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Posted

***Buffeting Update***

The ring and pinion backlash has been measured and was found to be out of required specifications. The ring and pinion was replaced along with the driveshaft. I went yesterday to drive the vehicle, but it was very hard to make a determination if this indeed solved the issue, as it was raining heavily at the time making it difficult to hear, but I believe I still heard the ‘buffeting’ sound.

I also contacted SPDYPRNT’s Service Manager to see if he could help. I have to say, he has gone above and beyond, even though he is over 1000 miles away and not physically dealing with my vehicle. He stated they did the same as my service above, but the ‘buffeting’ sound was not resolved until they replaced the side bearing races in the differential as well. These side bearings had an “hourglass” shape due to backlash being out of required specifications. He also was nice enough to send me the complete parts list and the technician notes on the repair.

I have forwarded this information to my Service Manager in hopes he will do the same. I am out of town today, returning tomorrow, and I hope they have time to make this last repair to the side bearing races before I arrive to test drive again.

I will update accordingly. Until then, here is the complete parts list and service order the other Service Manager was kind enough to send to me:

Parts:

QTY 2, 12471686 - SEAL, R/AXL SHF

QTY 2, 12479031 – BEARING, RR WHL

QTY 1, 14038010 – SHIM KIT, DIFF DRV P/GR BRG

QTY 2, 15286384 – RING

QTY 2, 22786619 – BEARING ASM – DIFF

QTY 2, 22835276 – SHIM KIT – DIFF BRG

QTY 1, 22934114 – SPACER, DIFF DRV P/GR BRG

QTY 1, 23114036 – GEAR KIT – DIFF RING & PINION

QTY 1, 23126912 – DIFFERENTIAL ASM/LSLIP

QTY 1, 23168731 – SPACER – DIFF DRV P/GR BRG

QTY 1, 23199120 – HOUSING ASM – R/AXL

QTY 1, 26063647 – CONNECTOR, R/AXL VENT HOSE

QTY 1, 12471607 – MAGNET, R/AXL HSG CHIP COLLECTOR

QTY 1, 22943108 – BEARING

QTY 1, 22943111 – SEAL

QTY 1, 22943106 – BEARING ASM – DIFF DRV P/GR INR

QTY 1, 114454 – AXLE ASSEMBLY

TECH COMMENTS:

Road test numerous times to pinpoint concern. Road test similar vehicle and verified concern is not present. Found concern to be most prevalent on decel at 43 MPH. Install Picoscope and record measurements. When “droaning vibration” occurs, prop shaft 1st order rises to 450nG. Remove rear prop shaft and drive vehicle again. Sensation is still present, but not as severe. Therefore did not swap prop shaft from known good vehicle. Call TAC- case XX-XXXXXXXXXX. Advised (due to Picosope readings) to measure backlash on each tooth of the rear ring gear. Found backlash to be between .011 and .001. Remove differential assembly (it was very difficult to pry from axle housing) and found side bearing races to have an “hourglass” wear pattern. Per TAC, NEC to replace axle housing, ring and pinion, and differential (may be causing ring gear run out concern). Attempted to obtain an assembly, but it is not available. Send out axle for setup due to pinion depth gauge not available in a timely manner. Reassemble rest of axle (axle bearings, ABS reluctors, seals, backing plates, axle shaft, cover). Install axle and road test. (total of 34 miles including diag road test). Sensation is gone.

Great update! Sounds like they are getting somewhere...slowly but surely. Hopefully you get a resolution. Please keep us updated. I am interested to know if the folks in Arlington about to build the 2016s in a few weeks know about this...or care?

 

Those of us following this thread from the beginning used to see GM reps chime in from time to time. They have gone completely quiet...Unlike the buffeting in some the 2015s.

Posted

Jasondenali, similar to your experience I am on my second 2015 Denali xl. I bought the first one March 2 2015 with a build date of 2-13-15 and got into the one I have now on June 3rd,with a build date mid March. The first one was fine until about 300 miles then the earaches, headaches and just feeling lousy everytime I drove it started. I had to wear ear plugs all the time in it. Went thru the whole service thing, pit5318,ring and pinion, to them changing the entire rear from rotor to rotor and nothing fixed it. After two months in service they took it back. The GM rep and my dealer were great and made the whole process of swapping the vehicles easy without any cost to me at all. Getting in touch with the GM Executive Office and starting a case also helped and then it went to the repurchase dept .I only have about 600 miles on the new one and so far no problems(fingers crossed). I wish anyone going thru this good luck.

Posted

Jasondenali, similar to your experience I am on my second 2015 Denali xl. I bought the first one March 2 2015 with a build date of 2-13-15 and got into the one I have now on June 3rd,with a build date mid March. The first one was fine until about 300 miles then the earaches, headaches and just feeling lousy everytime I drove it started. I had to wear ear plugs all the time in it. Went thru the whole service thing, pit5318,ring and pinion, to them changing the entire rear from rotor to rotor and nothing fixed it. After two months in service they took it back. The GM rep and my dealer were great and made the whole process of swapping the vehicles easy without any cost to me at all. Getting in touch with the GM Executive Office and starting a case also helped and then it went to the repurchase dept .I only have about 600 miles on the new one and so far no problems(fingers crossed). I wish anyone going thru this good luck.

Were the able to tell you what, if anything, is different about your most recent one?

Posted

Jasondenali, similar to your experience I am on my second 2015 Denali xl. I bought the first one March 2 2015 with a build date of 2-13-15 and got into the one I have now on June 3rd,with a build date mid March. The first one was fine until about 300 miles then the earaches, headaches and just feeling lousy everytime I drove it started. I had to wear ear plugs all the time in it. Went thru the whole service thing, pit5318,ring and pinion, to them changing the entire rear from rotor to rotor and nothing fixed it. After two months in service they took it back. The GM rep and my dealer were great and made the whole process of swapping the vehicles easy without any cost to me at all. Getting in touch with the GM Executive Office and starting a case also helped and then it went to the repurchase dept .I only have about 600 miles on the new one and so far no problems(fingers crossed). I wish anyone going thru this good luck.

You make me feel better that I am not the only one to give GM a second chance after such an awful first experience. I hope this one works great for you. I noticed the pressure and headaches around 250 miles with my second one...hope you are on the road to happiness with this one and it stays perfect. Please keep us posted.

Posted

Were the able to tell you what, if anything, is different about your most recent one?

There may not be anything structurally different, trucks like mine don't have any of these issues. To find anything different would force GM to admit they didn't conduct or report appropriate quality control of something wrong in the beginning.

 

 

Those of us following this thread from the beginning used to see GM reps chime in from time to time. They have gone completely quiet...Unlike the buffeting in some the 2015s.

Very good line Jason

 

 

It's commendable that independent dealers are doing what they can to mitigate the buffeting problem, but I can't see how replacing a non-defective part with the same part is going to solve the buffeting, just doesn't make sense to me? The tech did mention a couple of things, the "hourglass" wear pattern and the backlash, but didn't say if that was abnormal or not. Addressing these things with the same part will result with the another hourglass wear pattern and the same backlash?

Posted

Were the able to tell you what, if anything, is different about your most recent one?

[/The only thing they did was tell me your out of this one and pick out another one on the lot. The difference between the two is color,steel gray and chrome wheels. I wanted to wait for a 2016 but this was the only way they would do the swap. The dealer even gave me a letter saying if the new one has the same problems they will do it again. quote]

Posted

Jason Denali, thanks. I really like the vehicle and the way GM and my dealer handled the whole process. They also gave me a letter stating they will replace this new vehicle with another if I have the same issues. I know this doesn't define what the problems with these trucks are but I hope they find out soon.

Posted (edited)

Dealer sent me an email about a vehicle I inquired about. Seems like a lot of these might be on the used car lots now

 

 

 

Hello ,

Thank you for considering Sutliff Buick GMC Cadillac for your automotive needs. We know there are many dealers out there to choose from and appreciate being on your list. We are here to provide you with the information you need to make a decision that is right for you.

 

My name is Janelle Orris, I am an Internet Sales Assistant for the Sutliff Auto Group. I will be happy to assist you with your next vehicle purchase.

 

We recently received your request for information on a 2015 GMC Yukon. As of now, the vehicle you inquired about is still available for sale and ready to drive! I have attached the only picture I have at this time. This vehicle does not have a sunroof.

 

So you are aware, the prior owner said there was a vibration in the back end of this vehicle so GM had us rebuild the back and replace all the tires. The customer was still unhappy and GM gave them a trade assistance which got them into another Yukon Denali. You will need to sign a disclosure notice if you should buy this vehicle. Currently my Sales Manager is driving it and does not notice any vibration.

2015 GMC Yukon 4WD 4dr Denali

Yukon

Internet Price:

$59,994

Type: Used

VIN: 1GKS2CKJ4FR200995

Stock: 41706A

Style: 4WD Sport Utility Vehicles

Engine: 8 Cylinder Engine

Transmission: MYC ELECTRONIC 6-SPEED AUTOMAT

1 Click for Images Click for Details

 

Please let us know when you would be able to come in and take a closer look and/or test drive the Yukon. Our showroom hours are Monday through Friday 9:00 am to 8:00 PM and Saturday 9:00 AM to 5:00 PM.

 

We look forward to hearing from you.

 

Sincerely,

 

Janelle Orris

Internet Sales Assistant

 

Sutliff Buick GMC Cadillac

169 W. Aaron Drive, State College, PA 16803

Best # 1.877.895.7565

Next Best # 814.867.4444

www.sutliffbuick.com

 

 

 

This email was sent to: [email protected].

From: Sutliff Buick GMC Cadillac 169 West Aaron Drive State College, PA 16803

 

Update Preferences - to update your communication preferences.

Unsubscribe - to stop all future email communications [REF_V820559-497212_NO].

Edited by Cl Houn
Posted (edited)

So you are aware, the prior owner said there was a vibration in the back end of this vehicle so GM had us rebuild the back and replace all the tires. The customer was still unhappy and GM gave them a trade assistance which got them into another Yukon Denali. You will need to sign a disclosure notice if you should buy this vehicle. Currently my Sales Manager is driving it and does not notice any vibration.

 

One thing to buy this truck and it develop issues, doesn't make sense to buy a truck with known issues, especially being a member on this thread. Wouldn't have a leg to stand on if you wanted to take it in for vibration? This is red flag 101

 

Send this message to Janelle and see what she says. Something tells me she will say the dealership don't know anything about these trucks having a vibration problem, this is an isolated case.

Edited by The Zip
Posted

One thing to buy this truck and it develop issues, doesn't make sense to buy a truck with known issues, especially being a member on this thread. Wouldn't have a leg to stand on if you wanted to take it in for vibration? This is red flag 101

 

Send this message to Janelle and see what she says. Something tells me she will say the dealership don't know anything about these trucks having a vibration problem, this is an isolated case.

 

I wouldn't buy this after seeing this, but the disclosure seems like it's as is with the problem so no return. I appreciate them making the customer aware of this problem, most dealers problably won't say anything.

 

Another used car lot down the block from me jus got a Denali xl and I asked him about it and he says yes it has it too. Right away. Maybe the word is jus about officially out..would think the next step would be a resolution

 

But most of the used ones seem like they might be buy backs

Posted (edited)

***UPDATE***

I picked up my vehicle yesterday evening after having all of the work in my previous post completed. I am happy to report the buffeting is gone.

 

The reason for the issue seems to be pin pointed down to an incorrect backlash setting in the rear end. Some are set correctly and those with the issue are not. It seems there are 2 types of rear ends that were installed on these vehicles depending on availability at the time of the build.

 

The dealer opened mine up and found the issue. This incorrect setting caused abnormal wear on the ring and pinion as well as the side bearing races. These bearings did have a hourglass wear pattern due to the incorrect setting. They replaced the ring and pinion and making sure the backlash was set per the required specifications and also replaced the side bearing races.

 

I will report back if the buffeting returns, but for now, it is fixed.

Edited by cleanfreak
Posted (edited)

The tech did mention a couple of things, the "hourglass" wear pattern and the backlash, but didn't say if that was abnormal or not. Addressing these things with the same part will result with the another hourglass wear pattern and the same backlash?

 

 

***UPDATE***

I picked up my vehicle yesterday evening after having all of the work in my previous post completed. I am happy to report the buffeting is gone.

 

The dealer opened mine up and found the issue. This incorrect setting caused abnormal wear on the ring and pinion as well as the side bearing races. These bearings did have a hourglass wear pattern due to the incorrect setting. They replaced the ring and pinion and making sure the backlash was set per the required specifications and also replaced the side bearing races.

 

 

 

That's more of a positive answer "replacing the ring and pinion due to an abnormal setting on the backlash". This is the first time on this thread that something was replaced due to finding a problem. Put the vehicle through the test by going over bumps and at different speeds from 25 to 70. A lot of folks will be awaiting you next report. In the meantime, can you post a picture from your work invoice that pertains to the ring and pinion work?

Edited by The Zip
Posted

***UPDATE***

I picked up my vehicle yesterday evening after having all of the work in my previous post completed. I am happy to report the buffeting is gone.

 

The reason for the issue seems to be pin pointed down to an incorrect backlash setting in the rear end. Some are set correctly and those with the issue are not. It seems there are 2 types of rear ends that were installed on these vehicles depending on availability at the time of the build.

 

The dealer opened mine up and found the issue. This incorrect setting caused abnormal wear on the ring and pinion as well as the side bearing races. These bearings did have a hourglass wear pattern due to the incorrect setting. They replaced the ring and pinion and making sure the backlash was set per the required specifications and also replaced the side bearing races.

 

I will report back if the buffeting returns, but for now, it is fixed.

OK, now we are on to something! Thanks for the update, Cleanfreak! Like Zip said, this is the first time something was actually replaced and it fixed the problem. Let's hope it is indeed a permanent fix. Please, please, keep us posted with your results. You can help so many people with this issue by keeping us posted. No pressure, man. :)

 

I am most interested if the issue is gone at 42-43 mph. That is the speed most can pinpoint the problem without hesitation. Those were the speeds which both of my repurchased Denalis had the problem. If you decelerate at that speed range and the issue is gone, I think you will have solved the curse of the headaches, ear pressure, and buffeting. Please let me/us know your results at those speeds. Thanks again for being a team player!

Posted

That is good news, but the proof will be after several hundred miles of wear to make sure the problem does not recur.

Posted

I agree that this looks very promising. Even the folks on the pick-up thread are finally getting some reports of their vibration issue being solved with new rear ends. Not all, mind you. But of course, if the same defective parts or settings are used, then of course it won't solve the problem. My guess is that GM knows exactly what the issue with the pinion and ring gear are, but getting enough sets to replace all the problem pick-ups and SUVs, while tooling up to build the 2016's, is proving more than their crappy supply chain can deliver. So, they throw some parts from the "suspect" bin at the customer hoping it will either satisfy them or buy GM some time.

 

I do recall a report about 6 months ago on another website altogether that said they replaced the entire rear end assembly, housing and all, and the buffeting went away.

 

I also shared some of my research several month ago where I found several papers and a GM TSB that dealt with vehicle cabin boom as a result of pinion gear-mesh issues. So, this would be not big magical revelation if it truly is the root cause. The frustrating thing is that the gear tooth backlash was the very first thing my dealer checked. So, either they didn't check it correctly, or the specs they worked to are not correct. I suspect the latter.

 

Looking forward to my next conversation with the service department. Keep the reports coming in!

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