Olvim

I’ll see if I can get under there this weekends for some photos of the mounts.

Hey man, yes; my truck was made in Silao - completely stock, outside of the Michelin Defenders. With regard to “tightening”, the dealer did an alignment for me after I screamed at them when they changed my tires (I had to pay the difference from th Goodyear SRAs to the Michelins, so I damn sure wanted them to wear well) and found that there was some slack in the front suspension and my toe was out a bit from the factory. I’m not sure if that correction or the tire swap took care of my steering wheel vibrations, but I can definitively say that it is gone - I’ve had no vibrations in the wheel for almost a year, even through a tire rotation. Now, I will say this truck has a lot of steering feel/feedback over bumps and even slight road imperfections, but I no longer have the oscillating vibration in the wheel. I’ve not yet looked at my cab mounts, but will take a gander. My vibes in the seat/console are so random and seem to contain so many variables it’s hard to pinpoint. It doesn’t always vibrate. I’ve driven 400 miles without ANY vibration at ANY speed, and other times the moment I hit 81mph it shakes a little. Temperature Seems to be a factor, as does type of road surface. I can get up to 90 on a concrete highway and it’ll drive smooth as can be, and 5 miles down the road when it switches to asphalt it’ll shake a little (I don’t drive that fast - I’m talking just for testing. My common commuter speed is 75-80 with the flow of traffic). My only assumption there is vehicle stance, and wear tracks on the asphalt road, which obviously are much less likely on concrete. I considered lemon lawing the truck at first when the vibes were bad in the steering wheel, but since that’s been resolved I can’t say my truck vibes “excessively”. I am constantly looking for it now. It’s just disappointing that it does shake sometimes, even though I’d characterize it as “minor”. Over my time on this forum I’ve seen some folks post about the generally “weak” engineering of our fold down center console on the bench, and I’ve got to agree - that thing is like a tuning fork and with shake like mad even if I just hit a bump. As a result, I DO think some of what I see in my truck is just natural resonance. If I can get it out of the drivers seat 100% (again, it’s minor), I’ll be fully satisfied, even if the console shakes a little. I’ve put the folding console in the up position and there does not appear to be any vibes in the actual bench seat, so... I dunno. Your guess is as good as mine. At the time, I had incentives for not wanting to dump my truck - GM discount, rebates, and 0% interest to name a few. I saved about $15,000 on the vehicle all said and done, and being the son of a GM retiree, I know better than to buy in the first year of a new generation. Otherwise, the truck has been great. My 5.3L and the 6 speed trans have been flawless for me. Shifts smooth, has plenty of power. I’ve gotten 30 mpg on the highway over 50 miles before. Couldn’t be happier with the vehicle outside of the slight shimmy in my seat (I’m not defending GM regarding his issue, just giving my experience of the vehicle). However, my dealer sucks - won’t ever buy a car from them again. Truck had 8 dealer visits and something like 40 days in the shop over the first 6 months I owned it, later I found out that most of that time it just SAT in their lot. It wasn’t until I got in their asses and told them what I wanted done that I got results and my steering vibe got resolved, and even then they never looked at my pinion angles, U joints, or driveshaft. Discount tire found one of my tires to be out of balance by 5oz when I first got the Defenders installed by the dealer. 5oz?! That was the result WITH their hunter road force machine. I have ZERO trust in the techs at the dealership I bought my truck at. Even after asking for an experienced person to balance my tires, they have messed it up every single time. This doesn’t even mention that until the GM District Manager got involved, drove my truck, and felt he vibrations in the wheel, the dealership completely DENIED it even existed. On at least TWO occasions, I dropped my truck off only to pick it up later that day or the next day with them having done NOTHING and telling me “it’s fixed; good to go.” Things didn’t move until the DM and a GM Engineer showed up to pico my truck (for the record, it was a T1 tire vibe they detected). Expanding on that, I’ll also never buy another Goodyear product (took them 24 tires to find 4 in spec and it still vibed on them after), not to mention another issue I had with SRAs on another vehicle years back. I’ve always had good luck with Michelins and Coopers - I’ll stick with those going forward. Either way, I’m happy to help however I can. If you’ve got more questions, just let me know.

Hey guys, just checking in after a good 8 or 10 months or so since my last update. My truck (2018 Silverado Z71 1500 Crew Cab 5.3L 6 speed 3.42 gears with 18” wheels) now has approximately 16,000 miles and is close to vibration free. Back in January, I had the dealer retorque the entire front end among with a switch to Michelin Defender LTX M/S tires and that got rid of ALL of my steering wheel vibration. I now ride smooth as glass from 1-80mph. Between 81 and 83, I get some resonance that vibrates my bench seat center console that I can feel just a little in the drivers seat that comes and goes and seems to phase around corners, but that’s it - speed related only and is not affected by acceleration or RPMs. It also completely disappears in warm weather (75 degrees and higher or so). I’m going to have a road force balance done at my next rotation in approximately 2,000 miles to see if I can take care of that. Otherwise, the truck has been good. I am frustrated that it still seems so sensitive to RFV, but I suppose it might just be the nature of the beast. After scrounging the Internet over the past year and a half, I’ve found every make and model of trucks with posts about vibrations. I bought my truck In May of 2018. GM and my dealer eventually told me nothing was wrong with my truck, all was operating within spec, and that vibrations at 80+ mph aren’t something they can diagnose, flat out telling me they’d expect some at that speed due to smooth road shake and natural resonance (though they did work with my regarding the steering vibes up to 75 when my steering wheel was still shaking, since I argued Michigan has freeways with that as their posted speeds). I went so far as to have my private mechanic who I have used for 5+ years look it over and he confirmed all was tight, fit, and in good shape after a suspension/driveline inspection (he and his brother own the shop and both drive 2017/2018 Silverados). In short, my steering wheel is firm, solid, and not shaking anymore since January 2019. I’ve got no shakes or vibes up to 80mph, and I’m willing to bet at this point the remaining shake at 80+ is either tires (I didn’t have seat vibes with the factory Goodyear SRAs, but they vibed the shit out of my steering wheel) or inherent in the design and smooth road shake (I should mention asphalt is WAY more susceptible to set it off than concrete). Time will tell, but the vibration is so slight in the seat that I’m to the point I doubt I’ll do much more. None of my passengers have ever felt it in their seats, even after I’ve asked (though my wife admits she sees the center console Shake a little when I’m at 80+, notably when I’ve got a big water bottle or something in it), so maybe I’m just looking for it at this point. Anyway, hope you all have good luck with your trucks. I can’t say I’m 100% satisfied at this point, but I’m close. I rarely drive over 80mph, so the fact I get some vibes there rarely affects me, but does still bother me deep down. Every vehicle I’ve ever owned has had nuances I’ve disliked, this is just the first NEW vehicle I’ve ever had in my 32 years of life, so it’s disappointing to say the least.

I’ve read similar complaints from some folks who said they only lasted 30-40k miles, while others noted 70k+. But honestly, I paid for only a tire and a half out of the set of four (dealer ate the rest), so even if they wear quicker than I’d like, it still beats those shit SRAs. These tires don’t vibrate at all. If the Michelin’s let me down on treadwear, I’ll go back to Coopers afterward. My wife’s 2016 AWD Equinox has the OEM Michelin Latitudes on them, and they’ve been solid for 40k miles and look like there’s another 15ish or so left. So far, my only complaint is that I lost my white sidewall lettering from the Goodyear SRAs.

Bought a set of Michelin LTX Defenders today (stock 265/65 18s). Paid the difference to upgrade as I got tired of the Goodyear SRAs slipping all over in the snow and constantly changing balance. Also found out my toe alignment was out in the front and had that fixed under warranty, after I insisted the dealership check it. Vehicle drives nicer than it absolutely ever has in my year of ownership (2018 LT Z71 crew 4x4). I have slightly more road feel now due to stiffer side walls (I run at 36lbs cold all around), but the ride is SIGNIFICANTLY better over the Goodyears and there is no vibration at all anymore, even in my bench seat console. They all roadforced to 12lbs or less easily. Took it to 95 mph and it drove great. Couldn't be happier. Would've never considered the Michelin's had it not've been for this post (always had good luck with Cooper ATPs), so cheers to all of you who suggested them.

Luckily for me (and everyone on this forum), this post was a wealth of information. Everyone’s shared experiences, recommendations, and support were extremely helpful. I hope that everyone is able to get their issues resolved, and being courteous and patient is absolutely the best approach. I’ve been a GM customer my whole life (direct family employment ties) and while I don’t think that’ll change going forward, I will be more diligent and scroutinous about my purchases. I did months of research on the Silverado before I bought it and not once came across the vibration complaints (or this website) before I signed all the paperwork. Great community we have here, and I’m very thankful to have found it.

While I agree with you a lot of the blame should be on Goodyear, in my case, as it took TWENTY TWO tires ordered BY THE DEALER from THEIR tire distributor to get four within spec, my truck was nonetheless in the dealership shop for 48 days over NINE different visits with two GM Engineer appearances and work with a District Rep over the first eight months of ownership for what turned out to be.... BALANCING!?! Up until yesterday, they were using the cheap sticky weights, too - you know, the ones they cut to size/weight. They must’ve hired a new tire guy because the OEM weights are now back on my wheels, and my truck finally drives great (here’s hoping it STAYS that way). How this happened and went on this long is beyond me, but the blame is absolutely not solely on the tire manufactures. GM contracted with them to put these piece of shit Goodyear’s on their trucks. That’s their problem, not mine. And all the time I wasted dealing with this in a brand new vehicle is something I’ll never get back, along with all the scratches I have on my rims now from the movement of weights on NINE different occasions. I gave them plenty of chances to get it right (nicely and respectfully, I might add), only to be told “we don’t feel anything” and “the truck is operating as designed.” Bullshit. To me, this is absolutely unacceptable, from Goodyear’s manufacturing process, to GM’s lack of customer service, and my dealerships ridiculous hoops and awfully trained techs. I told the dealer at multiple intervals that if the tires were that bad, they should’ve upgraded me to Michelin’s or Coopers by now. I was told by the District Rep that was “legally impossible” due to the Tread Act and all the fallout from Firestone back in the day. After buying two cars from this dealer, I guarantee I won’t be returning ever again. Given my experience, I give props solely to the GM District Rep. He upfront admitted something was wrong with my truck when he drove it. Without his help, I’d still be dealing with this issue with the dealer’s service department, who he told me, did NOT believe me when I said there were vibrations. I wrote GM a letter about my experience that included his praise. The guy did his job, reimbursed me a monthly payment for having my truck for so long (34 days straight for one visit), and for now, my vibrations are resolved.

Had my first oil change and service today at 6900 miles. Turns out all four of my tires (which were just replaced in October, 2018 at the same dealership) were off balance again. This either speaks volumes to GM Tech abilities or to the incredible ability for the Goodyear SRAs to change drastically over less than 3,000 miles. I get that balance changes over time, especially with new tires, but this has been excessive. Smooth as glass on the highway up to 85, by the way. Drove around long enough to let them heat up to be sure I wasn’t being fooled. I thought the truck was smooth back in October. Today is a totally different experience. Drives better than my wife’s Equinox now. We’ll see if this sticks, or if in another 1000 miles the tires are all out of balance again. Quick reminder from my previous posts; I had a vibration in my steering wheel and sometimes the center console (bench seat) since purchase. The rear end, gas pedal, seats, and the cab as a whole have always been smooth. 2018 Chevy Silverado LT Z71 Crew Cab, 3.42

This mirrored my experience exactly. It was balancing all along, and after 7 trips to the dealer and over 40 days in the shop, a Hunter tech got mine right on the first try. My truck is smooth as glass now (2,000 miles and counting). The only thing I feel now is the road on the highway, a slight buzz/tingle in my hands anytime I’m going over 73. The Goodyear SRAs have something to do with that road feel, in my opinion. Mine seem to flatspot overnight in the cold weather here in Michigan and it takes about 10 miles for them to warm up and smooth out. A set of Michelin LTXs should alleviate that when I’m due for new treads, but I’m too cheap to drop $1,000 on tires on a truck with only 6,000 miles. Either way, in short, mine is WAY better now. I am convinced GM techs have no idea what they’re doing unless something throws a code and tells them exactly what the problem is.

This. If a Hunter tech can get my tires right in one try and GM couldn’t over 6 months and 8 visits to the shop, there’s a big problem there. That’s not to say the truck is still just way too sensitive (because it is), but it’s appalling that none of the techs that serviced my truck were able to use the machinery properly. The dealership mechanic industry seems to have developed into code diagnosis and that’s it. If it doesn’t throw a code, then there mustn’t be a problem and the customer is crazy.

I’m sure it is the truck. It seems super sensitive to everything. Mine being a 2018, it has had a few of the bugs worked out, but it’s still very sensitive. It’s been 1,000 miles since the Hunter tech got my tires right and it is still smooth as silk on the highway (again, I’ve never had the cabin/seat/floor shake - just the steering wheel). Its never drove as nice as it does now. I told my dealer and the DMA I worked with the same thing you mentioned - it’s ridiculous to have to do this process every time we swap out tires. That’s why I’ll be putting Michelins on mine when the Goodyears wear out. If it can ride as nice as it does on Goodyears right now, I’m sure it’ll be 100 times better on Michelins. Would’ve swapped right away, but I’m just too stubborn to accept paying for new tires on a brand new truck that came with... new tires already.

Wish I knew the answer, and I agree. I have, however, seen similar complaints from Dodge/Jeep, particularly on Wranglers (which is what I owned before this truck). My father in law’s old 2011 Ram 1500 had the shakes at one point and, guess what? It had Goodyear SRAs on it. For some people. It depends on the truck and the model year. Drive shafts have been the issue before, I’ve read articles on rear axle issues, or rack and pinion angles. I think the 2014 and 2015s had potential torque converter problems and trans flush bulletins. However, I believe MOST people experience shaking of the seats, floor, and cabin at multiple speeds. My shake was always just in the steering wheel at 70mph +, so I might be in the minority. I’ve got a 2018 Silverado LT Z71 Crew Cab 5.3L V8 6-Speed with 3.42 rear axle. Based on this post alone, I won’t be putting any other tire on my truck (after the Goodyear’s wear out) other than Michelin Defender LTX M/S2s, as I do probably 90% paved road driving unless we go up north and hit some trails in the summer/fall (still would consider Cooper Discoveries, though, as well - always had good luck with them). However, I bought this vehicle to accommodate my young family and I intend to hold onto it for 10-12 years, so my position may be different than others. At 31, it’s my first “new” vehicle.

It took my dealership 6 months, 7 visits, and hands on training with a Hunter technician (the company that makes the Road Force Balance machines) to get my tires right. You might have better luck than I did with the dealer, but in all honesty it might be worth checking around. 4 Wheel Parts should stand behind their work, however. If they have a Hunter machine, I'd push them to do it for you. Most road force balancings cost around $100 for all four wheels/tires, but its only as good as the tech doing the job. If 4 Wheel Parts can't do it, I'd call around to some local tire shops and see if they can help you out. Unfortunately, its one of this things that are hit and miss, and you're not guaranteed to find a quality balance at a place like Discount Tire or Belle Tire (though you may - again, depends on the staff). Road force balancing, simply speaking, lines up heavy/light spots on your tires and wheels to minimize as much runout as possible and give you the smoothest ride available. It's measured in pounds, and from firsthand experience with my dealer (along with lots of other posts on this thread), we know the spec for the Goodyear Wrangler SRAs is 15lbs. I'd venture to assume that spec is the same across the OEM tire size, regardless of manufacturer, but a higher quality tire will definitely have less trouble. If you increased your tire size, you increased the amount of sidewall. The more sidewall, the better the tire will be at minimizing vibrations, meaning you might get away with 18lbs or something (just a guess - don't quote me) before you start feeling vibrations. Of course, going to load range C from a passenger OEM tire will make your ride a little stiffer, so you might feel more from that, too. Wish I could be more help. I was convinced there was a problem with my brand new truck for the longest time, but it eventually turned out (provided my ride stays how it is now) that the GM dealer techs just weren't using the Hunter machine properly. It took 17 Goodyear SRAs to get four that matched my rims in spec. Good luck. Let us know how it turns out.

Hey Mountaineers, This was actually the very first question I asked the DMA who worked on my truck, i.e., "What exactly do I do when it's time to replace tires?" He told me to get the OEM Goodyears again (which I won't be doing). I doubt your dealer will do much for you, since you had the tires replaced at 4 Wheel Parts. If you want them to take a gander at your driveline/suspension/driveshaft, save for your 5100s, then they might do that for you, but I doubt much else. Luckily, you know that if the truck didn't shake beforehand and you had no other work done, it's definitely the tires. You're going to need to get them road force balanced. The GM spec is 15lbs for each tire, though since you changed sizes too, that might give you a little bit of leeway. When it does come time for me to get new tires, I'm going to make sure the shop replacing them knows that I won't accept a tire that is higher than the spec I was told by GM. I know it won't be a fun conversation, but I'm not going to go through this again. In other news, since my dealer finally got mine road forced correctly (after 6 months), it's been about 500 miles of almost exclusive high driving (70-85pmh) and no vibes have returned for me as of yet. My truck is smoother than its ever been. I can drive it with one finger.

I fully agree with you. Not a snow ball’s chance in hell I put SRAs back on my truck again once these are burned. As as far as trust in the dealer techs, that was lost long ago. No reason an issue like this should’ve taken 7 visits and 44 days. For me, it was simply a matter of principle. I was not going to pay for a service that I shouldn’t need to do on a brand new vehicle. Of course, there’s always cost reward. Would’ve saved a lot of time had I just went out and got quality treads.

Hey guys, Wanted to stop back in and give an update on my truck. I got it back today after it spent another 9 days at the dealer. They still seemed stuck on tires even after I asked them to check hub/axle run out, drive shaft balance/run out, and rack and pinion angles. After I couldn’t get too many answers from my dealer, I kept my DMA’s cell phone number from my last visit and gave him a call - we had a good talk for about 30 minutes. The approach they were about to take was to get 4 pre-engineered factory tires from GM. Mine came with blackwall Goodyear Wrangler SRAs initially, but they were immediately replaced due to flat spots with whitewalls. The dealer and the DMA told me the tires from the factory were better quality than those from the supplier. I informed them I was fine with this approach, but I wanted to know what I was supposed to do when I did wind up needing new tires. I also expressed my concern that what I asked to be checked had not been over the previous week. At this point, the DMA leveled with me and said GM is well aware of this thread (I mentioned it specifically) and of the sensitivity issues of the K2 generation. He said the truck is like a giant tuning fork, and anything that is slightly out will set it off, especially in the 73mph range. He told me a ton of engineering has gone into the 2019s to alleviate these issues. He also told me that since this generations inception, he’s never seen hub/axle run out on a single Silverado he’s looked at since 2014, and he told me there have been hundreds. He said each vibes a little different, and that mine is actually quite smooth (of course, as a 2018 model I benefit from having all the TSB updates already handled at production). In short, he told me it’s been tires on EVERY single Silverado or Sierra he’s ever looked at. He also clarified my vibrations. I told you guys in my previous post that the dealer told me I had a T3 vibe at about 20mg. The DMA confirmed with me that the tech at the dealer put the receiver for the PICO scope in the REAR of the truck, when my vibes were in the steering wheel. When the DMA and GM engineer corrected the issue, placing the receiver on the steering wheel as per the instructions on there PICO scope and GM’s guidelines, they found I had a T1 vibe that would sometimes see spikes in T2. Due to this, two tires were replaced (previous visit). I thanked him for all the info and his help, and he committed to drive out and take my truck for a spin that same day (yesterday). About an hour after I talked to the DMA, the dealer called me and said that they had a tech from Hunter out to give training on the Road Force Balancer that day. They used my truck as the training vehicle. The tech from Hunter IMMEDIATELY found that all FOUR of my tires were improperly road force balanced and way out of spec (which IS 15lbs). Two were so bad they had to be replaced AGAIN (that brings my tire count up to 17). The Hunter tech apparently worked some magic and got my tires down at RF: 10lbs, LF: 15lbs, RR: 3lbs (amazing), and LR: 10lbs. He took the truck for a ride first and balanced them while warm. He also “massaged the bead” and did some other tricks to get a true reading. I picked up the truck this morning and drove 20 miles on the highway into work going the long way. I IMMEDIATELY noticed the difference. Still a few minor vibes over the first 5-8 miles, but totally disappeared once he tires heated up (truck sat outside in 30 degree weather last night at the dealer, so probably some flat spots). I have to drive to Detroit later this evening and will be able to get a better sense as to if this issue is resolved or not, but I can tell you guys that what I was feeling before has been eliminated THUS FAR. It is smooth as glass up to 85. In short, it seems it was tires and that GM knows they made the most sensitive truck on the market from 2014-2018. After seeing GMCJoe’s success, among others, with the dealer putting on Michelin’s, I asked my DMA to do the same for me (this is before I picked up my truck this morning). He told me there is a federal law (The Tread Act) that prohibits them from doing that and that GM can only put on tires engineered specifically for the vehicle at OEM specs. So for those of you who swindled Michelin’s, I applaud you - I couldn’t get them to budge. Anyway, seems to me that LOTS of people hit the nail on the head with this. GM Dealer techs CANNOT and DO NOT do a quality job of road force balancing tires. I am SO glad the Hunter tech was there to road force balance my trucks tires and that I just so happened to have it at the dealer when he showed up. I’ll report back once I’ve driven some more miles, but as of this morning, my vibrations seem to be resolved and it WAS tires afterall. P.S. - I asked the DMA what tire I should replace the Goodyear’s with once it comes time to avoid this BS again. He told me another set of Goodyear’s. I literally and audibly laughed on the phone. Hope you guys are making progress, and I hope this was my last dealer visit until I get my FIRST oil change. Total visits for resolution: 7 Total days at dealer: 44 End cause of vibes: SHIT tires and POOR GM techs that had no idea how to use the Hunter Machine

This is what I’ve most recently demanded from my dealer. They told me they “inspected” them on my last visit, but when I asked what the runout measurements were they couldn’t tell me, so I think someone just looked at it and stated, “yup, that’s an axle. It looks fine.” A senior advisor from GM Customer care called me yesterday. Told her my whole story. She flat out told me there wasn’t much she could do for me because my dealer is “trying to address the problem” and that her job just pertains to pushing the dealer to address it, getting a DMA involved, and sending notices to GM TAC, all of which have already been done in my case. She also freely told me that GM is aware of the vibe issues with the K2 platform (Silverados, Sierras, Suburbans, Tahoes, and Yukons) and that some vibes are to be expected (lol). Sounds petty, but I’ve been less than impressed with the GM service I’ve received. The dude that worked on my tires and wheels got them all mixed up and the sensors were matched to the wrong tire. To what someone else said about wearher and temperature affecting the vibes (steering wheel only for me), I fully agree. It’s 30-50 degrees here in Michigan and I am not feeling nearly as many vibes as I did during the summer. Anyway, I’ll keep you guys updated. Dropped my tuck off at the dealer again yesterday. It has 4,583 miles on it. No estimate on how long it’ll be this time (25 days last visit). GM offered to pay my monthly payment last month since they had my truck the whole time. It’s been over 30 days - I’ll give you guys one guess as to whether or not I’ve received that check.

Hey Guys, Longtime viewer (since purchasing), first time poster. Bought a new 2018 Chevy Silverado LT Z71 Crew Cab Short Box 5.3L V8 6-Speed 3.42 in May, 2018. Pretty much since purchase it has had vibration issues. Wanted to give you guys a bit of what I've experienced, which might be a little different than some of the other complaints, though definitely has severe similarities. My vibrations, specifically, are in the steering wheel only at any speeds 70mph or greater - outside of this range, the truck is smooth as glass (though I can feel literally every road disturbance resonate through the wheel). I was rather convinced starting out that it was simply an unbalanced or out of round tire. I have never experienced any seat, floor, pedal, or cabin vibes, nor have I had issues with the phasing boom. My center console (bench seat) does shake a little at around 42-45 mph and a little on the highway, but it doesn't bother me much and it is the only thing (other than the steering wheel) that shakes. I've tightened the bolts holding it down and it's significantly reduced the vibes (though also obviously made it harder to move up and down, though not a big deal at this time since I rarely utilize that seat). My truck's been to the dealer six times for this issue for a total of 32 days combined. I was initially told, when I finally convinced the dealership to perform a PICO, that I had a T3 vibe in the low 30hz range in the steering wheel. The initial set of tires on my truck were loaded with flat spots, and I've gone through three sets of Goodyear Wrangler SRAs on the 18in Z71 rims to date. Each time I brought the truck in, the vibes got better. First it was a bad dynamic balance, then it was a bad road force, then it was replacement of tires. As I continued to complain, since I was not satisfied with the truck I paid $39,000 for that drove worse than the 2005 Jeep Wrangler I traded in for it, a DMA was finally called in to drive my truck. He felt the vibration, and went around and around trying to identify the problem. He finally called in the engineers and I was informed that the PICO scope was installed incorrectly on the previous test and I actually had a T2 vibe in the mid 20s range with an amplitude of about 20mg. Afterward, all the tires on my truck were replaced until the wheels road forced out to 10lbs or less. It is my understanding from my dealer, though I've never seen it in writing, that the tire spec is 15lbs, but I was informed the engineers prefer to see it under 10lbs. They also did an engine mount procedure at the same time, unbolting them and moving the truck to be sure none were binding. When I got my truck back last month, I noticed that is about 90% vibration free, though it still occurs (with a MUCH lower amplitude, never spiking over 12mg - I was told by my dealer that 14mg is the "GM Spec"). The vibration I'm still getting happens only at times in which "something" comes into/out of phase. It's harmonic, happens typically in 2-3 second intervals every 2-3 seconds alternating until I make a turn that causes my wheels to spin at different speeds and move the harmony out of/into phase. I've noticed that if I drive for longer periods rather than short, it seems to diminish. I've also noticed it appears worse on blacktop than concrete, and that temperature or humidity seem to affect it (the hotter/more humid it is, the more likely I am to feel the vibe in the steering wheel). Of course, all of my service tickets state that the truck is operating within normal tolerances and that GM TAC has no further instructions to work on the truck. They state that the mechanic at the dealer "inspected" the driveshaft, drivetrain, and suspension and that all appeared normal. Now, the interesting part in all of this, and what also appears in writing on my most recent service ticket, is that during the diagnoses of my vibes, the dealership test drove another 2018 Silverado, observed no vibrations, and then took those 4 wheels and put them on my truck. Those wheel configurations were 20" rims with Continentals. After driving my truck with the wheels/tires from the other truck, the vibrations in my truck GOT WORSE. When I brought this up to the DMA I've been working with, he told me he still felt it was just a tire issue since "the Z71 suspension is more stiff". To be frank, I'm simply not accepting this as an answer. While the truck's vibes are "currently" 90% gone, I find it hard to believe that I can walk into a tire shop when it comes time and demand I get four new tires that road force out to 10lbs or less. Since GM sells Z71 configurations with 20" rims, I'm going to continue complaining until they 1.) check and provide me a printout of runout measurements of literally every driveline component, 2) check and provide me a printout of the driveshaft's balance numbers, 3) check and provide me a printout of the runout of the driveshaft itself, and 4) check and provide me a printout of the camber and castor of all the axles. While I have no intention of ever getting 20" rims on my truck, it seems fishy to me that GM would simply "mask" this problem with PRISTINE wheel road forces, send customers on their way, and not have a care in the world when 3-4 years go by and they have to buy tires and suddenly encounter a vibration again. I've obviously read a lot of this topic and freely admit that I think my Goodyear SRAs are an utterly shit tire and flat spot damn near over night, however, it seems odd to me that such nightly flat spots would last more than 5-10 miles. I've had issues with Wranglers before (on my old Wrangler, in fact) and have ALWAYS been much more satisfied with the quality of Coopers and Michelins. I'm not sure if sole steering wheel vibrations is classified as part of the "Chevy Shake", but I can tell you guys its annoying as hell. I drove 200 miles on Saturday in my truck and I felt the slight harmonic vibration for literally all of 12 seconds during the entire trip, but its enough for me to believe something still isn't right, knowing that the vibes in my truck got worse on well balanced 20" rims during the previous diagnoses. I'm not necessarily looking to file a lemon law case with this, but I'm also not ruling it out completely. I consider myself lucky to have found a 5.3L V8 and 6 Speed tranny that seem to be mating well together. I've had ZERO hard shifts, ZERO stutters, and ZERO lifter ticks thus far. While I don't consider myself to be fiercely brand loyal, my father was a GM employee for 31 years and I try to keep that in the family and support fellow American workers. My family has purchased 10+ GM vehicles in the past 20 years and this is the first problem I've ever encountered. I can tell my dealership is absolutely fed up with me and my truck, but I'm going to continue this until I get some real numbers and ideas as to what the hell is going on. I don't think my issue is in the rear end like some of the other shakers since I experience only vibes in the steering wheel, but I want to be sure I can take the runout measurements to a good mechanic and get some opinions as to what might be going on. As a side note, I've driven 5 loaner 2018 Silverados during this whole process. 2 of the 5 shook, but none in the steering wheel like mine - they all had visible cabin vibes in the seats, the floor, or the whole cabin. One had 20" wheels, the other had 18". Anyway, I've currently got an open case with GM Corporate, and I've called my dealer and advised what I want them to do. I'm waiting to hear back from the DMA. I've been MOSTLY patient and kind through this process, but will continue to push until its resolved. I know my case may seem minor to some of you, but I was hoping that by sharing you'd get a little more info. Please feel free to reply if you want further details from me.