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

Question for you guys that had a replacement diff done (or anyone that knows I guess too).

I checked my work order for the replacement and there is a line item for Limited slip oil additive.

I didn't think these trucks had mechanical LSD's. I thought it was controlled with the brakes and not actual clutch packs inside. Did you guys that got replacements have this line item as well?

 

Nope

 

I don't remember seeing a line for limited slip additive on my work order, but that was a while ago. I will take a look to confirm when I get off work.

 

I'm at work right now and I'd run out to the truck and check but my glove box had gotten so full of Toyota work orders and receipts that I had to take them all into my home office and start a file for them. I've never had to do that with any previous vehicle. I guess it's a combination of too many trips to the dealer and an owner's manual the size of a phone book.

 

I use them as padding around the owners manual so i don't hear it slide and clunk around in the glove box. I like to look at it as a nice "feature."

 

Update: Called Toyota to let them know the 2nd diff howls too. They said they are going to escalate it to a case manager. The dealership wanted me to bring it back, but we both kind of agreed there isn't really much else they could do since they replaced the whole carrier assembly. So we'll see what happens moving forward.

Toyota did grant me a 7 year, 125k mile platinum warranty for the troubles so I do give them credit on that. I'm happy to have that.

Will let everyone know what happens next....

 

I am kinda surprised that Toyota hasn't halted diff replacements for this symptom yet....There have been a ton of us that have had a replacement, and have told the dealer that we still have an issue....

 

It is probably a lack of communication or simply a process requirement. They can't halt all differential replacements or else people with a serious issue wouldn't get a new one. So it has to be left up to some level of employee to make the final call. Which in my case seemed to be the field engineer. So the field engineer was told by the service techs that "Yeah, there is an issue with the differential that in our experience isn't normal" so the field engineer either has the option of 1. Authorizing at least an "attempt" to fix the problem or 2. Denying the fix and leaving open the possibility of it actually being something serious that potentially ends up a disaster (ethics nightmare).

So from a company standpoint, it is easier and safer to replace it unless they can be 100% sure that it is not an issue. Unfortunately for all of automotive history a noisy differential has been an issue.

So now, the real question is what is happening with the differentials, especially if what one member stated is true and Toyota is determining that there isn't really premature wear. Is their final stop the boneyard or do they end up back on the shelf as a warranty replacement item?

 

My 2nd whines, but with the extended warranty they gave me, I'm just going to drive it. If it goes out again it goes out. Otherwise, I'm holding out till there's a real fix.

In the meantime I put some rougher tires on and that helps muffle it

 

I brought this issue up early on and was told it was normal. In my words, i was getting gear whine from the rear end under light throttle conditions. Tech told me it's just how they are. My 2006 had the same noise, even after I replaced the third with an ECGS ARB unit.

 

True....this is an interesting issue for sure. The field rep okayed my diff replacement as well. The same field rep was told by Toyota that it is normal after he examined my second diff. That is the only reason that I am surprised they haven't halted it for this specific symptom on relatively low milage trucks.

Totally agree that they would like to air on the side of caution in situations like this if at all possible.

 

Aside from some mechanical lockers, properly set up, hypoid gear type rear end assemblies (like we have) don't make noise (that you can hear in the cabin)... unless something is damaged or out of spec.

 

The facts:

1. A lot of howlers exist
2. Most of them started howling after a few thousand miles
3. Many (most? all?) still howl with a new diff

The logic therefore seems to indicate that it is something else making the noise. Or some change in the truck (or its behavior) is causing the noise to be made by the differential.

I think they need to look elsewhere - the differentials, if bad, are being caused to go bad by the truck - and probably not from poorly manufactured differentials.

Just a thought...

 

are the people having this issue double cabs or AC or both??? any one have it on a AC?? i have a off road 4x4 AC at 3k miles and i have not heard that howl. i broke my truck in really mellow and now after hearing about this im thinking about changing out the DIFF fluid early

 

Mine was basically a grocery getter for the first 500 miles.
I thought I might have had the whine; it's just the damn window seal.
I changed my diff fluid out at 5,000. I'm at 7,500, still nothing. I wish I would have done it around 500; it was low by a 1.25 quarts.
I believe Aussiek2000 changed his at 800 miles and he doesn't have the whine.
We both used Redline 75W-85 GL-5.

I say, change it out.

 

Has anyone, with a nasty rear end howl, checked the ring gear for out-of-round (with a dial indicator)? How about the ring and pinion gear pattern in at least 4 areas of the ring (pictures of the mesh pattern would help)? Also has anyone checked the ring and pinion backlash at multiple point around the ring? This information would be useful. I would check mine, but I don't have the Joel.

 

I'm not mechanical enough, and I don't have the tools or I would.

I also don't want to void my warranty. It's the only thing keeping me with this truck.

 

Found this comparison interesting; middle one shows a torsional damper.
I wonder codes RC60 and RC61 are?


With locker


Without locker

 

Probably a good idea. Mine had the whine before 500 miles. Some have said they whine right off the lot with only 10-20 miles. Something just barely off with some of these trucks that makes them howl. Hard to find these types of problems.

 

"Whine" usually indicates an incorrect pinion depth, an incorrect backlash, or gear pitch problem.