Tacoma 6-Speed Manual Trans. Rattle over Bumps Solved! ...By Accident

First, I'm new to forums, which means I have little knowledge of how they work. I posted this on an old thread that was last visited in 2012, so not sure if anyone will ever notice. Actually as far as I know I may be talking about something already know, but perhaps someone will find it useful. ...I'll just get on with it.

Bought my 2011 Tacoma 4x4 Double Cab 6-Speed Manual new. From day one it rattled over small bumps anytime the transmission was not under load in gear, or when coasting over bumps at slow speed in neutral, primarily at low speed. Washboard roads made me think the trans. was going to fall out altogether.

Numerous trips to various Toyota shops, searching for lose brackets, mounts, fittings, etc. were made to no avail. They even said they changed out the Throw-out bearing at 50,000 miles. It made no difference. ...I'll get back to that in a second... I complained so much to Toyota they gave me a free Platinum Warranty of 6-years or 120,000 miles ..or there about. Good thing as when I finally discovered the source of the rattle the manufacture warranty had expired.

At 67,000 miles my throwout bearing (TOB) (second one) started the typical squeaking/churping sound they make when the clutch is totally disengaged in neutral. It had just started but figured why not make Toyota change it out again. I had read about the continual problems with 6-speed TOBs and how the cause was grooving of the aluminum bell housing shaft by the steel TOB. So, rather than have the shop replace the stock TOB with another stock TOB, I bought the TOB upgrade and repair kit (mine came from Underdog Racing) which comes with a stainless steel sleeve that slides over the hollow aluminum bell housing spindle. Now I have steel riding on steel. and what the heck??? My aggravating rattle for the past 5 years disappeared! Oohrah! What a heck of a bonus!!!

So, why did the rattle disappear? I can only speculate. Perhaps the "hollow" aluminum bell housing shaft sets up and magnifies the rattle of a steel stock TOB that has just a bit of slop allowing it to bounce around when bumps are hit? Perhaps the rattle is eliminated by having a stainless steel sleeve over the hollow aluminum spindle that is part of the bell housing? Perhaps the fact the TOB provided by Underdog Racing having grooves, or slots, on the inside to act as a grease reservoir (Toyota's don't) allows grease to fill the slop between the steel bearing and steel shaft it rides on, thus eliminating movement (rattle) between the two on bumpy roads?

I simply don't have time to spend finding the answer of why the rattle stopped. I'm just happy it did.

As a side note, the steel sleeve over the bell housing spindle is supposed to "eliminate" the TOB problem permanently, ...which is why I had it installed. Only time will tell if that is an "alternative fact". I can say the TOB upgrade and repair kit allows the clutch to move noticeably smoother.

I'll leave it to others that have the rattle to confirm my observations. But assuming the Toyota shop who replaced the TOB at 50,000 attempting to eliminate my rattle, replaced it with their stock TOB (and why wouldn't they) it did nothing to stop the rattle. That see,s tp confirm there is "something" about the TOB upgrade and repair kit that eliminated the rattle. It also means the stock steel TOB riding on the aluminum bell housing spindle is indeed the causes of the rattle noticed at slow speeds over small bumps when the trans. is not under load.

 

Welcome to TW!

I know TOB issues have been discussed a number of times but, as a fellow 6MT owner, I appreciate you sharing your experience.

 

Thanks for the post. I have that damn rattle when going over bumps with the tranny unloaded. It makes the most noise when pushing in the clutch over a speed bump. Great to hear that you solved it. If I ever have to pull my transmission, I'll remember to change the snout and TOB.

 

I have this rattle too, and under the same conditions you have all mentioned. I hope I don't have to tear into my truck anytime soon though, I only have 50k miles on it.

 

Mine started day one. Day seven I returned to the dealer and got the standard "it's normal" response. Still rattles at 25k.

 

https://www.tacomaworld.com/threads...on-your-6-speed-transmissiom-write-up.338840/

 

I'm so new to board (that was my first post) I don't know how to respond to individual comments, assuming that's possible, so I'll cover all to date here. But first a correction, and one addition to my original post:

Think I said my original TOB was replaced (in process of looking for source of slow speed rattle over bumps) at 50k miles. On second thought it was just prior to my original warranty going to expire. So it was ~ 34k to 35k, not 50k.

Another factor that "may" have something to do with cause of rattle over bumps at low speed, referenced in original post. There is a another noticeable difference between the original equipped TOB and the TOB upgrade/repair kits provided to my by Underdog Racing (UDR). The part of the UDR bearing that rides on the sleeve (it's base) is significantly longer than that of the original equipped TOB. Assuming there is uneven pressure on the TOB as suggested by the scoring/grooving of the aluminum bell housing spindle as I have read and seen on other post regarding why the TOB starts squeaking in the first place. Having a longer TOB base to distribute uneven pressure further along shaft would "seem" to mean less movement by the bearing and less scoring of the shaft. Speculation on my part.

gearcruncher: Have also read about the "constant" problem with the OEM TOB chirps, squeaks, or sequels "anytime" the clutch is disengaged once it starts going out. It's obviously an engineering design problem. I've read it's related to wear/scoring on the "aluminum" bell housing spindle by the "steel" TOB. It literally sounds like the chirping or squeaking of a bearing going out. ...But that is not the "sound" I'm talking about. The "rattle" I refer to is as others described, a totally different sound that takes place over little bumps, rough roads or washboard dirt roads and is most noticeable low speed, but only when the trans is not under load. At least that was my experience. There is absolutely no rattle when stopped or driving over on smooth roads, again when the trans in not under load, trans in neutral clutch out, etc.. Conditions where a bad TOB will still chirp. ...FWIW I really think it also rattles at higher speed as well. Once in the mountains driving by a rock face I noticed the rattle at ~ 45 mph. I happen to be changing gears (trans not under load) on a rough patch of pavement. I can only speculate without the nearby rock wall reflecting the sound back in my lowered windows, wind and road noise cover up the rattle at higher speeds. But at low speed under ~ 25, when not under load it's a metallic rattle. I initially thought, based on the sound, it was a hollow line with a lose bracket that was allowing it to tap back and fourth against a solid piece of metal. ...If that gives you some idea of the sound.

vssman & NM Lance, and others: My initial experience at dealers was "cannot replicate sound". Turns out there were no rough roads around dealer in which to replicate the sound. I found the appropriate road around another dealer and took the service manager out for a drive. Even offered to buy him lunch while we were out (never hurts to be nice to those you want something from). With windows down and doors open I finally got him to "confirm" the noise I was hearing. Toyota probably paid them thousands to try to find the source. They used an attachable recording device (multiple ears) to try and pinpoint the noise source. They replaced the drive shaft mount (or whatever that support boot is called between the trans and rear end that fits around the shaft). They replaced the TOB at less than 36k even though it was not making any sounds suggesting it was bad. There were other things they did but I don't recall. All to no avail.

It was at that point just prior to my 36/36 warranty running out I called Toyota USA Customer Service armed with dealership, service manager names, phone numbers, case number, a list of what had been done, etc.. I told them how much I liked the truck but that I "often" drive down rough roads (hyperbole). I expressed concerns the trans would break and fall out of the truck with the warranty ran out (more hyperbole). That if I have to put up with a rattly truck because the source could not be found I wanted some assurance in case the trans broke about the time the 36/36 warranty runs out. It was at that point he offered the Platinum Extra Care Toyota warranty 8-yr/125k mi). So for several more years I put up with the rattle. It wasn't until recently, at 67k when my TOB started going out, that I actually used the extended warranty. But, having many post about the steel TOB ridding on an aluminum bell housing shaft that I asked the dealer if they would replace the OEM TOB with the Upgrade and Repair TOB kit (oversized bearing and stainless steel shaft that slips over aluminum bell housing spindle. I even gave him the Underdog Racing web site so he could reference the kit. They agreed to install the upgrade and repair kit, and even got Toyota Warranty to agree to deducted the cost of the OEM TOB (~ $116 including tax) that was not used from the cost of the UDR upgrade/repair kits (~ $225). I ete the remainder of the UDR kit. It was after the installation of the TOB upgrade/repair kit that I "quickly" realized the problem of the slow speed rough road rattle had been eliminated. Conclusion? The referenced rough road rattle has "something" to do with the steel OEM TOB, possibly combined with the aluminum bell housing spindle.

Perhaps it was just my good fortune to run across the right Toyota customer service agent, perhaps it's their standard way of taking care of such problems? Regardless, good luck with your problem and I highly suggest looking into replacing any squeaky TOB with an upgrade/repair kit that has the oversized bearing to fit over a stainless shaft that itself fits over the aluminum bell housing spindle. Think I saw on another forum where other companies sell such steel on steel TOB repair kits. Not sure if they all come from same manufacture or not. But I would ask if they have the grease reservoir grooves on the inside of the TOB as the ones I obtained from Underdog Racing had. Just seems like a really good idea to have them.

P.S. ...Ah ha! Just figured out how to respond to individual comments. Solved another problem!

Seriously, will be looking forward to someone with the "slow speed rattle over rough road/bumps" problem to confirm my findings with their own TOB upgrade/repair kit. From what I've read about the TOB squeek problem, you will need one eventually.

 

Is it appropriate to add that I have a MT 3rd gen with a transmission rattle that sounds awfully familiar to OP's?

https://youtu.be/2aCPBaUo5rQ

https://youtu.be/pJjb3zLqAl0

 

My brand new 2019 3rd gen rattles significantly in the same situations. You’d think they’d have implemented a fix by now

From what i’ve read in the 3rd gen forums, everyone’s claiming it’s “normal” - but no one says why. And i’d have a hard time accepting that my brand new truck is “supposed” to rattle like a tin can full of bolts over bumps, without knowing why, and that it’s not harming anything.

I’ve noticed i can hear a similar noise by shaking the shifter back and forth in neutral, while i stand outside of the truck.

If it ends up being the throwout bearing being loose, you’d think that would be a warrantable, defective from factory fix. - my friends got a 2015 w/ the six speed manual, and has never had a rattle. 85k on his now.

Seems some third genners are unaffected as well, which just points all the more to it being a defect.

I’ll try my luck at the dealer, but expect to get nowhere

 

Try tightening the U-bolts on the rear axle. Is yours rattling in neutral?

I chased this down for months, then finally when i lowered my truck and had to install new ubolts that fixed my rattle

 

Let me know how it goes. Mine rattles as much as ever. I've since test driven an 18 DC6MT and it was the the same rattle. However, a A friend of mine with an 18 TRD O/R AC6MT says his doesn't rattle; or can't replicate it.

I've noticed more throwout bearing noises since making videos - on cold days, it sounds like a bad bearing and the part could be unrelated - but it's also getting harder to down shift into 1st gear when moving at all... once things are warmed up it's no problem.

Next service is coming up in a couple of weeks, where I'll bring up the rattle problem, and the new sounds + shifting issue.

 

U-Bolts folks, tighten your rear axle u-bolts. Fixed the rattle in neutral on my 2013 6spd

 

Thanks! They've been replaced, so has both leaf packs, rear cab mounts, transfer case and drive shaft. 2017 still rattles. Watch the 2nd video to hear it - it's 100% in the transmission close to the engine

 

Did the dealer replace the u bolts? I know on 2nd gens, the factory service manual states something like 45 ft/lbs for ubolt torque spec. I think that is a typo because its way low, i think it should be around 75ft/lbs. reason i ask if toyota did that swap is because they torque to 45ft/lbs and the problem of loose ubolts could still be there.

Mine was more of a metallic rattle in neutral. Yours sounds like more of a clatter.

Also, ubolts need to be torqued while weight of the truck is on the ground

 

Mine rattles over bumps in neutral, when moving the shifter back and forth in neutral at a stand-still (only heard with door open) when letting the clutch in or out rapidly at highway speeds or even in the driveway not moving (not shifting, just left in the same gear (heard with window down) it rattles over speedhumps in gear if i’m not gassing it. It /really/ likes to rattle on the one-two shift, i have to baby the clutch pedal to avoid that. I’ll definitely try the ubolt fix after the dealer tells me to shove off
(trying to make sure there’s a good paper trail here, as this truck has a few problems)

It’s a hollow, metallic sound. Almost like the exhaust is banging around or something, but its definitely shifter/clutch related. Probably multiple issues making the same type of noise!

Sounds much like the video linked by the other guy

 

Anyone had issues with a hollow whirling noise from their 6 speed? Mine is doing it in neutral with foor off the clutch. It also does it while driving you can hear it up until 4th then road noise takes over.

 

Update to my Feb. 23, 2017 post, Tacoma 6-Speed Manual Trans. Rattle over Bumps Solved! ...Has been 4-years since that post and an additional 75,000 miles since I installed the Underdog Racing throw-out bearing (TOB) and steel sleeve, still no chirping from the TOB and still no rattle from the transmission area when the drive train is not under load and going over bumps. To say the least I'm very pleased with the Underdog Racing TOB & Steel Sleeve installation.

FWIW, back in 2017 I notified Toyota of the "Rattle Problem" and how it was solved, unfortunately based on forum post I've seen since on newer model Tacoma/6-speeds, they paid absolutely no attention to my notification.

 

I know this is an older thread but...
Proper torque for the factory u-bolts is 52ft/lbs according to the FSM

 

Torqued mine to 75 and havent looked back. I think 52 is low for the only thing holding the axle in the truck. It was 100% the cause of the rattle in my truck