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

The problem is that Toyota has not identified the exact source of the whine in the diff, and why it makes that noise. It shouldn't. Bad design? Parts manufactured out of tolerance?

 

It functions though. 2nd gens have pretty much the same axle. The 3.90g axles with the Locker have 8.75 inch axles. Only thing different I can think of? Someone call me out please, I may be wrong.

 

@smitty99 did you get your diff fixed/resolved? Haven't been on TW in awhile.

 

I have a manual with the 4.30 with the whine. I have no worries on reliability, but it isn't right for a brand new truck. The above observation (More complaints with the TRD OR) got me thinking....from reading other posts, the new 4.30 manual and the 3.90 in the TRD OR are supposedly the new 8.75" rear end. If that is true, it means that its an unproven rear end, and could indeed have a design flaw.

I will be letting my dealer know about this at the 5K service, as I want the complaint in my service records and hopefully they report it to Toyota (more complaints = more likely to address). I'm not going to worry too much until they come up with a fix. My larger complaint is the cyclic vibration at 55-65 mph. I thought it might be the common front drivers side needle bearing at the differential, but engaging 4wd does not cure it totally.

 

8.75- I stand corrected. It wont cure it, but my friend got the ECGS bushing and had it swapped out. Drives with no driver's vibration-zero!

 

They probably don't care. This is complete speculation but if the differentials going back are being found to have no issues or excess wear then they aren't going to spend a bunch of money trying to make the differential quiet. This especially won't happen if the differential is a part that is contracted out (I could have sworn at one point I saw GKN as the contracted company).

It takes a lot of money to R&D a new differential, especially if the sole purpose is to just make it quieter. More than likely they will spend their efforts elsewhere making the cab quieter as that will be seen as an improvement by people that don't have or hear this issue as well.

We will see, but either way my new differential howls and hasn't gotten any louder or changed in any way since the day it was installed. Have about 5k miles on the new diff.

 

This is exactly what they are doing.....sound abatement is in work, not fixing the whine.

 

No still waiting for TSB

 

Went for the drive today, master tech heard the noise. They took the truck for the rest of the day to put the chassisEARS on it.

Ill let the tech no I just wanted it documented, he was a nice guy. I will let you know what I find, I doubt it will be any thing that hasn't been discussed in 90 pages.

In all honesty, as long as the dealership documents it - I really don't care. Just don't want Toyota coming back and telling me the shell, lift, tires i plan on adding caused the noise. I don't know if the vehicle industry uses dMFEA for design, but if they do I would assume the differential is a severity 3 or so issue. So all tests likely included a 95/95 interval- good enough for me.

 

I'm sure they have their version just like I'm sure they have sixsigma black belts that make every meeting longer than it needs to be.. but rear diff issue would not be an SII not SIII.. so it would be a (p)C(s)II(d)4... that is assuming it is a "fault" to begin with - your application of FMEA equates detectable sound with a failure. Sounds like Toyota engineering has taken apart symptomatic examples and subsequently kicked the issue over to the Noise/Vibration/Harshness NVH or equivalent team to address.

 

They need to waste our time so they can save us some later. Job Security really.

Makes sense, design failure mode likely poor tolerance stack or equivalent or process failure mode poor backlash setting. could even be S1 "User inconvenience" or however they word it.

... they seem to be doing an excellent job, I bet they are all black belts.

 

Just heard back, they could not track it to the diff. Suggested it was a tire noise. Oh well, its documented.

 

Are they still using six sigma ? My gawd ,I thought that went out with Neutron Jack Welch from GE in 2001 .
One piece flow and continuous improvement from Toyota were the rage in the US in what , 2003 till ?
The classes on the latter two were fun !

 

...Currently. Believe it or not people are still poke yokeing around with like chickens with their heads cut off.


Sigh.

 

Did you put aftermarket tires on?

 

No everything is bone stock. I asked to schedule an appointment for next week to pull the tires and balance them. He stated that this was not necessary as the problem would need to get worse before we can fix it.


I had them correct the tech description saying noise is still present after listening.

I guess I succeeded in getting it documented. ..

 

Good I'm glad you didn't do any aftermarket mods, because once you do this it will always be their first excuse.

 

https://youtu.be/_UMazkIyBK0

 

Hello All:

My first post, my first Tacoma. 2016 MT Inferno Sport AC w/Tow Pkg bought 08/16. I'll get to the intro stuff later... Hi.

I have 35+ years in the VW camp, mostly Diesels. I am well versed with pain. I still love them despite all the bloody knuckles.

Thanks to this forum, I performed "maintenance" at 512 miles with full approval from "Service Manager". His blessing? "If you do in right, NO warranty issues". Easy vehicle to work on thus far.

Engine: TGMO 0W/20 and filter - OEM
F/R Diffs: Red Line 75W/85 GL-5 - New washers - OEM - Torqued to Spec via TIS
MT/Xfer case: Redline MT-90 GL-4- New Washers - OEM - Torqued to Spec via TIS
All Drive Shaft Zerks: Spicer Ultra Premium Synthetic Grease® - Grease needle is key on the front shaft points!

Prior to all this damned BS "maintenance" on a NEW vehicle, I could hear the slight rear diff "howl" on slight deceleration at around 55-60. It is gone now.

The RPM "hang" during shifting is gone as well. Damn, it actually behaves as a manual transmission should!

The Zerks took several pumps (

$54 Lincoln 1134 Pistol Grip Grease Gun with 18" Whip Flex Hose and Coupler, 6" Rigid Extension, 7500 PSI, Premium Dual Lip Follower, Variable Stroke, Jam-Proof Toggle, Filler Air Bleeder Combo

Lincoln 1134) to fill/purge the cross/voids of whatever lube was present. Looked like Moly paste... Especially the rears post transfer case. Fronts oozed "reddish".

I took an albeit tardy "preemptive strike" to do what I can... Still SAD that I had to finish the process to hope to have a fine and long lasting vehicle.

If I heard the "whine" heard on smitty99's vid, I'd be rather unhappy. That is CRAZY. Good Luck to smitty99.

 

looks like someone has a case of tacomaworld paranoia. Want to send me all those new fluids you discarded?