21 Tacoma still vibrates after TSB.

Hi Bruce.
Nice to meet you sir.

IMHO There are two areas (which I discussed with lots of upper people) and they just smile, that I think aggravates This condition.
#1
Frame.
The frame is way to light.
It flexes and acts as a tuning fork in my opinion.
#2
Driveshaft.
If you remember they got rid of the Double Cardan joint on this gen.
And for some strange reason this vibe started. Duuuuuuu
So people are adding them, or adding single piece shafts.
It’s definitely a large part of it in the drive shaft cause I could feel every single joint pulse on a road test.
Why won’t they address this?
I have no idea.
It was way above my pay grade.
I just pisses me off with all so so called smart people designing this stuff that it takes
The paying public to resolve it.
What ever you do never ever take your rear drive shaft out and drive around in 4wd.
You will be forever be unsatisfied with how it drives..
you will think it’s a completely different vehicle..

 

I can see how you would think that..

 

I am having the same problem. I got my Tacoma back in March and noticed vibration/pulsing when breaking, immediately. I wanted to put some miles on it just to see if it might work itself out because it was a new truck. I finally took it in at about 4K miles. Of course, the tech could not duplicate the problem. This is reasonable I guess because it doesn't happen all the time as mentioned by others.

I recently had a 3/2 lift put in. 6112s up front and 5100s in the rear with add a leaf. (I only wanted a 2 but it came out a 3 in front). Also had the ECGS bushing put in and a diff drop. I plan on taking the truck back in to the dealer...do you think they will balk because I've made these mods and refuse to try and fix the pulsating braking issue?

Thank you to OP and input from others. This info gives some confidence that this issue not isolated.

 

they will, they will find anything excuse to deflect. im fighting with toyota right now for this issue. they are saying my pro does not qualify for this tsb, and the rep from tacoma is not scheduling a test drive bc of COVID restrictions. im really close in selling it. my reason is that althou is a small a insignificant issue, ITS FUDGING ANNOYING!!! every time I drive it ITS VIBRATING like an old truck with warp rotors!!. I love my truck in every other way, except when I brake. I understand if I bought it used, and had a aftermarket set up, but its just a stock PRO.

 

I am in the same boat. Except my vibration starts at 40mph and increases in rapidness the faster you go. Been to the dealer 3 times, on my third set of wheels and tires, had all sets of wheels/tires balanced a total of 13 times, had multiple people and techs ride in my truck and acknowledge the crazy vibration. But, the dealer says it's "normal".

 

Flaco and Ehan, is the frequency of your vibration consistent with tires/wheels, or is it a much faster frequency consistent with driveline? My vibration is much faster, like a driveshaft/driveline would be.

In the near future I will be making a large post about the driveline angles I've measured and research I've done. The angles my truck was built with do not agree with Spicer's installation guidelines regarding a two piece driveline. I am currently looking into moving the tranny mount down/carrier bearing up to correct the angles to be within Spicer's recommendations. I'm waiting for the Field Service Rep to come to town right now to take a drive with me as the local dealer/tech has exhausted their arsenal.

 

Im not sure if its consistent with wheels/tires or driveshaft. I know that when you're at 40mph you feel it start and thats when it shakes the most, almost feels like uneven roads, then as you go faster the vibration gets faster.

 

My 2020 Pro had the vibrations around 25-30 mph. I lifted it with the Icon AAL in the rear (no overload spring) and the Westcott front lift (bottom pre-old collar only, no top spacer) and the vibes went away. Not sure if it was just the AAL or both, but something changed for the better. One should not have to lift their truck to fix this issue, but it did mine.

 

my 2020 had vibrations but my 2021 doesn't. maybe the upgraded rear leafs? the rear suspension on the 2020 felt a lot softer. i also tightened up my u-bolts when i got my '21. didn't do that on my 2020.

 

I'm really disgusted with my new Tacoma. I had the rear spring TSB done in October for the driveline vibration which helped a bit but the vibration is still there, mainly at 25-17MPH while braking but also at many other speeds for short periods of time. Like others on the forum, it's now 3 times back to the dealer, and Toyota Corp is saying all Tacomas have the vibration and they won't fix it, or even try. They offered to buy the truck back (of course they did, with the shortage!) but I don't know what to do.

I'm faced with a dilemma here- live with it, sell it, or fix it. It's obvious Toyota won't stand behind their product. Anyway I owned a HD truck shop for 25 years so driveline vibrations are not new to me, I've fixed more than a few. I took some angles on my Tacoma and did some research I'd like to share with you and ask your collective opinions, so here we go:

I shot the u-joint angles on a level floor sitting on the wheels (I also have a 2 post lift) and shot the angles again on a different day to verify the results. I used two different digital angle finders and an analog finder and got consistent readings so I'm pretty sure about my angles. The front joint is running 3.5 to 3.6° down, the center joint is running .1° to .2° down and the rear joint is running 2.1 to 2.4° up. The reason there's a spread is that it's difficult to split a degree to the tenth and get consistent readings. I shot each angle multiple times to verify accuracy and I cleaned the paint off the yokes I used to make sure I got a good reading. On the tube side I just used the tube as it was consistent no matter where I put the angle finders.


I looked in TIS and could not find Toyota's specs on angles allowed (I'm told they're not in '21 but in '16 or '18 but still haven't found them) but this is a moot point since the Toyota dealer says, "the angles are in spec according to Toyota TIS". It doesn't really matter if they're in Toyota's spec or not, if you ask me. If you have a vibration problem I think it's ridiculous to ignore Spicer's recommendations.

The reason the TSB helped the vibration is the new springs include a 1° pinion shim in them, see the pictures. Toyota knows there is a problem, and they know it's in the angles, or they wouldn't have done this.

I searched the web to find a great Spicer document (there are actually two) on driveline install. You may know this is not a Toyota driveline but a Spicer driveline they've bought. Interestingly, Toyota did not install the shafts according to Spicer's recommendations!

Here's the Spicer bulletin:
https://www.waterousco.com/media/wysiwyg/pdfs/content/J3311-1-DSSP.pdf

You can get it/them from the Spicer website:
http://media.spicerparts.com/media/2


Here's pictures of the pages in question:


Anyway, I'm seeing three problems here:

1. The front joint should be 1° to 1.5° according to Spicer, mine measures 3.5 to 3.6°.
2. The center joint should be no less than 1° according to Spicer, mine measures .1 to .2°. This is probably not part of the vibration but could shorten u-joint life.
3. The transfer case output shaft and diff pinion should be less than .5° or 1° different, mine are about 1.5° apart.

I'm thinking there is a fix for this problem- drop the tranny (actually transfer case) mount about .5" which by my calculations would drop the front joint from 3.5° to about 1.5°. This would also increase the center joint angle by a similar amount. There's an inch clearance between the fan and fan shroud so I think moving the powertrain a bit would be OK. Reshoot the angles after the tranny is lowered and use a pinion shim to get the tranny and pinion parallel. Spicer has a troubleshooting document which basically parallels this and suggests remounting the powertrain to get the angles right. I have good facilities and fab skills so cutting and welding is not an issue. I can remove the tranny mount, shorten it by 1/2" and drop the tranny in a couple of hours without making any irreversible changes to the truck. I've already scoped this out and there's plenty of room by the mount to do this. (I'm actually surprised- I can stick my entire hand in the opening between the case and the mount) I'd actually buy a new trans mount and shorten it, so if it doesn't go well I can just reinstall the original mount.

Any thoughts?

 

Success! Dropping the trans mount 1/2" lowered the front u-joint angle from nearly 4° down to 1° and totally eliminated the vibration! The second joint is now running about 2° or so- this was a quick measurement, I'll report back with exact angles soon. I've put about a thousand miles on it since the modification and no vibration at any speed or in 4wd. I'm really happy about this! There is still plenty of clearance around the fan (to shroud) and I don't see anything else that would be affected negatively. A half inch is really not much in terms of moving the powerplant.

If you have this vibration I'd suggest measuring your angles, especially the front one. Spicer says 1 to 1.5° for this joint, Toyota says up to 3.4° is allowed. Gee, no surprise Tacomas shake......

Step 1: Clamp trans mount to a piece of scrap to keep the location of the mounting pads correct
2: Tack it to the scrap
3: Scratch mark 1/2" to be removed
4: Cut the 1/2" out on both legs
5: Weld back together
Cut loose from the scrap and paint. I bought a new mount in case all did not go well, I could put the new mount in to restore the trans back to factory spec but that doesn't look like it will be needed. Picture is the new mount and the modified mount next to each other showing the mount is now about 1/2" shorter. Mine is 4wd, I think this setup is the same on all V6 4wd trucks from 2016 to present. If you have a 2wd, your trans mount is a "V" shaped thing that will be a bit different to modify.

Replacing the mount was easy but one end of the crossmember had to be loosened to get the mount out. Total time invested was about an hour and a half. I did take a ton of pictures and shot a bunch of video, that took much longer than the actual repair did.

If anyone wants the video PM me and I'll link it to you. I probably won't post it on YouTube.

Good luck, guys!

 

The trans drop is a good idea but I can't see how it would fix a brake vibration. Obviously when the rear brakes engage the rear axle will tilt which can cause the u-joints to bind, but there should be barely any movement up near the TC where the drive shaft connects due to the carrier bearing. So in theory the truck would vibrate all the time if the DS angle was constantly at too steep of an angle. My 3rd gen only vibrates while braking at low speed and the dealer has not been able to fix it. I get the same "they all do it" from my dealer. Same thing with my 2nd gen but it happens while taking off. Truck has a quick little giggle feeling when first taking off. Not breaking you balls here just generally curious as I would like to find a solution for both trucks.

 

It sounds exactly like mine- the vibration was most pronounced under light braking from 25-17mph but could also be felt at a constant 23mph on a super smooth road. It would also vibrate at random other speeds, like as I accelerated onto a hiway like 48-50 or something very quickly. Once I got acquainted to the vibration I'd feel it occasionally at other random speeds too. I can't explain the physics of why this is so, but once I measured the angles of the joints and compared them to the Spicer specs it was clear what needed to be done.

Assuming yours is the same shake as mine, I wouldn't call it a "brake vibration", it's much too fast in frequency for it to be brake.

 

I have been chasing a rattle/vibration I hear in the truck during braking. Seems in the 30mph and lower as we approach a stop I hear stuff rattling/vibrating. Dropped the rear seat thinking something was not secured. Is this what you are describing above? Sorry just saw this and read the comment on braking vibration.

been driving us nuts.

 

why haven't the fixed this on the 2021s? they rather you come back for the TSB? fucking stupid. and why didn't they include the steering wheel damper with the truck?

 

CRX: Yes, it could be. Toyota knows about this problem and has a TSB on it (see above). Driveshaft vibrations are very fast in frequency, much quicker than your typical warped drum/rotor or tire issue. Take yours back to the dealer and see if the TSB applies- it should. If you're not mechanically inclined find an independent tech to verify the driveline shake, it should be nothing more than a short road test.

Mine would be felt mostly in the steering wheel, but also rattle the dash sometimes and be felt in the seat and floor. Mostly from the driver's seat, much less from the passenger seat due to being felt in the sw.

Crypto: Who knows. Also, why do they change the rear springs to add a pinion shim when the real fix is changing the front u-joint angle? Big money to change springs, much cheaper to change the mount......

 

I don’t feel it in the steering wheel just hear the rattling in the back of the cab during braking.

thanks

 

@Dual Port good on you for doing that fab work and trying to resolve the issue on your own. Glad it worked! Super disappointing and unacceptably ridiculous that anything like that is needed to make a brand new truck drive smoothly. Toyota needs to at least pretend to give a shit about the end user experience. But I see this garbage in my industry also. We occasionally will deliver a brand new ~$15k hot tub that leaks so badly it won't hold water. Then we get to remove it before it even gets used once by the customer and fix a brand new product that was built with defects. Pisses me off, because it's avoidable. Manufacturers need to personally feel the sting of their shortcomings and stop hiding behind the dealers.

 

Does this apply only to 4x4's?

 

I'm sure it can also apply to 2wd. All trucks have driveshafts, so all can have driveshaft vibrations. If you have a driveline vibration, get a digital angle finder and see where your joints are running, especially the front joint. My guess is it can easily be the same problem.