Has anyone installed the "revised" differential dynamic damper assembly themselves?

[JEL]

Has anyone installed the "revised" differential dynamic damper assembly themselves?

I have that annoying harmonic drone when driving down the highway in 4hi unlocked. It starts to show up around 60mph and goes away when I go over 70mph, but it's really starting to annoy me. I want to give the revised diff damper assembly a shot, but the TSB was for Lexus GX trucks. I assume the revised damper would work on our 4runners?

Here is the TSB in question:

http://www.alflash.com.ua/avtovideo/2005l/L-DL001-08.pdf

 

[Jeremy556]

Seems like using 2wd would be easier.

 

[TrdLtly]

I have that annoying harmonic drone when driving down the highway in 4hi unlocked. It starts to show up around 60mph and goes away when I go over 70mph, but it's really starting to annoy me. I want to give the revised diff damper assembly a shot, but the TSB was for Lexus GX trucks. I assume the revised damper would work on our 4runners?

Here is the TSB in question:

http://www.alflash.com.ua/avtovideo/2005l/L-DL001-08.pdf

To me, a damper only disguises something that is not right.

Did you already read this thread? http://www.toyota-4runner.org/4th-gen-t4rs/105459-driveline-drone-freeway.html

 

[RPS13]

To me, a damper only disguises something that is not right.

Did you already read this thread? http://www.toyota-4runner.org/4th-gen-t4rs/105459-driveline-drone-freeway.html

Vibrations are all over a vehicle that is operating normally, that's why there are numerous dynamic vibration dampers all over a vehicle.

Even if something is 100% balanced, it will vibrate at certain speeds (same principle as a tuning fork).

 

[JEL]

What got it all started was this thread:
http://www.toyota-4runner.org/4th-gen-t4rs/151034-inafamous-60-70-mph-moan-vibration.html

I've noticed it for about a year now, but it was probably doing it before. I found a few threads on t120, as well as tons on Lexus forums pertaining to the GX and the harmonic hum. There are other threads here as well where members have noticed the exact same thing, I"m just hoping it's not a bad front diff after all, as I'm already on rear diff #3 in less than 100k miles of easy driving and meticulous maintenance....:mad2:

 

[TrdLtly]

Vibrations are all over a vehicle that is operating normally, that's why there are numerous dynamic vibration dampers all over a vehicle.

Even if something is 100% balanced, it will vibrate at certain speeds (same principle as a tuning fork).

I was just stating that someone could disguise a problem (ie bandaid) for something that could be wrong. We have all heard the tires going down the road making all kinds of noise due to lack of proper maintenance such as balancing, alignment, worn tie rods, worn ball joints, etc.

The thread I mentioned could have installed a damper only to have the rear end seize up because they did not replace the pinion gear.

There are other threads here as well where members have noticed the exact same thing, I"m just hoping it's not a bad front diff after all, as I'm already on rear diff #3 in less than 100k miles of easy driving and meticulous maintenance....:mad2:

That would be very frustrating. I used to do harmonic analysis on some systems with all kinds of fancy equipment. Not very easy to troubleshoot on a vehicle that has so many moving parts.

 

[TrdLtly]

I have that annoying harmonic drone when driving down the highway in 4hi unlocked. It starts to show up around 60mph and goes away when I go over 70mph, but it's really starting to annoy me. I want to give the revised diff damper assembly a shot, but the TSB was for Lexus GX trucks. I assume the revised damper would work on our 4runners?

Here is the TSB in question:

http://www.alflash.com.ua/avtovideo/2005l/L-DL001-08.pdf

Reading the TSB it says "complain of a vibration/drone felt in the floorboard or seat when maintaining steady speeds between 55 and 75 mph."

Are you feeling a drone or hearing a drone?

I would be interested in trying a couple of things. Take some weight out of the vehicle. Increase or decrease tire pressure a few pounds either direction. Try a different highway or interstate.

You may have tried these, but this is just some ideas for you or others for troubleshooting.

 

[JEL]

Reading the TSB it says "complain of a vibration/drone felt in the floorboard or seat when maintaining steady speeds between 55 and 75 mph."

Are you feeling a drone or hearing a drone?

I would be interested in trying a couple of things. Take some weight out of the vehicle. Increase or decrease tire pressure a few pounds either direction. Try a different highway or interstate.

You may have tried these, but this is just some ideas for you or others for troubleshooting.

Thanks for the replies, I have tried just about everything else but it still persists. I had the alignment done, as well as the wheels balanced twice, and the air pressure is spot-on with all my tires. It'll do it on any highway and only at those certain speeds. I can feel the hum through the floorboards, but VERY slightly and sometimes not at all. There have even been times where it won't do it at all even under the "ideal" conditions.

The part appears to be cheap and it looks like it would be an easy swap, as long as I don't have to drill and tap, so I may try it and be the guinea pig.

 

[fdbyrne]

If you do it, please report back. I've got the same issue and so does every other 2004 V6 4x4 4Runner that I've driven. I think some people are just more prone to notice (and be annoyed by) these sorts of things.

I drove an 03 or 04 Lexus GX470 the other day that did it as well.

 

[Gdmeadors]

I have to stop reading threads like this. I start getting paranoid that my 4Runner is going to have these symptoms.

 

[m85476585]

What got it all started was this thread:
http://www.toyota-4runner.org/4th-gen-t4rs/151034-inafamous-60-70-mph-moan-vibration.html

I've noticed it for about a year now, but it was probably doing it before. I found a few threads on t120, as well as tons on Lexus forums pertaining to the GX and the harmonic hum. There are other threads here as well where members have noticed the exact same thing, I"m just hoping it's not a bad front diff after all, as I'm already on rear diff #3 in less than 100k miles of easy driving and meticulous maintenance....:mad2:

I have exactly the problem described in the above thread:

so I have had this cyclical groan/vibration for a few months now between 60-70 mph it does it whether you are on the gas or take your foot off, it does it no matter if your in OD or 4th gear, i have re-greased all u joints to no avail

2005 V8 4WD
I put on new tires, no difference
you can only hear it with windows up, radio off and you can slightly feel it in the gas pedal it's cyclical (groan, not, groan, not) in 1 second intervals at 65mph

i'm gonna try changing the front diff fluid and check the fluid level though I doubt that's the issue I know plenty of others have had the same issues

any solutions, any help is greatly appreciated

For me it happens around 60-65mph, it doesn't matter if my foot is on the gas or not, and it's kind of a vibration and/or hum that increases and decreases with about 1 second intervals. Between about 45-65mph I can feel some vibration in the pedals and steering wheel. Above that wind noise and tire noise seem to be the main contribution.

It would be interesting to try 2WD to try to eliminate the problem, but that's not an option on the V8.

I thought I was going crazy, but I'm glad other people have the problem too.

To me, a damper only disguises something that is not right.

Did you already read this thread? http://www.toyota-4runner.org/4th-gen-t4rs/105459-driveline-drone-freeway.html

The problem described in that thread sounds different.

 

[TrdLtly]

I thought I was going crazy, but I'm glad other people have the problem too.

The problem described in that thread sounds different.

I feel for you guys as I know that it can be very frustrating to find noises let alone an annoying vibration. One thing that you may want to try is to eliminate the load. The load of the engine, tranny, and drivetrain could be causing the vibrations. At your own risk, I would try to put the transmission in neutral while going down the road or while you feel/hear the vibration. That may help to isolate the annoyance.

Vibration Isolation is a huge industry. It is a "mad science" kind of industry for sure. Just about anything with a moving part generates harmonics which in turn creates noise or vibration.

If it were me: I would spend as much time learning about vibrations in the automotive industry as I could to help me understand. If you Google just "4Runner Vibrations at 60-75 mph" you will see that you are not alone. It appears that the Taco's have a similar random problem.