2015 YUKON NOISE IN CABIN

[cleanfreak]

Hope that response wasn't from a gm tech or sales person. Anyone else chane the rear end and drive shaft replaced ?

spdyprnt has replied to my PM with very good info on where he had the repair done and who to contact. I have forwarded the info to my service manager and I have a meeting scheduled with him on Saturday.

 

I believe this to be the fix to the issue. Thank you very much spdyprnt.

Edited June 4, 2015 by cleanfreak

[Cl Houn]

spdyprnt has replied to my PM with very good info on where he had the repair done and who to contact. I have forwarded the info to my service manager and I have a meeting scheduled with him on Saturday.

 

I believe this to be the fix to the issue. Thank you very much spdyprnt.

Good luck. Shed some light on this once you get it done. I'm itching for my truck

Thnx spdyprnt

[The Zip]

spdyprnt - you said the entire rear end/axle assembly and drive shaft was replaced and there is no more buffeting in your vehicle. What parts were broken, updated, recalled, or torqued? My point, if GM just replaced those parts just because they "guessed" it would fix the buffeting, then the problem should come back.

 

There was nothing wrong with the parts they replaced, they just put the same versions of the parts that were already on the truck?

 

Your service invoice may be key here. For the buffeting to have stopped, the invoice should say part x was replaced with a newer version of part x, or part x was torqued wrong, or part x was broken, or part x was recalled, etc, etc. If your invoice doesn't say that, I can't see this being a fix over the long haul. But then again, I don't work for GM.

 

What's written on your service invoice?

[Gmjunky]

Hold on there?

I washed my SUV and it fixed the problem, it goes faster too.

My SA apparently spoke with GM and they told him they are working on the 6th gear via software update.

Post the information please, who, where, how?

 

Thank you,

[Cl Houn]

Guess we'll find out when cleaners test it out

[Cl Houn]

spdyprnt - you said the entire rear end/axle assembly and drive shaft was replaced and there is no more buffeting in your vehicle. What parts were broken, updated, recalled, or torqued? My point, if GM just replaced those parts just because they "guessed" it would fix the buffeting, then the problem should come back.

 

There was nothing wrong with the parts they replaced, they just put the same versions of the parts that were already on the truck?

 

Your service invoice may be key here. For the buffeting to have stopped, the invoice should say part x was replaced with a newer version of part x, or part x was torqued wrong, or part x was broken, or part x was recalled, etc, etc. If your invoice doesn't say that, I can't see this being a fix over the long haul. But then again, I don't work for GM.

 

What's written on your service invoice?

I see your point. Good question Edited June 6, 2015 by Cl Houn

[Cl Houn]

In a rental now. Only had it an hour but only noticed a lil reverb type of sound on bumps so far

[The Zip]

Great start, now kick-up the "Pressure" a few notches. Tune the XM radio to a channel with very heavy bass then tell us how that reverb is feeling.

[FogDucker]

The bass is strong, especially with certain types of music, but I don't think it's related to 'the boom'. I've found that it's certain roads at certain speeds. There is one bridge near by where I can reproduce it every time at 60kph. Mild, but noticeable.

 

It really does sound like a double bass drum from a heavy metal band, just muffled.

 

--

Marc

[cleanfreak]

***A little update***

I took the vehicle this past Saturday to the dealership and rode again with the Service Manager. He was able to hear the buffeting noise (again) and he has contacted the engineer and they have agreed to proceed to troubleshoot the rear end. The first thing they will do is check the ring and pinion for wear and measure the backlash and check for wear on the teeth. They believe the possible issue is a faulty driveshaft not being fully compatible with the rear end, hence causing the issue of the ring and teeth to wear out prematurely.

 

I also had a few minor issues with the second row passenger head rest "rattling" within the seat causing an aweful noise and I have the infamous driver seat movement issue. He ordered all of the parts to repair said issues and they have arrived as of this morning.

 

I will be dropping the vehicle off on Monday to start all of the repairs and I will provide an update to what they find out.

 

During my research of finding the "head rest" noise, I also found the location of the "bass boom" you are referring to. In my vehicle it is actually located on the inside of the tailgate lid across the bottom (below the glass). With the vehicle sitting in the garage and off (no radio, no engine running) and the tailgate closed, I climbed in the back and took my fist and lightly 'banged' around trying to find the noise I was hearing from the headrest and inadvertantly stumbled upon this 'bass' sound. As I banged around on the tailgate lid, I was able to produce a very nice bass boom sound equivalent to two subwoofers.

 

My guess is, when you drive over certain roads, the "bumps" in the road reproduce what I found in this location. It is not an issue that bothers me, but if you find to be a major issue, I suggest looking in the tailgate area.

Edited June 12, 2015 by cleanfreak

[FogDucker]

My coworkers must be wondering why I was just crawling around in the back of my Yukon...

I think you're on to something cleanfreak! The plastic cover rests against a rubber seal. Maybe it's sealed in a way that it turns the lid into a woofer of sorts. Thumping around on the inside plastic yields a boom like sound, regardless if the glass is open.

I wonder what's involved in removing that plastic cover...

Edited June 12, 2015 by FogDucker

[cleanfreak]

you got it! I failed to take a pic. Mine was even more boom at the location in white attached.

 

[FogDucker]

you got it! I failed to take a pic. Mine was even more boom at the location in white attached.

 

Yes! I can reproduce it and it's more pronounced when thumping in the white area.

 

In removing the latch cover, I can see some sort of sound deadening material (white cloth like) on the other side.

 

 

Does anyone know how to remove the plastic cover? Or, maybe jamming g something along the rubber seam (orange arrows) is enough to prove this theory?

 

--

Marc

[Wrench589]

I've done a fair bit of thumping around, and is have found I can generate the "boom" in several places. Certain spots in the headliner. Opening and closing the rear doors, from the detents in the mechanism that holds the doors open, the floor in the back between the bucket seats, to name a few. Admitidly, I did not investigate the rear hatch area, but it seems to me that many places will excite whatever is booming. The challenge is to find what is actually responding to these various inputs to generate the boom. May be the rear hatch, but seems a stretch that an impact from the floor would be able to find a path to the rear hatch (which hangs down from the hinges). But, noise and vibration are complicated, and anything is possible.

 

Please report back if you do indeed isolate the source of the boom. That is definitely the key to the solution.

 

I sure have to wonder if the engineers at GM know what it is. My guess is that they do, but the cost to correct it is more that a few pennies, so GM will not do it. It's not a safety issue and sales have not been affected. There are tons of these on the roads and most people love them. My experience has been 4 out of 4 have the boom, so it is definitely in the design. I guess some people don't hear it. Let's face it, lots of people live next to noisy streets or train tracks, or airports. I guess we all have a different threshold of when a sound becomes "noise". So, GM can sit on the sidelines on this one.

 

But, if the owners figure it out, might be able to either insist on a fix from GM, or maybe come up with something to alleviate it. Never know.

 

Just a comment on the "white" stuff inside the hatch. That would be a sound absorbent, not a deadener. There is a difference. Absorbent will reduce noise via absorbing the sound wave energy and reducing he remaining SPL. (Literally turns it into heat inside the fibres). A deadener stops something from vibrating and generating noise in the first place. As well, certain deadener will also act as a barrier to noise transmission. The reason a point this out is the the white fabric material will do nothing to stop and vibrating of the hatch itself. It will merely absorb some of the sound generated but the outer hatch skin or more likely, it's there to absorb outside road and wind noise. GM has used virtually no sound deadener in these vehicles. Open up he cover to access he jack, on the left side. Pull that white sound absorbent up and loom at the top OD the wheel wells. They dab a few strands of deadener on there. What a joke! So who know how much the lack of sound deadener play a role in all this!

[cleanfreak]

***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 1^st 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.