs are noisy in front ADD type differentials because they don't machine the spider gears so they whine or grind noise when not engaged. But in the rear they shouldn't have any moving parts relative to anything else within the carrier assembly.

 

[2008Sequoia]

I think there's some confusion between what you an gnob are saying. He's asking if you changed the gears. And I think you are saying that you changed the bearings. Not the gears.

I don't know this with absolute certainty, but I'm 99% confident that Nitro doesn't actually make anything. Nitro is a reseller of products manufactured by others. They don't have a gear factory or a bearing factory. They buy gears and bearings from Samyang and Koyo and resell them in Nitro packaging. Nothing wrong with that. In fact, it would be pretty hard to buy gears without someone like Nitro buying a 500 set minimum production run and warehousing them to re-sell to you one at a time. Just need to understand that the nitro gears are the same gears as revolution or Yukon or any other brand. The only difference is the color of the packaging they come in. Or in your case bearing are either KOYO or Timken. I don't think I've ever seen any retailer of Toyota diff bearings use anything else. Both are very good bearings and should be great choices.

If you changed bearings there's a chance you didn't get one of the bearings seated or most likely for DIYs that I've seen is that you didn't get the pinion crush sleeve fully crushed. Did you remove the pinion bearings too? If so - check the pinion by hand for any amount of play in the bearings. By that I mean not backlash - it should twist about 5 degrees between engagement forward and backward. But it should not have any side to side play.

If you changed pinion bearings - are you sure you put the pinion shims back in the same way?

Did you verify the backlash after pinion crush sleeve final assembly?

Did you use use a measuring tool to set bearing preload? If the preload was set too low it may also result in bearings being too loose and the gear pattern making noise.

Any of those issues where you didn't get the bearings tight and gear pattern correct can lead to noise in the differential. The one thing that's pretty unlikely to cause noise in a REAR differential is the locker. Front is different. Front lockers can be very noisy. ARBs are noisy in front ADD type differentials because they don't machine the spider gears so they whine or grind noise when not engaged. But in the rear they shouldn't have any moving parts relative to anything else within the carrier assembly.

Thank you for the information. Yes, I was initially confused and misspeaking on the gears. I ONLY changed the bearings. No gears were changed. I had a shop do it. Unfortunately, I didn’t have a chance to get back to them after the first 500 miles or so to try and push a warranty of the work so I’m kinda screwed in that department. That being said, I will be contacting them to try and see if they can offer any help. Luckily I have a co-worker who’s friends with the owner so I don’t anticipate a big deal, but also, I have zero expectations that this isn’t going to cost me something to diagnose.

 

[Jetboy]

Thank you for the information. Yes, I was initially confused and misspeaking on the gears. I ONLY changed the bearings. No gears were changed. I had a shop do it. Unfortunately, I didn’t have a chance to get back to them after the first 500 miles or so to try and push a warranty of the work so I’m kinda screwed in that department. That being said, I will be contacting them to try and see if they can offer any help. Luckily I have a co-worker who’s friends with the owner so I don’t anticipate a big deal, but also, I have zero expectations that this isn’t going to cost me something to diagnose.

FWIW - any reasonably competent diff shop would warranty it if they screwed it up regardless of whether you went back after 500 miles or not. Professionally setup gears should not ever need to be adjusted or checked. Toyota doesn't need to re-check diffs at 500 miles. You shouldn't need to now either. If the gears are noisy - they should fix it. It's their fault. Not yours. Don't be shy about taking it back and asking them to take a look at it.

 

[Hardrvin]

Based on you stating it's a hum in a speed range, I'm inclined to think it's a gear setup issue.

 

[2008Sequoia]

Thanks for the advice. I’ve felt that all along. It was too convenient that it happened after I changed things.

 

[LandCruisinMy93]

@2008Sequoia the problem may come from 2 things in my mind. The first is they reused your stock gears, which is what I'm doing. The second is when you shim the bearing races Auburn calls for adding 0.004 to each side to preload the side bearings.

If the preload wasn't applied the whole assembly could have loosened up and the gears aren't meshing properly.

Reusing stock gears is an absolute pain. I've been working on mine for quite a while, on and off. The problem is the factory gears are worn, they have a pattern and when redoing bearings you need to match that pattern. If you fail to match the pattern you end up with some parts of the tooth in proper contact and others not. When the parts in contact wear in, you now have a gear set out of adjustment. The fix may end up being a new ring and pinion. It is making me think it may be wise to get gears now. I'm struggling to match the patterns but I'm using all toyota parts and have to order shims as I go.

 

[2008Sequoia]

Dude!! Excellent description and that’s a valid point that I hadn’t considered! I’m definitely going to be taking this back to the shop. If they do end up taking it apart, I’ll have them replace the gears. I’ve had a few other financial priorities that are going to delay me getting this handled for a month or two. At this point, it’s been making this noise for this long, I’ll live with it for the time being. I’d like to have it done before the family vacation- I don’t think I can handle this sound for ten hours to West Yellowstone!

 

[LandCruisinMy93]

Dude!! Excellent description and that’s a valid point that I hadn’t considered! I’m definitely going to be taking this back to the shop. If they do end up taking it apart, I’ll have them replace the gears. I’ve had a few other financial priorities that are going to delay me getting this handled for a month or two. At this point, it’s been making this noise for this long, I’ll live with it for the time being. I’d like to have it done before the family vacation- I don’t think I can handle this sound for ten hours to West Yellowstone!

I don't know about the gear sound on a trip to Yellowstone. I know when it flooded I was hauling work trailers to the contractors camp for the work we were starting... Driving through Idaho at 80+mph with the wind trying to sweep me off to OZ every few seconds, I couldn't even hear the music over my heart pounding in my ears. Of course I had been in a rollover a couple months prior and I was hauling brand new travel trailers and tool trailers. I could hear my boss in the back of my brain asking how I rolled twice in such a short period of time, Lol.

It's a great trip but I would suggest you take turns driving through the park. It's like rush hour in L.A. with people pulling over where it's marked not to and people driving down the center of the road and stopping to take pictures with 100 cars behind them.

 

[Jetboy]

It shouldn't be super hard to match the OEM pattern. The pinion depth should remain exactly as it was from the factory. The pinion depth is set by the shims and the pinion gear side bearing. Any proper replacement bearing should be the same net thickness as the original. As long as they re-used the same pinion depth shims, it should be within .001 depth of the original. And then it's down to setting backlash. If the backlash is set to match the OEM backlash - which it should be, the gear match should be the same. The only way you'd normally screw up an OEM gear set pattern would be to either move the gears to a new housing where you're starting over on pinion depth, not reusing the right pinion shim combination, or not getting the backlash set correctly on the carrier.

Toyota clamshells are a giant pain in the ass to setup correctly on the backlash/preload. I hate them. The problem is that you can't setup both preload and backlash any way other than guess and check. The housing flexes when you bolt the two halves together so there's no way to accurately measure the backlash until you have it clamped together. But both halves flex differently. So if you have backlash correct, but preload is too low for example - you need to add shims to increase preload. However, it might seem intuitive to add shims to both sides the same and expect backlash to remain the same - it won't. It'll move the center of the carrier a little because the two case halves have different flex amount now that you've increased the net stack of stuff you're compressing and now your backlash will be off a bit.

The threaded diffs are soo easy in comparison. For me as an experienced amateur it's like 1hr of work vs 5-8hrs.

It's possible the gear setup guy decided that close enough was good enough and it wasn't where it needed to be. or that they didn't put the shims back in the pinion to the same spot.

All of this reminds me how strange it is that we're still doing shimming of ring and pinions. Machining is so precise now that we shouldn't need to. And there are some newer axles that are shim free. Pinions come machined precisely and they fit precisely in the housings without needing any shims. They should all be shim free with modern tooling and manufacturing processes.

 

[LandCruisinMy93]

Yeah, this post cost me money....I ordered 4.88s after this post just because I don't want to have issues after installing my lockers. I'm still fighting the pattern on my gears since the locker install.