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

Is it bad to run 85-140 on the stock diff? I live somewhere its 80 degrees + year round so I wonder if the thickness would be fine.

 

I plan on changing mine out here soon. Will probably go with a 75w-140 Redline.

One of the reviewers claims his howling went away (different vehicle though).

https://www.summitracing.com/parts/red-57914

I figure it's worth trying. Desperate times call for desperate measures lol

 

As long as it's GL-5 rated, you should be fine.

 

No, but it is thicker and the Lucas stuff is non synthetic so you would want to change it every 15k

 

There's nothing new or novel or special in these diffs that require anything specific. GL-5 and you're good. Far as I've heard aftermarket gears guys recommend 75w-140. My best guess is the 75w-85 spec is based on chasing bits of drag for fuel consumption reasons.

I only worry about specific fluids in the tcase and transmission in these trucks due to syncros.

 

Lower your tire pressure? Makes a big difference.

 

Staying to wonder if if the difference is some guys having dog ears.

 

Watch the video in post 5992 and turn up the volume. That’s a mild case and one of the lower pitched sounds.

 

... and then imagine driving your truck 200 miles like that.

 

My truck makes no noise - especially anything like that.

 

You've got some mods on your truck though, plus sport trim (different diff), manual transmission, and access cab. All of those may be the reason.

 

That video is perfect just listening to it makes the hair on my neck stand up. I don’t give a shit if it’s not a safety issue... Toyota needs to man up and fix this Horrible quality control problem or go after Hino for a fix.

I suspect Hino contracted Toyota into so many years of using the DB22 differential, Toyota neglected their due diligence of ensuring it was a quality product and now we’re all stuck with this piece of shit differential and it’s horrible harmonic whine that Toyota doesn’t want to spend the money to fix. Hino probably has a clause in their contract that doesn’t hold them responsible unless it’s a safety issue.

people are gonna start fucking up there differentials and cabs trying any kind shit to get the noise to go away, to me that makes it a safety issue.

 

my highway speed limits are 45 to 55 so I am always stuck in that 10 mile an hour range where the whine really starts to scream. problem is once you hear it you can’t un-hear it. I can have the radio up pretty loud and still hear the whine pierce through it, it’s all I fucking here when driving.

Pardon my French, sometimes it gets me worked up.

 

That little bit of weight might have dropped the suspension just enough to get rid of it (driveline angles).

 

Good luck! I hope they can help you!

 

Yep.

 

Sounds more like harmonics to me. Kind of reminds me of one of the vans that had roof racks for ladders. Left empty the racks would howl when hitting the highways.

 

The suspension is so taunt in my truck it'd take far more than that cover to drop that suspension. I can sit on the tailgate the suspension barely budges...and i weight 200 lbs.

 

That's what we're all hoping I think.

My concern is that if it was harmonics, then that would imply it's caused by a design flaw which would mean all trucks (or all affected configurations) have the noise under the exact same conditions. But it looks as though that's not the case... some claim they don't have it at all, some say it happens on acceleration, others on deceleration, different speed ranges, etc.

To me the symptoms seem to point more to manufacturing inconsistencies with the ring and pinion, or gear setup. Maybe harmonics are playing a role in amplifying the noise in the cabin? It's possible. The different symptoms between trucks is what concerns me though, and the fact that some simply don't have it.

I"m hoping that changing the oil out with something thicker, maybe non-synthetic will at least reduce the noise. If I could get it down even 30%, that would be worth it IMO.

 

Just curious if all the trucks that are howling have these rubber things between the bed and the cab, plus on the bottoms of the rear quarter panels.