21 Tacoma still vibrates after TSB.

There is a 1° pinion shim built into the new springs, see my post #50 and pics above. It's their way of compensating for a driveline angle problem, and a really expensive way to add a pinion shim. Measure your angles first, I wasted 40 hours taking it to the dealer 3x and it took me a couple of hours to fix it myself.

 

Thanks for the heads up. I will check my angles and take care of this myself.

 

How certain are we that the TSB shim is 1 degree? I'm thinking about skipping the TSB and just installing a 0.5 or 1 degree shim myself along with new shocks (because I don't like the ride) set at stock height. Did you take your TSB shim out and was it labeled 1 degree?

 

Old thread I know but it has some of the best info on this topic. Since you've done a lot of these TSBs yourself, knowing shims often just move the speed at which the vibe happens (I've experienced this myself), would you suggest doing a 1-piece driveshaft, double cardan joint, push the truck off a cliff?!

 

Good Morning.
Dam..
I hate questions like this cause results are not guaranteed and, going after it is expensive.
I think I read somewhere that Tom Woods is not making one piece shafts for the Tacoma’s because
of complaints etc. If this is true, what does that tell you? It doesn’t always work.
Double cardan joint was on a gen one. No vibes per se.
But, gen one.
Since I’m retired, I can talk about stuff more openly.
I had a chance to have a heart to heart with one of the factory reps.
And while doing one of these tsb’s to add it to the applicable years (You’re welcome
2019) I said these frames are to thin, setting up a secondary oscillation and, you can’t isolate
It. His response was, “You’re not wrong”. Mmmmmmmmmmm…

Myself, if I was going to chase this, I’d try to phone a friend with a one piece and see if you could swap
shafts for a afternoon.

Would a double cardan joint on the 2 piece help? Don’t know
Would a double cardan joint on the 1 piece help? Don’t know
Every truck and customer is different and that’s what was so frustrating.
What ever you do, I would not use your original shaft to do anything.
Find a donor shaft for the ends.
That’s all I got…

 

That's a great post and thanks for taking the time. You sure know this topic and have the experience with it. What you say about the resonance also makes sense and my truck does this and seems to be somewhat tied to the pavement quality. I like the suggestion to give a one-piece a trail run. Too bad I don't have access to one. I'd need a very generous forum member to help me out!

We've also been discussing in other threads that Toyota's driveline tolerances in the TSB and on the trucks, are out of spec with the Spicer design manual. There's good screenshots in the thread linked below. Per Spicer, being out of spec with the numbers we have, will certainly result in vibration. The main culprit that cannot easily be adjusted is the t-case output to the front driveshaft angle. Two members in the thread cut and re-welded their t-case mount, took measurements, then shimmed the rear as needed and were able to get all joints within Spicer specs and have vibration-free trucks. Modding that mount isn't really that hard and is cheaper/easier than getting a 1-piece driveshaft but I worry, what else in the engine/tranny/t-case might not like being tilted downward in the rear by 1/2"? Could this cause other problems? If it's pretty risk-free, I'd be more inclined to try that next than the 1-piece driveshaft.

https://www.tacomaworld.com/threads/21-tacoma-still-vibrates-after-tsb.740185/page-3

 

1/2” won’t bother.
Like I said before, I would use a different mount to play with and keep your stock one if you had to go back.
More than .5° and less than 3.0° is kinda the area your looking for.

Within 1° of each other if poss.

IIRC

just check clearances on the fan shrouds and firewall etc

 

Well then, perhaps it's time to order up a mount and cut that puppy! I could get that done and painted in under an hour. Worth a try if there's no risk.

I've also sometimes wondered about mods that stiffen up the rear of the truck and/or add weight. Like I never hear this complaint from people with camper shells. I don't really like or want a shell but some form of off-road rack might firms things up, with the bed mostly, and not the frame but still. I just wonder if it'd help if resonance back there is part of the problem.

 

Car companies have regularly hung weights off body mounts, exhaust, etc to dampen a certain frequency.
Yes weight firms things up.
Go through your angles before and after the mod.
And of course you do it with the suspension loaded..
Keep them for future reference.

 

I just tested the truck again tonight with the 1/2 degree shims, full tank of fuel and my KTM (~230 lbs) in the back and all the vibes went away except right at 53 MPH and only while coasting downhill (I live in the mountains). That said, I'm feeling better about the truck know. I will likely try some 1 degree shims next and see what that gets me. I forgot to measure the angle change with the weight in the bed this time but before the shims, the weight would change my pinion angle 0.25-0.5 degrees vs with no weight in the bed. If the 1 degree shim doesn't duplicate the "weight in the bed" results then maybe the modified/welded t-case drop is next and last resort, I can put a camper shell or some kind of off-road rack on it as I know for sure the 250 lbs combined with the 1/2 degree shims does the trick.

I also have the Bilstein 5100s on the shelf that I was holding off installing as I like to resolve one issue at a time. Maybe I'll toss only the rears on and see if they manage the vibes differently than the stock shocks.

 

Any idea why a TSB was never issued for the 6M? This vibration issue was noticeable to me the day I took delivery of my '20. I was coming from a '04 2wd manual Gen 1 that never had any vibration issues. I immediately took it back to the dealer and they sent me a video of the tech going through re-tightening all the suspension fasteners and wrote it off as vibration caused by off-road tires (DuraTracs). When I installed my DB it changed slightly but didn't go away.

 

Not sure why the MT is excluded. Your dealer should have at least followed the troubleshooting steps in the TSB. And tires yep, I kept my stock wheels/tires around just for this reason. Lame dealers.

 

I have a '21 Taco Access Cab. I had the TSB done for this problem as well and it didn't solve the problem.

 

Hmm would you say the long bed helps reduce the effect of the driveline angle? Or pretty negligible..

I ended up swapping leaf springs, and went to a single piece driveshaft and it greatly helped. Still pops up under braking but only at very intermittent times depending on the severity of the braking.

 

If under braking, it could be the rear brakes. Try stopping with just the ebrake. My brand new truck had defective rear drums and the dealer replaced them. Ultimately, the driveline issue was never resolved after two years, countless hours reading on here, trips to the dealer and some shim experiments myself. I got tired of thinking about it and sold the truck yesterday and am moving on. My son also just hit 6'3" at 16 years old so the Tacoma's days were numbered anyways. Good luck guys. I can say I'm pretty damn happy not thinking about this anymore!

 

So sorry. Late on this. My 2023 SR5 DC 4x4 has these issues. I have little over 2300 miles on it.

? Did Spicer make all the drive shafts for Tacomas gen 3 ?

I know my dealer is going to try to blow smoke up my ass on this TSB.
My 2006 have several most fix the issue. But many on here are saying this current TSB doesn’t fix the problem.
Accept it do nothing or Do TSB

Why don’t the just fix the angles instead putting vibration dampners in the steering wheel and springs.

 

Yes, and there is a Spicer sticker stuck to the rear driveshaft stating it is a balanced assembly.

 

Some of these vibrations everyone are feeling are simply the engine and transmission. I feel the engine vibes on acceleration from my truck in the steering wheel and gas pedal. I’ve owned 5 3rd gens. Each and every one have multiple quirks some alike some not. It’s kinda a crap shoot. I haven’t owned one yet that didn’t have something different from the next one that I didn’t find annoying or unacceptable . Just the way it is

 

Yep, it is "just the way it is" as you say so, I sold mine. Pretty bummed since I always wanted a cool Tacoma but eventually gave up on the dream. My son also got to be too tall for the rear seats so it was inevitable anyways. Now I'm looking for what to replace it with. I'd prefer a Toyota still as I love how they retain value. I almost bought a new 4Runner last week but after searching online, read they're prone to steering wheel vibration. I drove two, one used that was perfect with no vibes but it was not the color I wanted. I went back to the dealer and we pulled the only new white one they had (what I wanted), literally out of the showroom, and took it for a drive. Sure as shit, it vibrated right where the forum and reddit users said it would, around 60-65 MPH. The dealer then claimed they'd fix it. I told them no way in hell I'm rolling off that lot with something that "needs to be fixed" as they also refused/couldn't to fix my last two Tacomas! Now I'm trying to determine if the GX460 has any of these vibes. So far from what I've read, they don't. But, crap MPG and limited approach angles need to be accepted or dealt with.....

 

Side note for anyone still reading this thread, when I did install 1 degree shims, it removed the 30-10 MPH vibe. The dealer refused to do this TSB for me so I did it myself. I was still left with a harmonic vibe around 50 MPH but that could have been my AT tires being worn oddly. I sold the truck before having a chance to confirm that though.