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

I guess everyone on here got theirs fixed by some miracle.

 

Finally found a good dealer willing to help. Got mine done last summer and the howl has not returned in any way after the TSB work they did. Also resolved my atrociously loud HPFP and 7 months later the screeching squirrel sound has not returned either!

 

So the TSB has them replace what parts?
Leaf springs? Or did they replace parts in the rear axle?
My 18 is getting louder and does not fall under the TSB from memory.

 

I have learned to brake real hard and fast from 61 to 55. That helps keep the howling to a minimum for me. I now have a slightly weeping rear diff that is going in Friday (one year service as well). Hoping they at least check the torque on the bolts, but I will probably be told no seeping was found haha May see if i can push them some more now that gear oil is starting to show. Weeping diff and the howl. Maybe it will get Toyota to do something?

 

New rear differential for me.....

 

Stay on them, my friend.

 

Nope...the conclusion is that it a resonance through the springs/mounts. The TSB doesn't appear to apply to Access Cabs, and many that have had it done say it doesn't work.

Mine hasn't gotten any louder since 3K miles and it's not a reliability issue. I don't really want some knuckle draggers ripping out my interior and breaking a bunch of clips and who knows what else anyway. So for me it doesn't bother me and I have forgotten its there for the most part. I checked the level of fluid (actually changed it at 30K) just to make sure nothing obvious was up...then forgot about it.

 

I'm convinced the problem is in the differential itself. A slight bit of "play" in the gears themselves causing a vibration ("howl").

The TSB doesn't do anything to affect the source of the problem. It attempts to minimize the transfer of vibrations to the truck body; thereby lessening the perception of the vibration in the cab.

So the success of the tsb is dependent on how bad the vibration in the differential is to begin with.

Just speculation on my end.

 

I’d agree and I had the shavings in my rear differential to prove it, at least for my truck. My pinion angle was off and gears were ground. The bottom line is, yes, this is a resonance, but it’s the result of a differential that’s making more noise than it should. It’s doing that for a reason. Why else would almost everyone’s be ok when new and then get noisy when it got some miles on it? Something is not working and or wearing right. I don’t know but do know I had a quiet diff when new, then a noisy diff and then a quietdiff when replaced. If it gets noisy again then I’ll chalk it up to something being wrong with the setup and I’ll move on.

 

So, when they installed the new diff, did they also adjust/correct the pinion angle?

If the pinion angle was off and not corrected (and was, in fact, the sole "defect"), I might expect the same thing to happen to the new diff that happened to the old.

This will be interesting to follow. After how many miles did the howl show up on the first diff?

 

On the first diff it started around 1000 miles. I’m around halfway to that now post differential replacement. Time will tell.

 

If pinion angle wasn't changed with the new diff, one might expect the new diff to wear incorrectly like the old one and re-introduce the "howl".

 

I’m hoping it’s ok but I did pick up my truck with a new “shuddering” throughout the speed range so back to the shop it goes....

 

Man, if its not one thing its another. Sorry to hear! Can you describe this shudder in more detail? Does it feel like its engine or rear diff related?

 

It doesn’t feel like the rear diff at all. I’d say “surging” but don’t want to get in a debate with some over what constitutes a surge. Lol. Seriously, it’s jerking back and forth when accelerating and it’s bad, not just a little. Could it be loose leafs since they put new ones in? Or, could it be something from pulling the tranny when they did the repair last time? I am at a loss and this is the busiest time of the year for my job so just getting this thing back to the shop is not going to be easy.

 

The dealer performed TSB 0013-18-NOISY on my 2017 Taco. It reduce the noise by 70-80% but did not eliminate it.

 

My 2019 Sport has this noise FWIW. Have not taken in yet to document.

 

You should take a look at your rear cab mounts and let us know if it came from the factory with the TSB. Curious if they added that or not.

Edit: yes, get it documented please. The more the better.

 

I simply can not believe they're still sending out trucks that have this problem. And are still giving people the run around.

 

Could someone with a 2019 OR post up a pick of their cab mounts?