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Posted

Been there done that... Dealer replaced everything rear of my tranny..(3 driveshafts, 3 of the 4 tires were replaced, tires off another truck and diff rim size, rear end, engine shims and forgive me if I forgot anything... After they replaced the rear end and nothing changed, I knew my issue was most likely the transmission or torque converter... They "bought back" my truck and gave me 5 k trade in assistance towards the neg equity. My first truck was a 5.3, 4x4, 3.42, crew cab short box w 7k miles on it. The dealer offered me a free upgrade to an LTZ if I decided to purchase another Chevy. I gave them another shot and this one has been nothing but smooth for 17k now.

congrats, thats awesome, nice to see a dealer care more about the customer than the bottom line. hows the AFM vibe on that one? the loaner Tahoe I currently have is nearly unnoticeable... think I've only felt it shake once or twice and it was barely noticeable... unlike my truck

Posted

I have a 2015 Z71 4x4 CC Sierra SLT 3.42 rear end that started vibrating at about 2k miles. It has Rancho quick lift rs9000 struts on the front and rs9000s in the rear. Aftermarket wheels and toyo at II tires. After reading all the forums this is what I have done thus far trying to track down the issue in hopes of finding something that could solve the problem and possibly help others get theirs fixed as well. I used an app on my phone to use the internal accelerometer to find the resonance frequencies it vibrates at. Got a spike at 13, 26 and 39 hz at 72 mph. 13 hz is a first order vibration that matches tire speed directly, 26 and 39 hz are second and third order "vehicle speed" vibrations that could also be tire related. Had the tires road forced and 0 gram balanced 4 times. The 13 and 26 hz vibrations went away but the 39hz still remains unchanged. Could be a third order tire problem that is usually unfixable without replacing the tire. So I swapped the after markets for the factory wheels and tires. 39 hz vibration still there. Then I tried every combination of after market and factory. Took the better part of the weekend testing everything. 2 factories on the front, 2 after markets on the rear then cycled each wheel to each corner. The odds of every wheel and tire having a third order vibration is extremely unlikely which I think rules them out as the vibration source. Next step checked radial and lateral runout at all 4 corners. No smoking guns there either. Truck still vibrates from 70 - 75 mph. Tried re-settling the body mounts as posted here, no dice there either. Next step is to road force and 0 gram balance the factory wheel and tires and see if that changes anything. If not, I'm going to put the factory shocks and struts back on and test again not hopeful this will fix anything either.

 

After reading this forum and numerous others on this issue and the problem occouring in all cab configurations in both 2 and 4wd my suspicion is that the problem is the rear end, likely a bad ring gear. The ring gear spins at the same speed as the tires, a warped ring gear or bad spots in the tooth cut furing mfg. or heat treating could cause a 3rd order vehicle speed vibration. I did some research and found out the 9.5 inch rear end in the K2XX platform is a new design, and uses different internal parts from the 2013 and older 9.5 rear ends. Even though this rear end has been out for 2 years there are no after market gear sets available for it. Is this a possible known design flaw and things may be changed so no one wants to invest in tooling???? Rebuilding a rear end with the only parts available from the same company that made the original garbage parts doesn't give me a warm fuzzy but may be the only avenue to try and solve this problem.

 

The only other thought I have on the issue is a tolerance stack issue. Multiple items rotating at tire speed (hubs, axle shafts, rotors all technically within tolerance individually but when combined to form a rotating system cause just enough imbalance to make the truck vibrate and these new lighter stiffer frames transmit the vibrations right into the cab. testing this theory would require dynamically balancing all these parts which seems unreasonable. I'm trying to arm myself with enough data to avoid multiple trips to the dealer where they just rf balance the tires over and over before actually looking at the rear end or other drive train components as the source. I won't accept "normal operation" or "they all do it" out of a $55k truck.

Outstanding job with troubleshooting this problem we are having. If you are looking for a new ring and pinion set checkout

http://www.ringpinion.com/b2c/DiffList.aspx?SearchMode=Cat&CatID=35&MakeID=32&ModelID=456&Side=Rear&DriveType=4WD

 

I have used the Yukon gear set in both my front and rear diffs on a rock crawler I built. Hope this helps..

  • Like 1
Posted

No AFM vibration that I can feel but I've been driving around in M5. I tried this with my first truck and had the vibration even in M5. I really wish all of you the best of luck and hope either GM or your local dealers do you right...

Posted

It sincerely hurts me to see so many more new people with the vibration issue :fume:

 

Sadly, 97SierraSLT just might be right :sigh:

 

" I would not put it past GM to closely monitor this 340 page thread and just wait patiently for the loyal GM truck owners to correctly diagnose the root causes(s) of these vibration issues themselves "

 

Since the fall of 2013 GM has skated by on this and what's to stop them ?

 

@ 75mph I considered mine a Safety Issue, Yes it was that bad shorty after I made that statement the procedure

except for the actual check went a bit quicker.

So how do you like your Ram!? :) if you read a few pages back my experience is going sort of the way yours did except for I've had to drive mine through out this process and now have 20k miles on mine. Seeing as your dealership was always on your side and did what they could for your problem, how did that affect your buy back process? Just wondering because we just finished the final repair attempt with no improvement and are waiting on a GM rep to call us. Just curious to know if this will be a tad bit easier because my dealership is with me 100%. Glad to see someone from a while ago is still hanging around!

Posted

Been there done that... Dealer replaced everything rear of my tranny..(3 driveshafts, 3 of the 4 tires were replaced, tires off another truck and diff rim size, rear end, engine shims and forgive me if I forgot anything... After they replaced the rear end and nothing changed, I knew my issue was most likely the transmission or torque converter... They "bought back" my truck and gave me 5 k trade in assistance towards the neg equity. My first truck was a 5.3, 4x4, 3.42, crew cab short box w 7k miles on it. The dealer offered me a free upgrade to an LTZ if I decided to purchase another Chevy. I gave them another shot and this one has been nothing but smooth for 17k now.

You give us hope that we may find one that is "as smooth as glass" as we've heard other people say!

Posted

I've been wondering if anyone has put a confirmed "vibrator" on a stationary dyno,get it up to speed(70-75) and see if they can replicate the vibe without having to go on the highway.Would be smooth/consistant ride,unlike highway where little bumps can set it off,Seems like this method could narrow down the possibilities.If it still vibes on dyno,that would eliminate anything up front (Tires,wheels,Smooth Road Shake from the new electric power steering,suspension,aerodynamics) narrow it down to the rear tires/wheels,driveshaft,rearend gears/axles,transmission.....Still chuckle about the guy who was told it shakes because he put running boards on.

I was thinking the same thing but wheel dynos aren't plentiful or cheap unfortunately. I've thought about building some substantial jack stands to put under the rear end and run it with and without tires without worrying about it falling off some standard jack stands and driving through my house or the neighbors to see if the vibe remains. I think the jack stands might restrict the axle from moving if that is the problem though.

Posted

Outstanding job with troubleshooting this problem we are having. If you are looking for a new ring and pinion set checkout

http://www.ringpinion.com/b2c/DiffList.aspx?SearchMode=Cat&CatID=35&MakeID=32&ModelID=456&Side=Rear&DriveType=4WD

 

I have used the Yukon gear set in both my front and rear diffs on a rock crawler I built. Hope this helps..

Thanks, I've been checking Yukons website regularly waiting for them to release gear sets for these new rear ends. Right now the only option is to use a gear set for the old 9.5 along with all new bearings and adapters and spacers to get everything to fit up right.

Posted

Don't waste your money on paying out of pocket for rear end fixes. Take it to the dealer and explain the problem. I had my either rear axle assembly replaced and it fixed some lower speed vibes and the 50mph steering wheel vibe a lot of people feel when they are slowing down from highway speeds. They do have rear axle assemblies available with proper ring/pinion gear setups.

 

I've spoken with internal GM sources and they are well aware of the vibe problems. Multiple suppliers provided multiple parts that were out of spec, creating this terrible vibration nightmare that is nearly impossible to diagnose and even harder to fix. Tires/prop shafts/gears/etc....all out of spec, creating multiple vibes at multiple speeds.

 

I'm not surprised GM hasn't issued a recall...as there are plenty of people that don't notice, or ignore the vibrations on their truck. I personally have 2 friends that owned these trucks for over a year until I pointed out the problems...now they too are seeking resolution via BBB.

 

I am on my second truck now. I spent weeks test driving over 12 trucks. I thought I finally found one that was good, as it felt very smooth during the 20 mile test drive I put it through. I was wrong. It has the same lateral shake at highway speeds, plus the 50mph steering wheel vibration due to a bad rear axle assembly (ring/pinion backlash out of spec). I have just over 1000 miles on this second truck, and will be starting my journey through dealer visits and then onto the BBB very soon.

Posted

Don't waste your money on paying out of pocket for rear end fixes. Take it to the dealer and explain the problem. I had my either rear axle assembly replaced and it fixed some lower speed vibes and the 50mph steering wheel vibe a lot of people feel when they are slowing down from highway speeds. They do have rear axle assemblies available with proper ring/pinion gear setups.

 

I've spoken with internal GM sources and they are well aware of the vibe problems. Multiple suppliers provided multiple parts that were out of spec, creating this terrible vibration nightmare that is nearly impossible to diagnose and even harder to fix. Tires/prop shafts/gears/etc....all out of spec, creating multiple vibes at multiple speeds.

 

I'm not surprised GM hasn't issued a recall...as there are plenty of people that don't notice, or ignore the vibrations on their truck. I personally have 2 friends that owned these trucks for over a year until I pointed out the problems...now they too are seeking resolution via BBB.

 

I am on my second truck now. I spent weeks test driving over 12 trucks. I thought I finally found one that was good, as it felt very smooth during the 20 mile test drive I put it through. I was wrong. It has the same lateral shake at highway speeds, plus the 50mph steering wheel vibration due to a bad rear axle assembly (ring/pinion backlash out of spec). I have just over 1000 miles on this second truck, and will be starting my journey through dealer visits and then onto the BBB very soon.

The BBB is an absolute joke, forget them all together and start with the Attorney General. BBB is on the Business's side not the consumer. If you go in and read reviews about companies, it will show the absolute worst reviews you can give as positive, even when the review says they wound neither re hire nor recommend said business. The Attorney General's office will provide voluntary mediation, or you can go the lemon law route and use an attorney to push them. I personally would not waste my time with the BBB

Posted (edited)

Just an odd question, has anyone taken into account the towing package gear ratios? on my old 2014 Silverado 1500 "Yes this thing drove me nuts" it had 3.42 on a 2wd 5.3 6sp auto.

 

shook like crazy even after replacing the driveshaft and front pinon.

 

My new one has odd shakes from time to time "traded in the 2014" for a 2015 Silverado 1500, 2wd 5.3 6sp auto 3.42 but nothing like the old one and I can live with them.

 

Can it be something with the way they installed the towing package?

Edited by scooter484
Posted

Just an odd question, has anyone taken into account the towing package gear ratios? on my old 2014 Silverado 1500 "Yes this thing drove me nuts" it had 3.42 on a 2wd 5.3 6sp auto.

 

shook like crazy even after replacing the driveshaft and front pinon.

 

My new one has odd shakes from time to time "traded in the 2014" for a 2015 Silverado 1500, 2wd 5.3 6sp auto 3.42 but nothing like the old one and I can live with them.

 

Can it be something with the way they installed the towing package?

People have been mentioning that rear ends have not been set up to spec (backlash is out of spec). That's the only thing different on a "tow package" is the gearing. I believe others have also had 3.42 gears and 3.08 gears both cause vibration
Posted

Has rear end issue been seen on both G80 locker and standard rear ends? Mine is G80 and, knock on wood, has had no vibration.

Posted

The BBB is an absolute joke, forget them all together and start with the Attorney General. BBB is on the Business's side not the consumer. If you go in and read reviews about companies, it will show the absolute worst reviews you can give as positive, even when the review says they wound neither re hire nor recommend said business. The Attorney General's office will provide voluntary mediation, or you can go the lemon law route and use an attorney to push them. I personally would not waste my time with the BBB

 

Perhaps you had a different experience, but I recently went through the whole process. Sure it took a couple months, but in the end I got full MSRP trade on a new truck. I drove my 2014 for over 12000 miles and didn't pay a dime for it. The BBB worked out great for me.

  • Like 1
Posted

So I did more testing in my truck yesterday before dropping it off at the dealer again, The highway was pretty free for a change and I was actually able to get up to 82MPH for the first time in about a month, and I did not have any SERIOUS vibe issues, just the light vibe I get at all speeds (no its not standard road imperfections) , It did continue to have a worse vibe/shake when going around a curve on the highway at speeds of about 45+ MPH. The AFM still sucks, Ironically they gave me a Tahoe for the loaner and I only noticed the AFM vibe once in it, all other times it was flawless (audience gasps here) and guess what else.... The radio actually works properly (wispers among crowd in shock). So when I dropped it off, I specifically requested that they examine the steering position control sensor (figured what the h*ll, maybe they will find something wrong with it and the "smooth road shake") I also specifically asked them to roadforce and re-balance the wheels (figured what the h*ll, maybe I'll get lucky and it will help). They looked up the Service Bulletin for the Radio and were surprised that I knew about it when they didn't (So I thank you all here, please take a bow), we already know that the software is up to date, but they are going to check again, and they said they would try to play around with the radio again to see if they can figure anything out, but I'm not holding my breath.

 

So when he read the TSB, he said that GM is blaming it on obstructions such as buildings and poor signal quality from the provider. I said "thats a load of sh*t, these stations have been around here for years, and I've never had issues with them before, even in my old 2007 with the stock Ford/Lincoln deck that I traded in for this" and he agreed with me.... further proof is the Tahoe, It has not issues picking up the same stations that my truck can't do.

 

He is supposed to call me this afternoon about anything they find, what they can/ are doing for it, and when I'll be able to get my truck back. I'll keep you all posted with any findings

 

So I got the call this afternoon, the GM rep drove my truck, says he got up to about 75 MPH and claims the only vibration he felt was on the AFM. because of this, the dealer did nothing. they didn't roadforce the wheels or inspect the steering position sensor like I specifically requested they do. no examination of the drive train even though they even said the vibration is the drive train.... go figure..... their resolution is to "keep the truck in M5 so it doesn't switch to V4 and shake on the switch and when in V4 at specific speeds" the GM rep called it "the nature of the beast" and "normal operation" I tested this, and there was still vibration...

 

as for the radio, he listened and heard everything I was complaining about with the muddy, muted, faded audio and says "per bulletin ETIN PI 1288B, radio is in normal operation" the software is up to date, and they won't do anything about it.

 

I told the service rep at my dealer that if this is how GM wants to handle this, I will have to contact my attorney and file a suit/ claim against GM. He said he agrees that "this should not be normal operation" and that he "would advocate for me with GM on the radio" I proceeded to tell him how I have a 13 year old A/V receiver in my half subterranean basement with a speaker wire antenna that is mounted to the main carrying beam in the center of my house that gets better reception than my truck when in and around Boston/ Cambridge where the signals are broadcast from. he said "he didn't know the GM radios were that bad"

 

I will say that in my 2 days with the Tahoe, I felt the AFM vibe only once, there was no other Vibe issues. similarly with the radio, I only heard it fade/ muddy once in the two days.

 

I have already called my attorney, and am waiting for a call back to discuss where to go from here. this was only my second repair attempt, but with GM stating that it is "normal operation" when it clearly shouldn't be, I don't know what the next step is.

 

Sorry I can't provide any answers to anyone, but this is what GM is saying as of now.

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