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

My original and new both howl

 

Turns out that there are a bunch of us that have had a diff replacement to no avail..... we should start a club!

 

I was a hobby shade tree mechanic (not a technician) for over 40 years and managed to keep my cars and motorcycles running in top form. The first thing I would look at is proper pinion/ring gear backlash. Improper backlash or pinion/ring gear engagement will give you a howling noise. A bad bearing, improper shimming or worn gears will cause this problem.

Has anyone been stranded on the side of the road because of a differential issue?

 

I agree, Toyota should take care of this. The service department at the dealership where I purchased my Tacoma has a good reputation. I had not realized I purchased the first year run after changes were made to the Tacoma. If I require warranty work and am able to learn a viable solution to the problem from a fellow gear head, I will share it.

 

Mine's quiet at 7200 miles. I have not towed with it yet and did top off the diff with Mobil 1 at 5k

 

I can definitely get mine to make the noise. Sounds similar to the control arm whistle, but can obviously be manipulated with throttle. Will bring it up on my 5k service tomorrow.

I don't think it's too bad. It's definitely within the range of normal 4x4 quirks. This is still the tamest/ quietest 4x4 pickup I've ever owned or driven over the last 30 years.

 

It should have nothing to do with 4x4, the rear diff is the rear diff

 

Using the term 4x4 loosely here. I understand what a differential is.

Just making the point that this is imho an idiosyncrasy and not a big deal. I guess time will tell.

 

My Tacoma TRD Off Road is new and only has 350 miles on the odometer. The loudest noise I hear is the exhaust and I thought I heard a slight whistle when I took my foot off the accelerator at 45 mph. Are we certain it's the differential making the noise and not the drive shaft or transmission?

 

Well the dealer notes on my rear diff replacement for these exact symptoms said "premature wear" and "failure"

 

Yes dealer on mine used Bluetooth chassis ears then a stethoscope to isolate to rear diff on Lift before replacement

 

Yes, Started at 3k miles. DCSB OR 4/16. Not super loud yet but getting worse.

 

Any chance the problem is caused by soft pinion bearings?

 

I heard another theory it would be Carrier bearings

 

That's my hunch too

 

Same here. TRD OR 4x4

Not sure of the build date but I can update later.

It started early on or maybe it was always there and I just noticed once I became more in tune with the truck. It got worse over time, and I had it replaced. The replacement diff still howls under the same conditions, but it is nowhere near what it was. Keeping a close eye (ear) on it.

On my last visit, I made sure to have the manager ride with me and acknowledge on the writeup that the noise is still there, and that the truck is not modified. Same as the braking shudder. So when I get tires/wheels/maybe lift, they cannot blame the parts or the mods. I think I am still going to hold off on any mods simply due to these issues.

 

I'm thinking rough cut gears and not enough preload on the carrier bearings.

 

Have you noticed it on your truck? I know we took delivery within the same week and our trucks are the Texas twins. Just noticed this recently on mine. I have about 5K miles.

 

Yep mine has it. Parts are on order.

 

replacing the rear diff?