OmahaBen

Talked to my buddy that works at this dealer at today. Later Friday evening he got the update. The rear shocks have been replaced. They are going to put in new bearings and a ring and pinion in the rear differential. The GM engineer that has been overlooking my case has ordered 4 new tires for the my truck. We will see if any of these solve the issue. I really hope to get to the bottom of this because I have always been a GM guy and want to help others get their vibrations worked out too. I knew that buying the first year out of a new model could have issues but I did not expect this. Plus if I get a buy back I really don't want to go

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I wonder if the vehicle rolled off a transport or something like that. It is odd the front of the drive shaft twisted like that. Since it was bent on the front it seems to me that the power was applied from the rear. Like it rolled off and all of a sudden the wheels just stopped. Who knows I am no physics specialist.

I am surprised with the bearing preload not being correct that the backlash was consistant all the way around the ring gear.

I would like to document in one thread the solutions/fixes to vibration vs sifting and reading through 6000 posts. Please stay on topic. Please state Year 2014/2015 Make, Chevy or GMC Cab, Crew, Double, Single Box, 5.5, 6.5 or 8ft Engine V-6 5.3 or 6.2 Transmission 6 or 8 speed Rear Gear. 3.08, 3.23 3.42 or 3.73 Speeds the vibrations are present Solutions: 2014 GMC Sierra SLT Crew 6.5 Box 6.2L 6 Speed 3.73 70mph + Solution The things that have made mine better. Replaced one wheel, two LS2 20" Goodyears and Road Force Balance. Still not 100% fixed.

Update on the process. The second dealer that has had my truck checked the axles for runout on the axle ends, the backlash in rearend and the driveshaft for runout. None have any issues. They did check the backlash on every single tooth of the ring gear. However I did hear from the service advisor today. They did find that that preload on the pinion bearings is not correct. They said that they will probably end up rebuilding the rearend because there was almost no preload on the pinion bearings. Also both of my rear shocks are completely dead. We will see what happens from here... To be continued....

When it's all said and done I'll probably be told operating within spec and sent vibrating down the road. If that's the case this will be the last GM product I purchase. Keep pushing. They finally got approval on mine to pop the cover and check the backlash in my differential, they drove it and the pico meter and found it was out of spec. I did have to take it to another dealer. We will see what happens. I have been given 4 different trucks as loaners. All being GMC 1500 2015 models and 3 of the 4 vibrated worse than my 2014. One was smooth as can be. I can't see how GM can ignore this issue and keep truck customers. If you can feel a driveline vibration, pico meter or not something is wrong.

I am a GM guy all of my personal vehicles have been GM until this point. I dropped my truck off today with a different dealer, I know a service rep there and said they have fixed the issue in several. I thought I would give that a whirl before applying for a buy back. The loaner I got is a 2015 doublecab SLT truck and it vibrates worse than mine. Mine isn't horrible it just starts vibrating once you go over 70mph or so. With knowing all of the issues I am thinking about looking at other options vs buying another GM. I don't want to take a chance on a 2016 that may have the same issue. I hope I can come back and tell you the issue has been fixed. I really like the truck overall and the driveline. I don't think the other manufacturers have a better motor than the 6.2.

Today the local dealer swapped on a set of 17 or 18" wheels and tires from another truck. They are saying the vibration is within spec but the service manager does acknowledge there is still a vibration. Even with the other wheels and tires on he could feel it in the seat and steering wheel at the 75-80mph. The local dealer has been really helpful and is willing to do what is necessary to make me happy. We will see where this goes. Personally I would like to see this through and help as many people on here get this fixed up. While my vibration is not as bad as some there certainly is an issue with these trucks.

I have about 23K mile on my 2014 Sierra. It did not have an awful shake but a slight one. They have had my truck at least 6-7 times. GM even extended my warranty to 70,000 miles They got the vibration analyzer this summer and the pico meter at the beginning of August. Each time I get it back it gets a little better. However I think they have gotten it as far as they can because I got the "it is within spec" response from the service advisor today. I have been very patient but something is still up with this truck. I believe my problem is in the wheel/tire assemblies. They are going to allow me to try a different set of wheels and tires from another truck tomorrow. The plain fact of the matter is my old truck didn't vibrate at interstate speeds and this one shouldn't either. There is obviously a huge problem here as this post and all the videos on youtube. Here is my theory: The allowable runout of parts is too high. If each part say the wheels and tires, axles, driveshaft and all other rotating parts have the Maximum possible runout you are going to have issues. The allowable runout should be less and made tighter. I would suspect the vibration issues would go away. Hopefully this can be fixed for everyone. I can see a lot of diehard GM people switching to other brands because of this if they don't.

I have had my 2014 Sierra in the shop 5 times for the vibration issue. The first two times they didn't feel the issue so they thought they had it fixed by balancing the rear wheels. After taking the service manager and letting him drive it he could feel it get worse from 70mph to 80mph. They did a road force balance on the wheels and it made it a bit better. They have also replaced one 20" chrome GMC SLT wheel and 1 or 2 tires. Goodyear LS2s 20". (I say 1 - 2 because I didn't get a straight answer) They did find that their road force balance machine needed to be calibrated. They sent my 4 wheels off to another dealer in town and road force balance those. That made it much better. (almost acceptable but still annoying during long hauls) I drove the truck about 1000 miles and it still wasn't good enough. I told the service manager this and he said they had the vibration analyzer on order. It looks very similar to the one posted here. I actually got to see the tool. It basically allows you to put a sensor close to your rotating item. IE wheel, driveshaft or whatever. They use a magnetic base just like you would us with your dial indicator and that holds the sensor to the rotating part. If there is a vibration it assigns a number to that harmonic or vibration. They said when they connected my truck with the tool it measured an 8. After they were done it was below a 3. (below a 3-4 GM says that is acceptable because it isn't noticeable anymore while driving) I don't notice the vibration anymore. After they used this tool they got my vibration to go away. They stated it was still one of the wheel tire assemblies. They had the truck for about 5 days. I don't think there is anyway that it should have taken 5 times having this truck in to get the vibration to go away. I also feel that they are hiding the real issue because when I ask them which wheel they can't tell me. I told them when I first brought the truck in to do a road force balance on all 4 wheel/tire assemblies and after they talked they said they only did the rear tires at first. I have caught them lying or maybe they forget or make up stuff to the customer to get us to stop asking questions or go away. They did say they had to do a steps required by GM so they can get paid on the repairs. I have several other issues and if they get those fixed I will be pretty happy. A little discussed that it took so much time to get it squared away but I think when you get the first year of a new model you open yourself up to issues. My father always told me to never get the first year maybe 2 of a new body style so they can get the problems ironed out and I think he is correct. I have been flexible and very polite to the service team and manager. I have tried to make them my friends and I think that has helped. Hopefully others can get this solved to. I wish I knew if this was more than just tire/wheel issues. I feel that since they had it 5 days it could have been anything. That is enough time to replace the driveshaft, or do many other things such as rebuild or re setup the rear diff and many other items.

I talked to the local dealer and they said that the heated steering wheel can not be added. It will be really interested to see if this works for you guys. As I bet it can and will work.

I have a 2014 6.2 with 3.73 gear 4x4 Crew 6ft bed. I pull a 3500lb trailer between 70mph and 75mph and get 12-14 mpg average. Probably closer to 11-12 when going 75. A bit higher when going 65-70mph.

I had a similar issue with my 2014 Sierra 6.2 max twon3.73 1500 SLT Crew 6.5 Box. After having it to the dealer several times I took them for a ride and showed them the vibration. They said they had road force balanced the wheels and found one bad wheel. I then found out they only road forced balanced the rear wheels. Then after replacing those it did get better Once I brought the truck back the 3rd time the service manager drove the truck and showed him the issue. He said he felt it and while slight he said he would be unhappy about this if it was his truck. They kept balancing my wheels and found their road force balance machine was broken. They sent all 4 wheels and tires to another dealer and ended up replacing one tire. Most of the issue is gone but there is a slight feeling of a driveline vibration. They ordered the vibration analyzing tool and we are waiting on that. However if it can't be fixed more I has been improved by 80%. One more thing and I think it could be very close to perfect. The funny thing is that I told them to road force balance all the wheels and tires and they didn't listen or care. They do as they are instructed by GM because they only get paid for what GM approves. I will post again if they get the last vibration fixed completely. Hopefully they can. The service manager said the vibration is very common and service bulletins are out about this issue. Light duty trucks are where all the profits are for GM. This is my third GM truck and first brand new. They have to figure this out or they are done. Hopefully the issues can be found and everyone on this board can be made whole.

I have bought the older BFG KO version for my previous vehicle 2004 Silverado 3 times. 265/70R17 The first set Got 60,000 miles, second set got 65,000 miles and third set is unknown because I sold the truck with about 4000 miles on them. I have the junk Goodyear LS2s and they horrible, fine when it is dry, otherwise watch out or you will slide off the road. My plan is to get a second set of wheels and run the KO2 in the winter. I hope they last as long and have as good of traction as the KOs did. Good pick.

I agree with you that my issue isn't the same. Either way in my opinion these should not be vibrating at all. Especially since most paid $35-50K depending on options. My old 2004 Silverado never vibrated like this.

Purchased my truck (2014 Sierra 1500 4x4 6.2 Crew 6.5 Box.) about 1 month ago and didn't notice any vibration while on the test drive. I only drove the truck up to 70mph because the speed limit in the state where I bought it was 65mph. I drove the truck home at 400 miles at around 70mph and I did notice a slight vibration. kind of brushed it off at the time. Then I trailered some stuff 1000 miles and did one empty run 350 miles and the vibration was maddening at 75mph (Really Irritating to drive long periods) Once I drove the truck at 75 and 80 mph and backed it off to 65 you could still slightly feel the vibration because you pick up on the feel and notice it more. Then I found this forum and starting reading about vibration issues. Here is my evaluation of vibration feel of my truck before any work was done My scale is 1 being hardly noticeable to 10 the worst case possible) 65mph 1.0 out of 10 70mph 2.0 out of 10 75mph 3.0 out of 10 80mph 4.0 out of 10 Took to the dealer and did a road force balance and they found that one wheel was 8oz off and got GM to replace the tire and wheel. That made a huge difference. However I still feel a slight vibration at 75 to 80. Here is the vibration feel now: 65mph 0 out of 10 70mph 0 out of 10 75mph 1.25 out of 10 80mph 2 out of 10 I read on here someone said all vehicles have some vibration to a degree. While driving my wifes car I also started to notice vibrations in her car I never had noticed before while HWY driving. My Sierra has the 20" wheels and with this combo there is a lot less sidewall on the tire to soak up road feel. I think this increases the chance of feeling vibrations vs a 17" or 18" wheel. We are going to take the truck for Thanksgiving and that will get us to put 400 miles on it to see how it is over a long haul. The tires may be the culprit as well. They are (Goodyear LS2) cheapies and think that replacing them may solve the issue all together. I think that personally, I have focused so much about the vibration that I may feel one in the truck no matter what they do. Good luck to all. Ben