The Zip

When my fold flat buttons are pressed, the front of the seat bottom moves up so when the back of the seat comes down it lays on an already angled bottom. The only way my seat will lay flat is if the seat bottom does not angle up, I don't think in my case a bolt is in the wrong position. I noticed this with all my seats on the 2nd and 3rd rows power bench.

When I bought my truck I also felt there was a lag in response from the gas pedal, until I adjusted the pedals. Once I found the sweet spot with my foot and the pedal I found out it wasn't the truck. Try adjusting the pedals when you hop in the truck just like you adjust the seat. I had another thought in mind when I mentioned 2nd row buckets, wasn't thinking about their practicality.

ajs800 - I am going to send you a private message, be looking out for it.

Hey, you put in work, good job. With the exception of being the extended version and 2nd row buckets, I think you have a good set-up. Do you have adjustable foot pedals?

Lockwasher - You are on the sidelines and appreciate the information provided by the owners affected with the issues and feel for the pain they are going through. I am an owner not on the sidelines and my posting won’t be defined whether or not my truck is broken. I too feel the pain, you had to have seen that in one of those 165 plus posts. But, shouldn’t it be encouraging to an owner and prospective owner like yourself that I have the same truck in theory and it does not experience the issues associated with this thread? Hey, point taken!

Don’t remember if any “owners” spoke about the GMC, but...

My truck really is like butter. Having my truck for 21 months (not 19 as stated above), I have never had any shaking, buffeting, vibration, or pressure. Now I did start another thread on pressure, but I think my issue was associated with my particular setup and the XM signal. My fix was as simple as not using those XM channels. Now there are standard size trucks having issues, but my truck is standard size, Chevy 2013 build cause it was on the road to the dealer in Jan 2014, 20 inch aluminum wheels, no roof rails, no sunroof, no under carriage engine debris protection (similar to a skid plate). I have all options of the LTZ except I have fixed side steps, no Magnetic Ride suspension, no rear entertainment, and no second row captains. Can these issues happen with my truck, yes, because Chevy/GMC/Cadillac all use the same GM platform. Now reverse what I said for "maximum" issues; XL size, non Chevy 2014 or later build, larger than 20 inch wheels may not be aluminum, roof rails, sunroof, undercarriage protection, moveable side steps, Magnetic Ride suspension, rear entertainment, second row captains. Not scientific but I'm not a GM engineer, the data on this thread (give or take a couple of items) leads to the GMC XL version to include Denali with Magnetic Ride suspension and 22 inch wheels as the truck with the most customer complaints associated with this thread. I will say though I have not heard “any” complaints from owners of the least expensive of the GM fullsize SUVs, the Tahoe LS. Go figure…

CI Houn – My comment seem hopeless, but I say all this because I have read every page and posted on the thread beginning at page one, so I am basing my comments on customer data. I had my Tahoe LT for about 19 months with no dealership downtime and it has always been and continue to drive like butter, so there “is” some hope.

I know your hopes are there will be a fix and it may be in 5 or so years when GM rolls out a new generation. But with this generation, a dealer is not going to be able to do anything with body, tranny, and engine mounts. Or length, cabin volume, and metal density. Until that time, the answer will be for dealers to make an extremely annoying level of issues to a less annoying level. A dealer may play with dynamat, tires, wheels, drivetrain, and maybe different suspension items to achieve a less annoying level, but you're going to be holding out for a long time waiting on a fix. A fix is way too costly, complicated, and restrictive for an independent dealer.

BoazE - post 113 from snuke1e is a good start

There is a fella on the PU forum that went from 22" chrome chrome wheels with a vibration in his truck to 22" aluminum wheels with Bridgestone tires that ended with no vibration in his truck. Don't know the manufacturer for the tire on his chrome wheel. Yet to be seen if the no vibration last but he says it currently drives like glass.

You went from 22 chrome vibration to 22 aluminum Bridgestone with no vibration. Do you remember the tire manufacturer of the 22 chromes?

Possibly, but you have to first make sure the tire wasn't faulty before it was put on the truck. Road force balancing a tire the first time is one thing, continually doing it a dealer has to look somewhere else. With all the posts of road force balancing, I'm not convinced this GM tire supplier provided a quality product. In order to move on, somebody needs to try a different brand tire. If a different brand tire decreases the shaking/vibration, then the next thing to look at would be to try a different brand wheel. If trying those two things and the shaking/vibration decreases over a long period of time, then the tires and/or wheels could probably be eliminated as a cause.

Reading multiple threads (PU/SUV) with tires needing road force balancing, that tells me GM received a bad product from the manufacturer of the tire or wheel. Road force balancing a new set of the same manufacturer's bad wheels or tires, guess what...

There are a lot of components in the driveline. The dealer should have found faulty parts, mating points off, parts not torqued to specs prior to making the claim of narrowing the issue to the driveline. If not, what led them to the driveline?

This is exactly what happens when you replace two tires with the same tires, a temporary fix. To eliminate the tires, you need to replace them with a different suppliers tires. Then if it continues to happen, you have to replace the wheel with a different manufacturers wheel. Once you do that you can eliminate the tire and wheel causing the vibration. But to replace them (if not a defect) with the same tire, expect to remain at square 1.

As a customer, don't need a picoscope to tell me about a vibration. Ok, the dealer determine there is a vibration, what's next. Still don't know the cause to come with a solution to stop it?

Being on the thread since page 1 and reading every page, I have also come to the same conclusion as your dealer on the standard size being "less" prone to the issues. I made a post on here somewhere that talked about it. To answer your last question, yes. If you were near California Central Coast I would take you for a spin, my truck doesn't have any issues associated with this thread (buffeting, pressure, shaking, vibration). But I do believe all these trucks are in theory the same, it's just some things (length, interior volume, tire, wheels, engine/body mounting points, etc) that determine whether a customer experience the issue.

Maybe I'm not understanding what you mean by openings, but went outside and looked before I made that post, no vents at least on the Chevys. No matter, air vents are designed to cool an engine or release heat from the engine bay, if enough air got past the block I don't think it would result in buffeting in the cabin. But I won't discount it cause at this point all customers and dealers are just guessing. However, I don't believe the manufacturer is completely clueless of what's going on, I think they are hoping a bandaid will work until the Gen 5 hits the street. A bandaid will not work, if there is nothing wrong with the part they are replacing by using the exact same part, the result shouldn't change anything.

Kind of not tracking with your post. The only opening in the front of my truck that allows air to circulate is the honeycomb grill, no other opening and the truck does not buffet. There is no cutout unless you happen to have tow hooks That was Gen 3, the opening in the bumper was for exposed tow hooks and an opening for circular fog lights, don't think the engineers intended those openings for air flow.

Man, there are some nice cars on this list. If it wasn’t for all the safety enhancements, you may be better off keeping what you have. But the fullsize SUV problems doesn’t surprise me, it’s been talked about this thread for close to 2 years. Although the Yukon and Tahoe mention things I’ll have to keep my eyes on, the XL versions and the Escalade mention engine and driveline vibration. This should be where dealers focus their attention when complaints come in about shaking and vibration.

You are right, the 4 yr piece should have been left off my post, you were talking about something else (deleted it). I do agree with you though, 4 yrs is a pretty long run on bad parts.

Unless the part has been modified or specs adjusted, GM is just changing out parts. If the time comes to settle with the customer, GM is filling the blocks by attempting to rectify a repeat issue. People change out parts all the time, because they were broken or it's a different performing part. If a part is not defective or out of specs, you can’t expect it to perform differently just by changing it out? A fix with these trucks is not a singular issue (although some customers may see the issue temporarily diminish somewhat), it has to be a combination with different size wheels, different tires, reinforced mounts, different exhaust, etc. If dealers don't or can't perform the combination, then when the warranty expires and folks begin to modify or there is a new gen with different parts, is when the customer will see a fix. Maybe around 2019?

These trucks have an element of noise (larger engines, thinner metals, bigger wheels) and pressure (buttoned-up jelly tight compared to gen 2 and 3) that I believe is managed together, get rid of one and the other is unbearable. GM has been in the truck business too long not to know this, so the only thing to do would be to manage it. Gen 2 and 3 didn't have the noise or pressure (I actually owned 2, 3 and 4 at the same time), so with GM knowing about the increased noise and pressure in the new gen 4, what could they incorporate to manage it?

May very well have something to do with the torque converter, but early in the thread there are/were trucks that had interior roof crossbars separating from the roof. Fixing the crossbars independently didn't do anything, but you can't definitively rule that out as an agitator.