Wheelguy

Thanks!

Got the Ultra Flex installed this evening. Didn’t have to remove the assist handle since I slid the LED light bar on the rail first like I mentioned earlier. Ended up looking almost exactly like your pic as far as bracket & light bar locations. Pretty pleased with it but will have to see how the weather strips behave after a couple of weeks in the sun. Will double check alignment as well - got it close enough for now. Thanks again for the info & pic - made things much simpler once my dumb a$$ figured out exactly where the brackets fit into the rail. A bird crapped on it not 2 hours after I was done ?

I've watched several install videos for 2019 GM trucks - none had the assist handle which figures? I may be able to slide the included light onto the rail first and not have to take off the assist handle at all. That I can think of, that should be the only thing which would get in the way of the assist handle based on the install videos that I watched. The clamp in that area can be installed without removing the handle as well. I'll get it figured out - thanks for the additional info & especially the pic!

Ugh is right. Sorry for the bad luck.

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Thanks a bunch for the detailed info & hopefully pics.

Thanks for the info - appreciate it. If you get a chance before this evening, take some pics with the tailgate down near the handle & post them. Just interested where the clamp near the tailgate will go.

Reading UncleDave's responses, the thread below comes to mind. Hard to say because everyone has a little different way of describing sounds. I had a loaner that did it - sounded like a ting ting ting (very small rocks pining off of metal) and would go away when pressing the 4WD button. There's a video showing an owner grabbing his bell housing and moving the shaft enough to make a noise. Seems to be a fix for it recently. Only affects certain front axle RPO codes (SU4 I believe).

I just saw that you have the 6 speed tranny - nevermind. My previous truck had the 5.3/8 speed which I traded for my 2019 Denali & I seem to recall hearing it shift on occasion - a faint clink if I had the windows down & driving near retaining walls or heavily wooded areas (where sound could bounce back towards truck). If the dealer can hear the sound, I'd ask them to throw chassis ears on it to try & find from where it's coming if they don't do it on their own.

Turns off the self-destruct pretests. ?

Anyone? Thanks!

Is the sound occurring when the transmission is downshifting - meaning does the sound coincide with any feeling of downshifting?

Does the Undercover Ultra Flex rail clear the folding assist handle in the bed of the Sierras with MultiPro tailgate? Would appreciate anyone that has one posting some pics with the tailgate down showing their rail clamp location along the driver side close to the tailgate and around the assist handle.

I understand. My dealership is pretty good about honoring the bulletins. It should mention the specific axle RPO (SU4) and for my dealer that would probably be enough for them to fix it. I would think the play in it alone would be enough.

If you’re not hearing anything then I don’t see why you wouldn’t at least wait until some of the other guys here report back that are going forward with the repair to make sure this is going to do it. I doubt waiting 2-3 weeks is going to take that much more away from the longevity than your mileage already might have. I hope that makes some sort of sense, in addition to what was pointed out about the techs getting familiar with the repairs. Just think about what all has been done with the clunking on the 8 speed tranny up to this point & GM is basically still playing a guessing game (or just plain playing dumb) with all that crap.

Mine does the same thing at start up after sitting - maybe longer than a couple of hours for me, but I haven't driven the truck for more than 2k miles yet. I have no clue if the two noises are related or not. All I know is that the dealer focused on the chirping sound while driving with light load on the engine and they had the chassis ears on the PCV pipe which led them to the PIP document I attached above. I was afraid of the "no fix" situation when I took it in....seem to be pretty rampant with the past 2 generations. What's ironic is that the loaner I'm driving is exhibiting the jingle jingle noise that disappears in 4WD.

Thanks Jaymz. Also, FWIW, I ended up emailing GM ([email protected]) & got my truck's build sheet. Mine was built on 6/19/2019 at Plant Z (Ft. Wayne plant - based on sticker on door jamb). Wanted to make sure I wasn't mistaking this noise for the one in the jingle jingle thread (goes away when in 4WD) .

My dealer's service advisor just texted me this morning and told me they put chassis ears on my truck and found the noise to be coming from a PCV. He referenced PIP5587 for which there isn't currently a fix. ? The PIP is attached below. PIP5587.pdf

?

Is this an anti-drool mod for the doggy?

So, took mine into the dealer the morning of 7/22 for a noise coming out of the seat vent fans (sounded like a bad fan bearing) and the chirping noise while driving at highway speeds with a light load on the engine. Service advisor has the shop manager go for a ride along so he can hear this chirping. We’re 5 miles or so into the ride along and he informs me his ears "aren’t the best" and he could never hear it. So I was just preparing for the worst in that i’d get the truck back with the big "could not duplicate". Fast forward to today and service advisor informs me the seat is fixed and they have been able to duplicate the chirp. Bad news is they don’t yet have a clue what’s causing it yet. Hope to get some more info from BeardBros (Jaymz) soon as well as my dealer.

Wow, you put a lot of effort into being more or less a dick. Sorry but, my crystal ball was in the shop, ace. Hope you get the sound you’re after.

Do you mean a build date of Nov 2018? ? Also, for what it's worth, I'm sorry you and others are having to go through all this crap. Unfortunately, I feel this is just a sign of things to come unless those making the big bucks wise up a bit and start making better decisions.

The design of that crossover pipe is absolutely nothing with which you should be concerned to the point you start removing stock tubing in favor of round tubes. Pipes are formed in specific shapes for good reasons - typically for either access (getting a tool to a fastener behind a pipe) or clearance. The simplest form of a pipe is round and straight - they don't deviate from that shape for sh!ts & giggles. Once the emission gasses pass through the converters, it's all about acoustics (sound) and volume (inside the tubes, collector, adaptive valves, muffler and any resonators, etc.). The volume in that area of the crossover pipe is pretty much the same as the round tube portion would be. When making pipes with these types of features and using the cheaper manufacturing methods for high volumes (quantity), material is typically moved around, not removed or reduced (or that is at least the goal) during the forming process. There are GM requirements for clearing both vehicle undercarriage, surrounding components as well as ground clearance. That's what GM ends up with given those requirements. The previous generation (K2XX) crossover pipe was also formed in a similar fashion but has a different cross sectional shape in that general area. The design of that area of the crossover pipe takes into consideration the starting tube diameter/circumference, so putting a round tube in there will change nothing other than possibly start causing interference which can lead to undesirable noises or taking damage under certain conditions. The entire system is tested both virtually (simulated on a computer using 3D models) and physically literally years before these trucks are built. The entire exhaust system performs the way GM desires it to perform, even with that flattened tubing. If there were any deviations from expected flow behavior, there is absolutely no way GM would allow those pipes on production intent vehicles and the supplier wouldn't be too keen on spending money on tooling to produce parts that ended up being a detriment somehow (of course, that all depends on how GM desires the system functions as a whole, too). However weird anything with the exhaust systems look, there's usually a very good reason GM didn't want that pipe to be round on either side or have a bash here or there. They don't make manufacturing a pipe more difficult, time consuming and costly just for looks or their own amusement. That costs GM money. The suppliers of the exhaust systems don't deform, flatten, bash, etc. tubing for looks or wasting machine production time either - that stuff costs money and they want it out of the plant as soon as possible in terms of processing time. But hey, it's your time and money you're wasting and it's your truck - you do what you want with it. Finally, I wouldn't waste my time responding to any of this if I didn't have intimate and first hand knowledge about the above, whatever that may be worth to you.

I agree 100%. I wonder how bad the carbon fiber beds are going to be with this? My 2019 Denali isn't the greatest (22" wheels/ stock 50 aspect ratio tires) and the loaner I'm currently driving (2019 2.7L SLE 4X4 without Multipro tailgate, smaller wheels & larger aspect ratio tires) is just about as bad. Can't believe how much lighter the normal tailgate is compared to the Multipro.