Differential whine/howl, case opened with FTS engineer

Thank you sir.

 

Ok, this problem will soon be fixed! Today, I went into Toyota and had a service tech maintenance manager ride with me to hear the noise (howl at 55 mi/hr when letting off the gas). He confirmed it not to be wind related and promised to get on it. An hour later, he told me the latest: After he called Toyota plant/factory, there is an issue with tolerances with some driveline configurations. They are sending updated new gears in the differential to be swapped out. That should fix our problem. 10 other guys are ahead of me, so a couple of weeks before they get to my truck. Can't wait! Glad they are aware of the problem and fixing it for us.

 

good news, read my post #26.

 

Where are you located? And is there a TSB for this? I hear it on decel at 55-50. Not too worried about it but in the long haul I am

 

I'm located in Moberly, MO. My dealer is at Columbia, MO (Joe Machens Toyota). TSB not ready yet, but they have the parts/fix ready to go. Try what I did (see above) at your dealership and see if you get the same positive results I had.

 

I also get a faint howl/whine at the same speed, but mine is upon decel or no load. Accel always makes it go away.
I've had other vehicles that did something similar, without any issues over time.
I just don't know if it's worth it to have the dealer crack my rear diff open..

@gearcruncher - thoughts?

Any input would be greatly appreciated

Thanks,

Frank

 

Mine is the same although with 6000 miles it seems to be less now.

 

Hey Frank .

Start by checking the fluid . Make sure its at the proper level .
Believe it or not , but when you coast with your foot off the gas , decel is still considered to be a load . This is amplified with Toyota trucks because they turn the injectors off . Essentially , the weight of the truck becomes the load .

 

Just throwing in that I am hearing the same thing. I thought it was normal. Maybe not. Will get it checked out. Mine is a 6 mt

 

That makes sense to me - essentially the rear wheels are applying torque to the rest of the drivetrain when I lift off the gas. This is what you meant by reverse power flow in another thread I gather..
Will do, I'll find the torque spec for the fill plug and crawl under there.

Thanks Gearcruncher,

Frank

 

already been through this same problem...Toyota has a recall/fix for the problem by replacing some differential gears (new tolerances in the sizing). Warranty covered it. Noise went away.

 

Rear diff turned out to be filled properly, no discoloration either. Checked tranny and transfer case while under there - perfect. Front diff will be checked soon as well.

I will be speaking to the service guys at my dealership this week, thanks for the info

Frank

 

Yup. The tech already rode with me and heard the noise. Goes back in Monday to be confirmed by these Toyota engineers that they "flew in". Thanks for the service bulletin #!

 

Fellas, click on my link and you will see quite a bit of info about this from my same issue on my '15

https://www.tacomaworld.com/threads/rearend-whine.407373/

Basically it boiled down to the departure angle of the carrier bearing from it prematurely wearing out caused excess load on the ring/pinion and eventually wore out the edges of the rings causing the wine. New carrier bearing and differential at 8k miles and all is nice and quiet

 

Was it some type of revised carrier bearing? If it was a design flaw, why wouldn't it just wear out in another 8000 miles? The way I understood it on our '16s is that it was a batch of rear diffs in which the ring/pinion were not shimmed(meshed) properly. The noise started in mine around 1500 miles.

 

from what the tech said he noticed my CB might have been installed crooked causing premature wear

 

Makes sense.

 

I'm not sure what to do with mine. I hade the whine at 60 MPhil while letting off the throttle . However after 7000 miles it is gone. Not sure if I should take it in to the dealer or not. If they can't reproduce the sound they won't do shit about it.

 

Mine has the same whine, and I notice it most under very light load. ~7200miles, but was noticeable almost from the beginning. It is easiest to make it happen on downhills or flat areas.

The first tech I took for a ride said he would check the level, which was low initially--along with the tranny--but that didn't solve it (I figured it wouldn't). I then took the lead tech out for a ride, and he confirmed the issue and has ordered me new gears. I have been waiting now for a couple of weeks for them to come in.

 

Dang, mine has the same thing at 50-55 mph. I've noticed if you are going down a hill where you can maintain speed without pressing the gas, it goes away, but as soon as you press the gas again, it comes back...