3rd Gen Poll: Rear End Noise howling when feathering throttle

G'day all,
Once again, this is a great thread when it stays on topic. I have read this entire threat several time because I'm on the "list" for a 2018 Pro and I'm highly concerned about this condition. But, the way things are going it may be 2019 before I get it. But I digress.

This rear diff whine/howl has been diagnosed as a differential vibration (resonance) condition transferring sound through the chassis and body, per T-SB-0018-18.

One part of me it thrilled with that conclusion, cause it strongly suggests it is not a mechanical (Toyota Engineering) problem as some suggested/believed. The other part of me finds it hard to believe the resonance was not detected during the Toyota testing process prior to release. But that just my opinion and I have nothing to back that up.

Again, reading through the T-SB, I can see the efforts for dampening in figure 7, but gotta wonder what is so different about the new rear springs.

Can anyone shed some specific light on how the new springs differ from the OEMs?

Thanks

 

New leaf packs have a shim that changes the angle they sit at, same for the decel vibe tsb. Might not be present at new due to settling and/or wear of cab mounts etc. Toyota, like all companies, may have known and weighed its options. Hold back production or be first to market for a problem most won't notice.

 

I believe the TRD DCSBs get new leafs and and the TRD DCLBs do not. I could be reading the TSB wrong though (Long vs Super Long). I’m not sure what the difference in the leaf packs are between the two.

Like EdgeCrusher said, it’s problem a shim change or something similar. Not every Tacoma has the howl so it’s probably easier/cheaper to take care of it on the few later down the road.

 

my 2017 DCLB Trd off-road unfortunately developed this infamous rear diff howl around 55mph 2weeks ago although very faint sounds like tires humming . Just came back from the dealerships 5000 miles service and I was informed that there's this T-SB-0013-18 and they're ordering the parts . Anyway my plan is if that doesn't work then I'll just upgrade tires to KO2 bro or duratrac

 

Keep us updated after the TSB is applied to see if it solves the issue.

 

Have an appointment for next Wednesday. When I called to set up an appointment the dealer/service shop didn't want to commit to the TSB.

Which I get. They need to diagnose the noise (...again), and then get permission/subsidy from Toyota to do the fix.

My problem is I live about 60 miles (a little over an hour) from this dealer and it's the closest. So my fear is after they diagnose it (again) they ask me to come back again on another day. Which would be a huge hassle and time commitment; considering its already been looked at by a FTS.

So I just called and left a message with the regional Toyota case manager who has my "rear end howl" case to see if she'll just push the parts to the dealer for me.

Worth a shot I think.

 

That sounds like a good idea, hopefully it works so you can bypass the nonsense at the Dealer level.

 

I went by the dealership last week when this TSB came out. I wanted them to go ahead and order the parts since the problem with my truck is well documented.

They haven't ordered the parts yet because nobody there or at corporate knows what exactly the BD22 differential is. Without knowing that, nobody will commit to ordering the parts and approving the repair.

That blows my mind.

 

OMG

 

The Night someone first posted the TSB I searched around on the Web and best I can tell is the BD22 is the 8.75 Rears.

 

Somebody knows.

 

I think you mis-interpretted my post there. I had this issue, with many more, since verrrrry early on. My howl issue was the bane of my existence and ultimately the reason I dumped the truck. It was pretty clear that it was a resonance issue for a while, but Toyota was replacing diffs until just very recently because of the issue. There was no definitive evidence, from Toyota, that it wasn't a long term failure issue until this TSB.

TBH this TSB is the first actual acknowledgment that its not " a normal characteristic of the vehicle" or more accurately--the first acknowledgement that its something that should be fixed.

I'm happy for you guys. I hope it works better than the rumble strip, transmission clunk, and squeaky leaf TSBs did for me.

 

I agree. All the evidence points to that, but how they can use such vague terminology in the TSB that nobody at any level of the company can interpret it is just laughable.

Would it have been that hard to just reference the 8.75" rear? You can't misinterpret that.

 

Agree with this. My door jam references an 8” diff with a 3.91 gear ratio (B06A)...I have a 6MT TRDSport (8.75” diff and 4.30 ratio). Meaning everything about my diff code is wrong. Toyota has some f***ed up shit going on with their QC in that sense.

I won’t be going in for service for a few more months but I hope they cover mine under the TSB as they should.

OA

 

https://www.tfltruck.com/wp-content/uploads/2015/08/2016-toyota-Tacoma-Technical-specs.pdf

See page 30

 

Yeah. Took me all of 5 secs....bd22a and bd22an. There goes the tsb is a scam argument.....

FWIW I listened to my co-workers truck. Had the tsb done at Toyota of Walnut Creek. Dropped the truck off at 8 am on saturday and picked it up at the end of the day.

No howl. Oh the humanity.....

 

That's awesome to hear that the Howl is gone on his Truck, sounds like he has a great Dealer to work with too as they ordered the new springs and everything prior to his Saturday appointment!

 

http://www.fourwheeler.com/vehicle-reviews/1508-a-look-at-the-all-new-2016-toyota-tacoma/

 

Did he happen to say how loud and what range of MPH his howl was before the TSB? For example, mine howls over an 8mph range and takes HD radio 30+ to drown it out (very scientific I know ha). Trying to get an idea of how bad his was. If his was as like mine and now is completely gone then I am STOKED!!

 

I'm fairly deaf....and I had to teach him to listen to his howl.....so to me it's pretty faint. So was mine. I don't know the exact range.

I took it for a run on the highway for about 25 minutes through a range of highway speeds and throttle applications.