Rear axle whine

[4Rman]

Hello everyone,

Need your help! I have a 2005 4x4 SR5 V6 26k miles. Last month or so I have noticed that there is a whining noise coming from the rear of the truck. It only happens when I have my foot on the accelerator around 60mph and goes away if I let go. It cannot be the tires as taping the gas ever so slightly will not make a difference. It does not matter whether I am in 4D or D. It almost sounds like the classic rear end whine. Before I take it to the dealer and he tells me that dreaded "Cannot duplicate the problem" I wanted to ask you guys if anyone else has had to replace and/or fix anything in the rear axle assembly. Any help would be greatly appreciated.

Thanks

 

[Even Steven]

Hello everyone,

Need your help! I have a 2005 4x4 SR5 V6 26k miles. Last month or so I have noticed that there is a whining noise coming from the rear of the truck. It only happens when I have my foot on the accelerator around 60mph and goes away if I let go. It cannot be the tires as taping the gas ever so slightly will not make a difference. It does not matter whether I am in 4D or D. It almost sounds like the classic rear end whine. Before I take it to the dealer and he tells me that dreaded "Cannot duplicate the problem" I wanted to ask you guys if anyone else has had to replace and/or fix anything in the rear axle assembly. Any help would be greatly appreciated.

Thanks

Every 4Runner I've ever driven has a very slight gear whine coming from the rear differential. It's a very faint sound, but it's definitely there if you really listen for it. But I like that kind of stuff because I'm kind of a gear head and I appreciate the mechanical sounds made by an engine, transmission, and associated drivetrain components.

If your annoyingly loud or something?

 

[Ghostface80]

Never noticed it on the 4runner. Check your floor for any drops of differnetial leak. I let this go by for a few months on my mustang and by the time it was 'too loud' it was already too late and had to get new gears. Just like you, the whine only came when I was going 60+ mph.

 

[Road Warrior]

I found that the 'whine' sound reduced greatly when I changed the rear diff fluid (@29K miles) to a group IV synthetic.

 

[4Rman]

Road Warrior: Did you have the dealer do the rear diff oil change? Will the "group IV synthetic" void any parts of the warranty? And lastly, was it covered under warranty?

 

[RamThis]

Mine does not have a diff whine at all.

Might have them pull the cover and look at the patterns and tooth wear. If it's whining, there's a problem. Pinion depth may be deep or shallow, or lash may be too tight or loose. A bad carrier or pinion bearing will make noise all the time, and a pinion bearing may get a bit louder under a load and drop it's volume a bit under coast. Seen that one for myself before (inside pinion bearing race pitted)

I've setup quite a few hypoid gearsets in different equipment, bot my Rams, a few newer Mustangs, and some friend's trucks, I know a whine from the gearset means the teeth are not meshing flat or in the proper place on the tooth itself.

Get it checked out soon by the dealer. You're still under warranty anyway.

 

[4Rman]

Thanks Ramthis. Great information.

Do you think the dealer would know as much as you and would be willing to listen. It has been my experience in the past, that they do not like to admit there is problem and want to send you on your marry way. As an example, the pretensioner in my seat belt stopped working last year so my seat belt went limp and would not retract normally. I could not convince this idiot that there is a problem with the belt. I finally told him to go sit in one of the new 4Runners on the lot and see how the seat belt feels. Well, that did the trick. He had to argue with me for 1/2 hour in front of other customers but in the end had to eat crow. I just dread going to the dealer that's why I wanted to get as much information as possible. I have yet to come across one that is more interested in fixing the problem rather than convincing you that everything looks good. May be I'll print your replay and take it wit me to the dealer.

Thanks

 

[RamThis]

I would hope being the dealership, employing ASE certified technicians (I am not ASE certified, just that I've worked on everything from lawnmowers to F-16's for Lockheed lol) that they would know as much or more about hypoid gearsets as I do!!

True though that unless you have to bring the vehicle in on a wrecker it's sometimes hard to get them to admit there's a problem. I'd do something similar to your seatbelt problem and have them ride with you and listen to what you hear, and then maybe ride in another 4Runner from the lot, same trim level, and show them the difference.

Sometimes a gearset can be off just enough it causes a harmonic vibration in the ring gear but still not cause any damage to it, just that under certain axle speeds it will act a bit like a tuning fork and vibrate a bit and that's what you hear. A slight adjustment of the pinion shims will usually correct it.

As an example, I let a friend do the gears in my 96 Ram and I just installed the Detroit locker and set the lash since I was short on time. He just took the stock shims from the stock pinion, and slapped that on the new pinion, and thought it was good. Never checked patterns. The truck does have a slight harmonic whine around 45 mph.

My 2000 Ram, I did the gears with no help. I spent a full 8 hours, and installed/removed the pinion and carrier about 6 times until I got the pinion depth perfect and the patterns showing perfect. Installed the gears with about 15K miles on the truck. It's at 85K miles now, and the gears are totally silent.

It's all in the pinion depth/lash settings that keep the gearsets quiet.

 

[Road Warrior]

Road Warrior: Did you have the dealer do the rear diff oil change? Will the "group IV synthetic" void any parts of the warranty? And lastly, was it covered under warranty?

No , I did it myself No the warranty will not be voided. No I didn't even think about warrantying it...because I didn't notice it until after I changed it. I wouldn't have said "the rearend in this thing is loud" prior to the change...which would make it hard to warranty. But it was noticably quieter after it was changed. Typically, unless things are grinding or whatever, I think it is unlikely for anyone to bring a car in and say "I think you should check the whine coming off the rear end at speed...", especially a 4X4. Most people have no way to draw a distinction between a quiet rearend and a noisy rearend (except for flatulence, LOL) . The stealership could probably check it by disassembly or temp, but I think that would only happen in extreme cases.

As you can see by the replies, this subject is a bit "subjective".

 

[4Rman]

Thanks for the replies so far. Special thanks to RamThis.

I am thinking about taking it to a local mechanic first to see if he hears the same noise as I am hearing. He is more likely to have an open mind compared to the Stealer. This way I can have a professional backup my claim.