Howl from rear differential

On my 22 Tacoma Trd 4x4 I noticed that is is making a howl that is most noticeable at 50 to 60 mph and coasting at light to no throttle. The whine / howl is coming from the rear end and something that I find annoying. Do Tacoma's have problems with the rear end / differentials.

 

Yes, it’s common. Mine has a faint whine about the same speeds. I didn’t want the dealer playing swap-a-part with it, as the OE unit will be more reliable in my opinion.

 

There have been hundreds of cases. The noise is a resonance caused by harmonics between the diff, axle housing, springs.
Funny thing is not many, but some, do it. Toyota has a TSB that helps insulate the cab from the resonance noise.

 

I kind of like the howl noise. Couldn't say why I do, just do. kicks in for just a moment when accelerating between approx 45-60 ish.

 

This is a feature known as "audible coasting speed indicator".

 

Another thing for you to consider:
Is the Diff full of oil?

Mine was 3/4 Qt low from the factory.

It's easy to check. Just remove the Fill Plug (if I remember correctly, a 15/16" socket fits perfectly), stick your little finger in the hole, and if you don't get oil on your finger then it is low and needs oil.
Takes 5 minutes to check.

 

We need more people buying 4th gens so we can cut back on the duplicate 3rd gen threads

 

You know they will post 4th gen things in 3rd gen forum. You know they will.

 

My '06 TRD OR had a faint whine (would not call it a howl) for 15 years and 127K miles. My '21 has a similar whine, albeit a bit fainter, for 25K miles and 2+ years. IMHO it's normal and not worth getting your panties in a bunch.

 

Mine has a faint howl at the same speeds. No different than any other truck I've been in or driven. Kind of a soothing sound to be honest lol.

 

I can't wait for the 4th gen threads to rev up so I can be like the douchebag 2nd gen guys and shit all over in them...

 

In all seriousness, my 06 T4R and my 22 TRD OR sound exactly the same between 45-50 MPH. Same whine. Not before 45, not after 50. Same, same.

 

Hey, so I know that I have one of the most reliable vehicles on the planet and recognize how fortunate I am that I may drive this for 100k with only oil changes and possibly a set of front pads. Its just that I have not had a vehicle with the classic "Pinion gear / ring gear" whine for many a simi-century. My guess is that is it maybe caused by the contact pattern, (pinion too deep / or too shallow).

With that being said, I did crawl under the truck to check the backlash by grabbing the drive shaft and moving it back and forth. I also compared it to the exact same truck that is a 23 year. They both were the same backlash so that does not seem to be an issue. So not to get my knickers bunched up I guess I will just reminisce of the time I drove a international harvester pickup from the early 50's while in college and enjoy the ride.

 

I wonder if this is a reason so many advocate going 80 and hammer the skinny pedal to get there.

 

That has been a popular hypothesis and tested many times over. It ain't it.

If you search 'diff howl' you can read threads on this for weeks and weeks.

Here's one of my favs: https://www.tacomaworld.com/threads/rear-diff-howl-update.798383/

And the big one: https://www.tacomaworld.com/threads...oise-howling-when-feathering-throttle.442341/

Many have conned a dealer into replacing their diff, only to end up with the same thing. Many have re-geared with aftermarket gears using a quality shop, only to end up with the same thing. Some have made non-diff related mods and had it improve or go away. It's a nuanced issue.

 

My 06 T4R has had 2 gas caps, oil, 1 battery, and tires changed up to 150k. Since then, I changed wheel bearings (hub assemblies just to be safe), battery, and new brakes. That is it. Absolutely problem free for 180k miles.

 

Release of the 4G has been delayed until Toyota engineers get the diff howl properly tuned to the desired note.

 

https://www.youtube.com/watch?v=RVNjq_gRFLE

 

Sage advice, the motto of our group of Alpine downhill skiers was "tuck it and you will make it" . I also want to thank the OPEC nations for their generous supply to allow for the massive consumption at recommended "80 Mph"

 

Just got my 23 OR 300 miles ago. Did the whine on the drive home from the dealership. It's now gone away. Thank you Jesus

Timo23OR