whats that noise in my tundras rear end

2003 Tundra AC t3 edition, 2wd automatic w/LSD

so I'm trying to track down (and remedy) a weird noise coming from my rear end. it's like a clack/click when coming to a full stop, and taking off from a full stop. it's not a heavy clunk feel, more just noise. doesn't happen every time, but a lot. so might be when i get the drive line unloaded, and loaded back up, or something else. happens when going straight and turning. seemed to disappear in winter. that could just be me paying less attention, or cold air eating sound, windows up. or the cold thickening something up. Rear seat has been removed for a long while, so the cabin is a bit louder than normal.

pretty sure it's not the drive shaft, as that was rebuilt 8 months prior to me noticing the noise. seemed to start around the time i replaced the rear diff oil, but i did also replace the rear brakes 2 weeks after that. so similar time frame. sticking a camera under there is various places did not help narrow it down. my thoughts are the rear diff does not like the synthetic gear oil, or the brake shoes are moving/binding.

related repair/maintenance
Oct 3, 2023 226575 miles
Driveshaft rebuilt and balanced (new spicer carrier and u-joints) joints greased with oil changes

June 12, 2024 230038 miles
Rear diff oil drained and replaced. filled with Amsoil severe gear 80w-90 synthetic. (amsoil also recommends

$39 75w-90 GL-5 Limited Slip, Ultra Long Drain 500k Miles, Manual Transmission, Gear/Differential Lubricant (1 Gallon)

75w-90 and 75w-110. toyota manual asked for 80w-90 conventional)

June 30, 2024 230261 miles
Rear shoes, drums, hardware, wheel cylinders replaced. backer plate slide points sanded and greased. backers plates are pretty rough as she is a rusty rusty Canadian girl.


Any Thoughts, Ideas, Recommendations welcome. i'd love to get this particular noise dealt with

 

You need LSD additive for that oil, or better yet, just drain it and fill with Lucas or Motul 80W-90. That AMS oil doesn't work properly out of the bottle for LSD trucks.

 

As you will find in the thread "Everything you should know about your 1st Gen, so read this shit already!" thread, the 2WD trucks were plagued with cracking transmission crossmember. Here's the TSB, and here's the thread that the 1st gen info thread directs you to which covers how to verify and what to look for. It happens, A LOT.

When the crossmember cracks, the bolts usually back out, then fall out. The result are the exact symptoms you're describing, and usually, within 5 seconds of sliding under your truck, and checking for either (A) absence of those bolts and/or (B) whether the bolts are movable by hand will tell you if it's your problem.

Slide under your truck. Find the transmission crossmember. Look up inside the ovular hole in it, to verify all four bolts are intact, the bolts aren't loose, the crossmember isn't cracked.

 

Just a bit of counter on that: We have a couple of folks on here who've used Amsoil Severe Gear and listed it as one of the synthetics which is compatible with our LSD rear end. That and Valvoline Advanced Synthetic in the Flexfill packs.

 

Ah, I couldn't remember exactly which AMS oil you had issues with or w/e

 

I had to dump brand new Mobil1's full synthetic. Even using additive didn't get right of the chatter I was feeling when backing out with wheels at full lock. It diminished it, but with how much I had to add to get it 80-90% gone, I had concerns about the clutch packs being unable to catch if I ever needed them to. Possibly irrational fear on my part, but ... when M1 told me they'd reimburse me for their product that wasn't working for my truck, no questions asked, I decided dumping and using a conventional 80w90 like Lucas was the better option.

 

bolts are all there, and tight. I've check previously, probably after reading one of your posts. i will double check either way. are the cracks usually around the bolt holes?

Broooo, i got excited id get to spend more money of more gear oil, and now my choice of Amsoil synth may in fact be fine? do you know if they needed an extra additive, or just running is as is?

 

I'm definitely not adverse to dumping the amsoil and running the lucas. even if it's unrelated to my clack sound. my noise, this one anyways (there are others) does happen when going straight, like from a stop light. i don't really have a frame of reference for what "chatter" in the corners sounds like though.

i'm assuming the lucas is the 10043/20043, and no need for extra addative? (why they have a different one for the Canadian Market, who knows_

 

That linked thread will show the typical cracks. Some people on here who've had the issue noted the cracks weren't easily visible from the bottom, but much more so from the top. Some of the pics in that same thread would potentially support it.

Like, this is what was visible from underneath, a tiny hairline that I'd have needed zoomers, or at least readers on, to be able to see: https://tnstatic.net/attachments/img_0796-jpg.1023404/
This is what that same crossmember looked like from above, where it was bolted to the transmission: https://tnstatic.net/attachments/thumbnail-jpg.1023407/

Side-by-side top vs. bottom:

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If you're not specifically experiencing chatter, DO NOT put additive in your gear oil. That Amsoil Severe Gear already comes with slip additive in its additives package.

If you don't know what chatter feels like, I'll do my best to describe it. It's almost like a "skipping" feeling. Like, if you were to drag your thigh across a hot vinyl seat, that skip-skip-skip-skip sound, almost like a mild fart escaping your lightly clenched cheeks, that's kinda what it's like.

You will usually only experience when doing sharp turns, as you begin to accelerate from a full stop. In the vehicle, you may hear a nearly inaudible skip-skip-skip-skip sound. It's apt we call it "chatter", because it's almost like what it would sound like if two fibrous pads were skimming over each other.

The sound will be rhythmic, and usually be no less than 4-6 taps, equally separated. It happened to me most when I backed out of a parking space at full lock, when the vehicle was cold. But I would occasionally feel it while turning hard out of my neighborhood from a full stop, also when the truck was cold. Once the truck was 1/4 up to operating temp, I usually wouldn't feel it.

If what you're feeling is just a random, single CLUNK/THUNK when accelerating from a stop, it's likely something between the transmission mount and the gearbox. With you having a 2WD, naturally, the TSB and forum members here don't lie, it's quite possibly your transmission mount. If it's not the transmission mount, it may be a U-joint, or potentially the carrier.

My advice to you would be, get under the truck, grab the rearmost driveshaft firmly, and try to move it front-to-back (not up and down). Any play/clunks? Try again with the shaft between the carrier and transmission. Any play/clunks? I'd then go to your u-joints, grab the shaft on either side of each U-joint, and try to push/pull in every conceivable direction to look for play. Your OEM/factory U-joints will be sealed (because 2WD are that way), it's possible one is dry, this test will tell you if it's a U-joint.

If you have a GoPro or similar camera and can mount it either magnetically or otherwise and point it at your driveline while driving and reproducing the noise, it may also highlight the culprit.

 

See last post.

I wouldn't dump that Amsoil. They make superb products, and the interval on change will be 3x longer than Lucas. Lemme grab the part number, I'll edit this reply with it in a sec.

EDIT: This is it: https://www.lucasoil.com/product/heavy-duty-80w-90-gear-oil/

But again, as someone who threw away like $60 USD in gear oil due to incompatibility, I don't recommend throwing money out the window. Go buy a new diff breather if you haven't changed yours in the last 50k miles.

 

okay, that definitely helps me know the kinda cracks I'm looking for. time to get the ole snake cam out. very unlikely it's the drive shaft. i had it rebuilt and balanced a year and a half ago (maybe 7500 miles). new spicer carrier and new spicer u-joints. shop recommended the grease-able ones and not the original nicer sealed ones. they get greased every oil change. i crawled under there last friday to double check the bolts that tie the shaft to the rear end were still tight, and greased everything while i was under there.

 

If you have chatter, you'll know it.

I wish there was a "chatter simulator" you could share with people. It's super recognizable, but until you feel and hear it for the first time, it may not be blatantly obvious. There are probably people on here who currently have chatter, and dunno what it is.

There are other things you can do on your vehicle that resemble chatter. Like, sometimes when you release your e-brake, if the truck moves, you may feel your brake shoes chatter against the drums. Sometimes it has a high-pitched skippy BRAAAAP sound to go with it. That's the most recognizable thing I could mention which I believe most people can relate to. But chatter is, depending on the rear end we're talking about, very similar to that, although not as loud, maybe not even half that loud.

Does that ring a bell, when I say "the skipping BRAAAP sound your truck sometimes make when releasing the parking brake?"

 

Didn't mean to send y'all on a tangent because I mis-rememberred gear oil brands, but I'd check the cross-member first as posted above.

But you can always jack the rear end up from the differential and then put the truck in gear to see if there is rotational noise in the rear end that changes with RPMs. If there's a chirp/ chatter in your rear end however, it won't always show up with the truck off the ground.

 

Lol, this truck has already been through that fun time when she was my dads. passenger side axle seals in may of 2015, and a whole driver side axle in june of 2016. dealership got some good money for those. so since then, my dad has mentioned the breather a lot. i always give it a little twist when i'm under there in the area. she got a brand new one, and new fill and drain plugs when i did the diff oil change.


as for the chatter, that's not really ringing with me. any time someone mentions it, i think of the feeling you get when a 4x4 on pavement is getting all the traction in a tight corner, and you can feel/hear the tires skipping.

no worries, more info/ideas are always good. i'll get into work early one day next week (working indoors, with all my tools, outta the heat is so much nicer than in a driveway), and i'll have a real good look at the cross member. i'll grab some video of the rear end in the air and moving. i know there is a bit of "play" when i rotate one tire back and forth before the drive shaft and other tire moves. i'd assume that's just the way it is. the video will make what i'm talking about clear.

 

I made that mistake. Once. Was driving in the rain in 4HI, and pulled into a (covered, bone dry) parking lot, forgetting about 4HI. Well, when I stopped, then went to turn, I quickly remembered. POP POP POP! Way louder and more substantial than chatter. And half (or less) as many pops/skips.

Don't discount the stupid stuff, too. Like the leafs in your leaf packs slapping or skipping across each other. Each leaf should have a little disc-shaped isolator at each end, to hold them apart from the next leaf. Sometimes they fall out and will cause noise. Only other idea I've got w/o more info.

​

 

Lastly if you end up jacking up the rear of the truck and putting it in gear to check for noise, make sure you hold the brakes and make the wheels fully stop before you put it back in park. Seems like a dumb reminder, but since the truck isn't moving, your brain will put the truck in park too soon out of habit if you're not careful.

 

Crawled under her for a minute at work. vids should show the little bit of play in the tire rotations (i'm assuming that just how the rear diffs in these be) and maybe i found the noise

tundra rear end noise1.mp4
tundra rear end noise2.mp4


also in the first vid, you get a decent glance at one of my leaf packs. those spacers seem to be there mostly, maybe some of the keepers that sit in the holes are mia. and maybe some of the spacers themselves are mia. or super super flat. couple of them look more square/rectangular than round.

 

2nd video, 27 second mark. That's WAY too much play in your u-joint. That thing is fucked.

Notice how the end going into the trans output shaft isn't moving, but the shaft is totally moving like 1/8"? That's not normal. Those two shouldn't be able to move separately from one another, period. Not like that.

EDIT: If this is your 1st u-joint replacement, you may want to replace them at same time. Go with Spicer/Dana brand, that's what OEM was.

 

the output shaft is moving though?. the black part. might be the 720p video quality too, the ones i posted were rendered at a low res. and at one point around the 27sec mark i'm moving my phone while wiggling, it looked "off". i'm gonna put a gauge on all three of them on monday anyways, as i really never trust other peoples work. u-joints are easy on the 2wd shaft. those however are less than 2year old spicers. i took the whole shaft into a driveline shop to get the carrier bearing and the joints changed and a shaft balance. original 20year old carrier bearing was getting close to kaput, but original u-joints were still solid. had them changed because why not. they used the greaseable ones (5153x), not the top tier sealed ones that i believe were the oem (51310x).

also just ordered a "cheap" set of chassis ears off Amazon. maybe useful. (i don't know why the forum added a hotlink to the word "amazon")

if anyone is bored and has some time to kill, here is a video i made to try and capture the "sound". just hung my phone out the window, and did some full stops and starts on my way home. if you turn the volume up to here the clicks, make sure you turn it back down when the phone goes back in the cab. it picked up my voice hella loud.

tundra clack sound.mp4