LBZ drone

[moss6]

Our 06' has a low pitch drone around 65mph (plus or minus two to three mph); this drone is strong enough that you can actually feel some minute vibration that accompanies it. I noticed it in another truck that we drove before ordering ours but didn't think too much about it at the time. That said it must be fairly common place and inherant to the 06' or the LBZ?? Some exhaust advertizers claim their product eleminates an exhaust drone I have seen other complaints also but they seem relatively rare and I have seen no explaination of the cause nor the cure; seems GM does not officially recognize it.
Anyway it is very annoying and makes you avoid that speed, which by the way is the legal speed limit on many hwys! Does this bother any of you, or maybe none on this forum have noticed; I did a search and it did not come up. Input welcome, thanks.

[DieselMonk]

Not that I noticed that on my 07 Classic. Now I have an Magnaflow dual anyway... :D

[mark45678]

I noticed it when my 2006 lbz was new , now that you bring it up I dont notice it any more.... could be due to the fact that i did a cat back mbrp system , cant say for sure. Once these truck get some miles on them they do change . loose up for the better. Dont worry about the drone its a very narrow speed it does it new and it seams to have gone away after a few months. My truck has 33,000 mile on it now , only issue was the "lube job" .... you would think Gm would get there head out of there ASS and find a cure rather then waiting for complaints.

[Duramaster]

AH HA!!!!! I did some research!!! Check this out and show this to your dealer.

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Subject: Exhaust Moan Drone Vibration At Approximately 1700 RPMs - keywords 6.6 LLY LBZ resonance noise buzz #PIT3457D - (03/27/2007)



Models: 2004-2007 Chevrolet Silverado Classic 2500HD/3500 Series

2004-2007 GMC Sierra Classic 2500HD/3500 Series

with 6.6L Diesel Engine (VIN 2 or D - RPO LLY or LBZ)




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This PI is being superseded to update models. Please discard PIT3457C.


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The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:
Full size trucks equipped with the 6.6L LLY and or LBZ engine may have an exhaust moan/drone/vibration concern at approximately 1700 RPMs

Recommendation/Instructions:
If working on a 2004-2005 crew cab short box pickup follow bulletin 05-06-05-002. All other models have had success reducing the concern by installing two exhaust dampeners, part number 10199232, five inches forward of the catalytic converter.

Note: If working on a 2006 or 2007 crew cab short box pickup or after performing bulletin 05-06-05-002 on a 2004-2005 crew cab short box and the concern is not corrected to the owners satisfaction, two exhaust dampeners, part number 10199232, can be added 17 1/2 inches forward of the catalytic converter.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed
;)

[moss6]

Thanks, you are really good at coming up with good info. Is there any way to access the actual bulletins?

[DmaxMaverick]

....Is there any way to access the actual bulletins?


www.alldatadiy.com

[Duramaster]

That is the actual bulletin from the ACTUAL GM SI WEB SITE. The images just don't paste when I copy and paste. I am a GMC Technician at a Dealership in Portland, OR and I have access to all sorts of good info!:cool:

[Jason.Benjamin]

Duramaster,

With access to "ACTUAL GM SI WEB SITE"

Could you chime in on reprogramming the ECM for the Mirrors?
http://www.thedieselpageforums.com/tdpforum/showthread.php?t=27081

[moss6]

Being a GM Tech I thought you might enjoy.

I went in yesterday to talk to the dealership about fixing the drone per the tsb that you provided. I had called the parts dept. beforehand and found that they only had one weight, so I went in and asked a service writer if he would order an additional weight so that when we brought the truck in we could get the service done on the original trip rather than having to return when the parts were available. He responded that we would have to bring the truck in first before they could order the additional weight and that they could not order parts just because a CUSTOMER requested them!
Ticked yes! So I went to the owner who is a friend and told him about the young service writers advice. The owner directed me to the service managers office where I gave him the bulletin number and he pulled it up on the computer. I asked him if they had done the proceedure on any other trucks and he replied no that they had had no trucks with the drone. He commented that it was not normal proceedure but that he would order the addition weight so that they would have it when we brought the truck in. I told him I appreciated the gesture and then posed what I thought was a legitimate question "I wonder why our truck has the drone and you have had no other trucks out of this large dealership that exibit this annoying problem that GM deemed bad enough to issue a fix for. I also am curious as to what could actually cause the drone." He went into a spiel about tuning a guitar and the harmonics involved. I agreed that I might buy the theory, but if that was the case why wouldn't it be far more prevalent than what he would have me believe.
----He said that all the trucks were different; different tire sizes and axle ratios etc. I said no, I mean 2006 2500HD shortbed crews just like mine, they are all pretty much alike aren't they? He said no that they have lots of different tire sizes and axle ratios, go ask a salesman, I don't want to argue about it.---

What gives with that; I understand that GM is pretty sticky about tire size on the Duramax/Allisons and I really can't imagine that too many are ordered with anything other than the 3.73----matter of fact I thought that the only option was the 4.10. Maybe there's more to it. This, buy the way, is normally an excellent dealership.

[DmaxMaverick]

All Duramax equipped pickups can only be had OEM with one gear ratio (3.73), and one tire size within the model. Specific models (2500HD, 3500SRW, 3500DRW) will only be available with the tire/wheel size available for that model. There is no option for tire size. That SM is misinformed, among other possible shortcomings.

[Duramaster]

LOL MOSS!!! Yeah, the DMAX only comes with 3.73 gears and there ARE TWO different tires offered. One is definitely a highway tire and the other has a little more aggressive tread, but regardless there is only one tire size offered (Until now with the new body truck that is). :rolleyes:

That's ok. I disagree with alot of my Service managers thought also, but I just have to grin and bear it.;)

[moss6]

Took the truck in this week to have the TSB correction done to quiet the drone. I must say I was somewhat skeptical of it actually being a cure; maybe a little improvement (as we saw in the 01' 6.0 we had) but not an elimination of the drone. I am happy to say I was wrong, as the adding of the weights to the exhaust forward of the cat TOTALLY eliminated the noise and vibration. A rarity that I am completely satisfied with service work-----but good job GM is in order.

[Dakster]

It could just be that the drone bothered you and not alot of people enough to bring it in to fix it. I know a lot of people that just deal with a vehicles annoyances rather than try and figure out how to fix it. I am like you though, very picky and I want the vehicle as perfect as possible. Especially after dropping 50k on it... Glad it fixed your issue.

[Duramaster]

:) I'm glad that the weights fixed your drone annoyance. Happy Trucking!! :)

[Duramaster]

I just put a set of weights on a 2007 CC longbed Sierra Classic LBZ (today):) . Seemed to have taken care of it.

[moss6]

Duramaster,
I'm curious about what you thought about the drone before you fixed it; say on a scale of one to ten for annoyance, as the doctor would ask. If I'm the only one that has taken a trunk in for the fix at my dealership; am I just overly sound sensitive or what? I thought the drone was highly offensive and embarrasing especially when a new passenger would ask what the sound and vibration was.

[EdHale]

Thanks guys. I had never noticed the "drone" until last night when towing my boat 210 miles to the lake for the weekend. I always have felt more comfortable towing at 65mph even though the truck will tow as fast I would want to go. Never thought about the "drone" and now that I am aware of it, it is driving me crazy!!!!

!@#$%!@#$%%$#@

Ed

[Dakster]

Thanks guys. I had never noticed the "drone" until last night when towing my boat 210 miles to the lake for the weekend. I always have felt more comfortable towing at 65mph even though the truck will tow as fast I would want to go. Never thought about the "drone" and now that I am aware of it, it is driving me crazy!!!!

!@#$%!@#$%%$#@

Ed

My case in point by Ed's post above...

I would never say anyone is "overly" sensistive to drone and vibrations. Just that some people I know, don't consider it an annoyance, and live with drones and vibrations. Other's don't or can't take their truck down to fix an issue that doesn't prevent the operation of the vehicle. A new vehicle should be (or fixed to be) perfect. No shakes, rattles, drones, funny noises, wind noises, and everything should work.

I was merely playing devil's advocate as to why a TSB may not be issued on a drone. During warranty, the dealer will fix everything and anything that goes wrong on my vehicles. I have had them replace discolored emblems and mismatched knobs in the center console. I'd say I'm a pretty picky customer. I do demand that I get exactly what I paid for, nothing more, but certainly nothing less.

[Duramaster]

The drone on the last truck was not as bad as some. The owner is actually hard of hearing. He was actually complaining of the "vibration" that he felt in the floor. I believe the this was his second DMAX but his other one was a 2001. And his new one is a 2007 Seirra classic. Honestly I didn't notice any difference nor did I find it objectionable.?? I'm not the owner with the picky foot though!:)

[EdHale]

I will be driving the 210 miles back home with my boat this afternoon so we shall see if it still bothers me. I doubt very seriously that I will make a special trip to the dealer to get it fixed. Maybe if there for something else I might mention it. We shall see. Ed

[EdHale]

The trip back from the lake yesterday with the boat was during the daytime vs the evening trip to the lake on Friday. With the extra traffic to keep me occupied and the radio on, I didn't notice the drone at all. Oh well. Ed