gm service bulletin 05-06-05-002 - Vibration 1700-1800 rpm
Gm fix replace converter and muffler assembly
2500/3500 short box extended and crew cab models with lly.

This is a quote from this link http://dieselplace.com/forum/showthread.php?t=24776&page=6 regarding the LLY "droan" noise.

Does anybody know if this info is good? I can't find any evidence of it on AllData etc

Thanks!

Rob

Anybody?? Fact or Fiction?? PM'ed the author - no response.

it is a legitimate gm bulletin I pulled it up it is for 04 and 05 chev and gmc 6.6l vin 2 lly

Thanks for the info! I'm guessing that it is a TSB - would it be asking too much for someone to post the text. This is going to help alot of LLY owners.

Thanks again for the response!!

Exhaust Moan/Vibration (Replace Converter Assembly and Exhaust Muffler Assembly) #05-06-05-002 - (Jul 27, 2005)
Exhaust Moan/Vibration (Replace Converter Assembly and Exhaust Muffler Assembly)
2004-2005 Chevrolet Silverado 2500HD/3500HD Series Crew Cab Short Box Pickups

2004-2005 GMC Sierra 2500HD/3500HD Series Crew Cab Short Box Pickups

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

Condition
Some customers may comment on a moan or vibration at vehicle speeds approximately 87-97 km/h (55-60 mph) and at approximately 1700-1800 RPM.

Correction
Replace the catalytic converter assembly and exhaust muffler assembly using the procedure listed below.

Exhaust Moan/Vibration (Replace Converter Assembly and Exhaust Muffler Assembly) #05-06-05-002 - (Jul 27, 2005)
Exhaust Moan/Vibration (Replace Converter Assembly and Exhaust Muffler Assembly)
2004-2005 Chevrolet Silverado 2500HD/3500HD Series Crew Cab Short Box Pickups

2004-2005 GMC Sierra 2500HD/3500HD Series Crew Cab Short Box Pickups

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

Condition
Some customers may comment on a moan or vibration at vehicle speeds approximately 87-97 km/h (55-60 mph) and at approximately 1700-1800 RPM.

Correction

Replace the catalytic converter assembly and exhaust muffler assembly using the procedure listed below.

Thanks MIKEK996! You've helped alot!!

Hey Mike,

Can you please post the entire bulletin?

Thanks alot!

the rest is only R&R procedures its real long.

What is the difference between the factory installed CAT/ exhaust and the replacement one??

Thanks!

Rob

I dont really know gm doesnt tell us stuff like that. If I had them side by side I might know. there may be heavier pipe or an extra bracket of some sort. are you still under 100k?

I dont really know gm doesnt tell us stuff like that. If I had them side by side I might know. there may be heavier pipe or an extra bracket of some sort. are you still under 100k?

Yep - only at 23K - will be going in next week for warranty repairs.

Hey Mike,

Can you please post the new part #'s for the update? I want to call the dealers in the area to see if anyone has it in stocl. Hopefully my dealer does, I would rather not wait a week!:rolleyes:

Part Number
Description
Qty

15229341
Converter Asm. -- Oxidation Catalytic
1

15229356
Muffler Asm. -- Exhaust
1


Warranty Information
For vehicles repaired under warranty, use:

Labor Operation
Description
Labor Time

L9707*
Exhaust System (Complete) - Replace
1.6 hrs

I doubt anyone is stocking this

Thanks for the infor MIKE,

I was able to look up the parts on GMPARTSDIRECT.com (about $600 combined).

This may be a silly question, but where is the G.M. Tech Bulletin regarding the 1700-1800rpm groan or droan? I think I looked at every post and I can not seem to find it. My truck goes in next Tuesday and my dealers service writer is a female and she has no clue as to what I was talking about, when I tried to explain what needs to be done.
I think if I had a copy of the bulletin, she may then be able to figure out what needs to be done.
I have the feeling she is the type, if its not in her computer then there is nothing wrong and she will not help.
Because, I installed a set of the factory fog lamps in my truck and they work fine, but the instructions state the BCM needs to be programmed to recognize them. Her attitude was if a dealer didnt install them, she won't do a damn thing.
My salesman I talked to said if they work the way they are supposed to then screw her and let it go.

Give her the service bulletin number and tell her to look it up in their computer. The dealers I'm dealing with can find the info - I just can't get any of them to commit to the repair even though I have a warranty repair dated last November documenting the problem. At that time they installed the exhaust dampner as a possible fix but it didn't fix it.

I'm getting frustrated and about ready to place a call with GM customer service.

Ok thanks I will do that and see what happens. I am not going to hold my breath though.

i'm going in this morning for mine. my local dealer actually had the parts in stock, I asked if they were special ordered for someone else and they said no. I will go with bulletin in hand. I will post results later today.

I did some checking today on parts availability. The "converter" is available for shipment. The "exhaust system" is unavailable ("no available inventory"). This was per a local GM dealer's parts department.

Sounds like GM knows what the fix is but they do not have the parts to fix it. Sounds like the updated intermediate shaft story all over again! Uuugh!

Just got back from the dealer. After going round and round with the service writer, having him tell me that I don't have that problem and telling me the TSB does not describe what I was telling him, (although my complaint and the TSB are/were identical) he reluctantly said they would do the fix and had to order parts. :mad: I kindly told him he had the parts in stock and I would like it fixed today. He was shocked to say the least, and somewhat angered. 1 Hour later I had my truck back, went for a ride with him, and proved to him I was correct and he was wrong!:ro) The droan is 99% gone, but still there a little, definately a big improvement.

I just hate dealers who outright lie to me and treat me like I am a dumb a**. It pisses me off when they blatently do that. I know when I am right and today I proved it to him.

Bottom line is this the TSB is a 99% cure, and dealers suck!

Also, the new converter and muffler assembly does not have a 4 bolt flange like the old set up, it has a straight pipe with a pipe clamp holding the two together. Is this how the LB7 is? Notice the TSB only pertains to LLY trucks?

thanks

http://www.alldata.com/tsb/General-Motors/1122447600000_1128582000000_05-06-05-002/index.html



That is the link to the Tech Bulletin for the droan. It includes all the steps to fix it. My truck goes in Tuesday to my dealer and the service writer, sounds reluctant do to anything. I found a closer dealer and service writer told me if there is a tech bulletin that says replace the exhaust and thats what he will do.
I am going to print out the entire bulletin and take it with me and see what my dealer says......Probably going to be a waste of 90 mile roundtrip.

Thanks for the info KEN!

http://www.alldata.com/tsb/index.html





This is a link to Alldata. Its list of tech bulletins for just about all makes, not just Chevy's

Update: As previously stated I got the run-around from two previous dealers I approached re: the TSB "no parts available" "Need your truck for the day to re-diagnose it"...........finally went to a local small dealership, explained my plight and asked if they would do the repair. He didn't see a problem doing it as it had already been diagnosed and the dampner was installed in an attempt to fix it. Said he didn't need the TSB # because he could find it by running my VIN. He called me today saying he couldn't find a record of the TSB. I stopped by and showed him the TSB and the ALLDATA info on the procedure to fix it. He was surprised to say the least and still couldn't find it in his computer. He is going to get the info from their GM rep tomorrow and call me back to confirm the parts are ordered. For good measure I also gave him the PI number (thanks to our member for posting the info). He asked where I got it and I told him "it's amazing what you can find on the internet". An informed consumer is a smart consumer!

......to be continued........

Just got back from the dealer. After going round and round with the service writer, having him tell me that I don't have that problem and telling me the TSB does not describe what I was telling him, (although my complaint and the TSB are/were identical) he reluctantly said they would do the fix and had to order parts. :mad: I kindly told him he had the parts in stock and I would like it fixed today. He was shocked to say the least, and somewhat angered. 1 Hour later I had my truck back, went for a ride with him, and proved to him I was correct and he was wrong!:ro) The droan is 99% gone, but still there a little, definately a big improvement.

I just hate dealers who outright lie to me and treat me like I am a dumb a**. It pisses me off when they blatently do that. I know when I am right and today I proved it to him.

Bottom line is this the TSB is a 99% cure, and dealers suck!

Also, the new converter and muffler assembly does not have a 4 bolt flange like the old set up, it has a straight pipe with a pipe clamp holding the two together. Is this how the LB7 is? Notice the TSB only pertains to LLY trucks?

thanksthats a little harsh

thats a little harsh

Mike,

yeah your right, I was quite angry after that. However, how do you feel when you are being lied to and you know it?:mad: I absolutely hate it, it makes me so mad, especially when it is done in a manner that tries to make me look stupid!

Update: As previously stated I got the run-around from two previous dealers I approached re: the TSB "no parts available" "Need your truck for the day to re-diagnose it"...........finally went to a local small dealership, explained my plight and asked if they would do the repair. He didn't see a problem doing it as it had already been diagnosed and the dampner was installed in an attempt to fix it. Said he didn't need the TSB # because he could find it by running my VIN. He called me today saying he couldn't find a record of the TSB. I stopped by and showed him the TSB and the ALLDATA info on the procedure to fix it. He was surprised to say the least and still couldn't find it in his computer. He is going to get the info from their GM rep tomorrow and call me back to confirm the parts are ordered. For good measure I also gave him the PI number (thanks to our member for posting the info). He asked where I got it and I told him "it's amazing what you can find on the internet". An informed consumer is a smart consumer!

......to be continued........


Got a call from the dealer....he says that he was able to pull up the info right away this AM on his computer (I'm guessing he did some kind of update). His GM tech still hasn't called him back but he is going to order the parts anyway and let me know what the availability is.

The service writer (female) was unsure, when I explained my problem the first time. When I went back Tuesday I talked male service writer and showed the tech bulletin.......they had my truck in the shop for less than ten minutes and the male service writer came out and told me they were going to order the parts on the tech bulletin.
I was standing there with my salesman and he asked how long would it take to install.....The service writer replied a little over a hour and a half.
Exactly what the tech bulletin states....imagine that!!!!!

My salesman questioned the service writer he wanted to know if I needed a loaner vehicle or not.
So far the Wiers Chevrolet in Demotte, IN, have been pretty good to me.

I'm curious as to whether this is the cure. Hope it is. To my knowledge only one member here has had the fix done and he report it as a 99% cure.

Can't believe that more of the LLY guys aren't jumping on the bandwagon. My droan is def, worse in cooler outdoor temps. Didn't bother me the past 5 months but quite annoying now. Maybe a regional thing???

Mike,

yeah your right, I was quite angry after that. However, how do you feel when you are being lied to and you know it?:mad: I absolutely hate it, it makes me so mad, especially when it is done in a manner that tries to make me look stupid!yes is is too bad that they treated you like that. but it really boils down to the fact that GM doesnt give 2 sh#ts about their techs so in turn some dont take the time to properly diagnose some problems. sometimes I have to drive a vehicle for hours and I get paid .3 tenths to diag thats only 15 minutes. that is why when techs see a dmax pull in they go hiding hoping to not get the job. flat rate system is ok but on warranty end of it usually the tech gets screwed. like those injectors we are supposed to be able to diag and replace 8 injectors the fuel filter and lof in 8.0hrs (thats what it pays us) last one I did took 12plus hours. and a lot of people say "they dont care that I just spent 40 grand at their store" but the service dept sees none of that. that goes toward the salesmans 6 figure income. . sorry just ranting a little.

Dealer called today. Said the new CAT is in, still waiting on the rest of the exhaust. He thinks it will be in within a few days.

My Dealer called today and said my parts finally showed up. Hopefully, tomorrow or Friday I can get my truck in there and fixed.
With any luck this will fix this nuisance.

My Dealer called today and said my parts finally showed up. Hopefully, tomorrow or Friday I can get my truck in there and fixed.
With any luck this will fix this nuisance.

Let us know how you make out.

How long did it take for your parts to come in??

They ordered the parts the 18th and they came in this morning. I hope this works.

They ordered the parts the 18th and they came in this morning. I hope this works.

Me too!

Thanks!

The new re-designed exhaust was installed last Friday. I would estimate the droan/resonance is 90% gone. It could be I have become so accustomed to the noise, I am trying extra hard to hear it.
It appears the re-design is:
1. They eliminated the flange connection between the cat assembly and the muffler assembly. GM converted the flange to a butt joint with a single large clamp holding the 2 pipes together. (I am not sure if its called a butt joint or not)
2. The tail pipe end is cut straight instead of being beveled. The new pipe appears to be angled to the rear more than the stock.
3. If I remember right the joint between the cat assembly and muffler assembly has been moved farther back, closer to the muffler.
I took a few pics and I will try to attach them below

Good work Ken!

The pic you posted which contains the axhaust and CAT - that's a picture of the old exhaust, right?

I wonder what if anything changed internally in the muffler & CAT design. Seems like they had to change more than just that clamp.

That is a pic of my old exhaust. I couldn't get a pic of the new exhaust when they had on it floor sitting next to the old one. My truck was on the lift, along with my camera.
When they were sitting side by side, only differences I noticed were what I descibed in the previous post. I asked the service tech and the parts manager what was redesigned and they both said the only thing they knew of was the clamp. The service tech did not even know where on the old exhaust the noise was coming from. The service tech said if there was a complaint and a tech bulletin says how to fix the problem, then he just fixes it according to the bulletin.
Hopefully, your dealer knows more than mine did.

that is the same set up my truck has (after the TSB). this also appears to be the exhaust for the '06 trucks. I have noticed the droan is much less, but seems to be at about 1500 rpm. like I said before, it was about a 99% cure for my truck.

My parts are in. Going to the dealer on Thursday for the install. I'll try to grab a pic of the new exhaust and post it.

Good luck with your fix. After a few days of driving my truck, the droan is becoming less noticeable each day. Hopefully, I am learning to tune it out or I am turning up the radio more):h

FYI - the numbers on the side of the muffler of the original /"old" exhaust system are:

2015426

1 265 4 A

I'll compare them to the numbers on the new muffler to see if maybe they changed mufflers on us. Less or more back-pressure maybe??


Ken,

BTW - I took pics of my old exhaust last night while still on the truck - your old exhaust was waaaayyyy to clean!! Good god, yours still had the stickers on it!! :)

The old exhaust should still look clean....truck doesn't even have 6,000 miles on it.
Truck has only been off road once.....and thats because I had to pull on to a farmers access road to a corn field so I could pee:rolleyes:

FYI - the numbers on the side of the muffler of the original /"old" exhaust system are:

2015426

1 265 4 A

I'll compare them to the numbers on the new muffler to see if maybe they changed mufflers on us. Less or more back-pressure maybe??



Numbers on the "new" muffler are

2015426

1 286 5 A

Manufactured by Arvin Maritor Exhaust, LLC Dexter, MO

Different numbers between old & new FWIW. Sorry, couldn't get pics of the new exhaust before it went on the truck.

I'd say that the new exhaust cured my Droan about 90% but I've only driven it about 5 miles since it was installed.

Just got mine back last night from the dealer taking advantage of the free oil and filter change they were offering. I had several items for them to check into along with this one. They replaced the cat and muffler without any fuss. I'd say the noise is at least 80% reduced.):h

I wonder if anyone who has done the cat delete and gone with a 4" exhaust system has any issues with it at all ?