Truckasaurus

Thanks, This was corrected with a software update some time ago, so it's not really an issue any longer. My primary motivation for going with the block heater wasn't for cold start, so much as it was so that i could have HEAT a lot faster upon cold start.... having the heated block yields a heated cabin a lot faster. Turns out it was a software glitch that if the block heater was used in temperatures greater than some threshhold, the computer would think the engine was overheating and go into full fan mode... and was only defeatable by turning off the truck for 30 minutes to reset.

Nah, it's the same bolt. You might need to chase the threads with a tap if HW3's suggestion above doesn't work. Probably some paint or something similar on the threads.

Someone in this thread makes pretty spiffy machined aluminum clamps that work with some of the covers for a “no-drill” install. But all of the factory options and most aftermarket sellers require you to drill five 1/4” holes through each plastic bed rail cap to access the factory holes that are hidden behind. While technically not a “no drill” solution, plastic bed caps are replaceable wear items and are probably cheaper to replace than buying the aforementioned machined aluminum clamps. I installed the factory hard cover (see my post above that includes a pdf copy of the install manual for full details) and found it to be a pretty simple operation. Loosen two nuts and two spring clips and the whole thing lifts off for full access. What I like about the factory hard cover is that it does not interfere with the front of the bed, so by lifting off the cover, I can put my dirt bikes in and use the built in wheel chocks without interference.

Yup... the only difference. Mag ride versus the AT4s offroad suspension with factory lift (I also got the DuraTrac tire upgrade). My buddy bought a '19 Denali while my special order '20 was stuck on the line at the factory in Fort Wayne during the strike. I generally prefer "offroad package" trucks for their smaller diameter wheels and offroad tuned suspensions. More appropriate for USFS roads with my dirtbike in the back.

Great thread... this is precisely why I went with a fully loaded AT4 over the Denali.... I hate chrome and the Denali had a LOT of it. Bonus was getting the CarbonPro which had even more blacked out goodies (badges, tailpipes, etc.).

It is included in the installation kit that comes with the tonneau. I am told that these (https://www.amazon.com/dp/B00C3MUY9K) are the correct J-nuts if you're trying to make your own solution. You'll need five for each side (the sixth threaded hole is already in place close to the tailgate. The "holes" you drill are in the plastic bed cap to allow screws to pass through to these threaded holes that are hidden behind the bed cap.

Drill holes in the bed itself, or just the plastic cap on top of the bedside rails? The factory solution requires drilling through the bed cap (an inexpensive replacement part if you're concerned)... the holes are so you can pass screws through to the J-nuts that slide into the slots in the carbon bed that are hidden by the bed cap.

Good video showing the process, but that's not a Lomax "fix," that's the factory GM solution for attaching the factory hard and soft folding tonneau covers. Use the alignment tool to drill the holes, insert J-Nuts into the factory holes in the bedside. Only difference is that with the GM tri-folding cover, you attach a single rail to the six holes on each side as opposed to a bracket to each of the six holes, but the process of creating threaded holes is the same.

Easy. Loosen two nuts and two snap hooks. Hard part is lifting off the whole thing by yourself... easy if you have another set of hands.

Yes. The kicker has two small rubber plugs you remove. The LED light assemblies need to be removed from the "trays" that they come in with the kit, and the holes left by the rubber plugs are sized to hold the LEDs perfectly.

Cool, so it’s the same mechanism as the GM “Factory” cover. I wonder if GM is supplying these parts/specs to aftermarket accessories makers (they should).

Thanks for the photo! I need these... I liked the plastic ones at first, but have discovered that the rough surface finish on them traps dirt and dust (particularly in the groove portion) and tends to make the whole truck look dirty when it's not.

Gig-Em! (℅ '95). Also, notice you have the painted wheel trim. Did you install yourself or did you order from the factory? Do you have a good pic of them, i'm curious how they interact with the (non-painted) mud guards that will remain.

Yes, hard cover. They have a soft folding one now, read above to see one guys review of it. Removing my hard folding cover is easy. Fold it up, loosen two nuts, unclip safety clips, and lift off truck. It’s somewhat heavy and awkward so better to have a helper, but I do mine myself. It’s one of the things I like about it, you can completely remove it and nothing remains on the head rail so it doesn’t get in the way when I load dirt bikes in the back, etc. The mounting hardware is all on the side rails, and is pretty unobtrusive with the cover removed.

Yeah, that's the folding GM factory cover... i.e., the one I have on my truck. Works well for me... no complaints so far.

Read above. Pictures all over this thread.

That's a new part offering.... nobody here has mentioned it yet. Let us know how it goes, but for me, I was only interested in a "hard" tonneau cover.

Nicely done! Great job finding the J-nuts to match too... had I discovered those in advance, I might have similarly tried a custom aftermarket installation. Folks take note of those part numbers/links!

I don't think it's any heavier than a comparable tri-fold from Bakflip or Undercover, etc., but yes it is bulky and heavy. They warn you it's a two person job, but being myself, I took that as a challenge to do it solo. Also, from my unboxing experience, the cover was awkwardly folded inside the box with a bunch of styrofoam, so it WILL be easier to fold and remove/install in the future versus the first time. If you think one of these suckers is too heave to consider removing and reinstalling, go check out one of the aluminum rolltop ones..

This! Exactly what must have happened. I used the block heater last night and it didn’t get a full six hours of cold soak yet. Thanks! ??

I have "smelled" the regen cycles in the past, but this thing with the electric cooling fan maxed out when it's 32 degrees out is bizzarre. Now i'm starting to worry that it's something broken.

I have a month-old 3.0L Duramax AT4 and this morning (temps in the low 30s), the electric radiator fan came on full speed while i was warming up the truck. It remained on throughout my commute, and came immediately back on when i fired the truck up 6 hours later to leave. I've read that the Diesel Particulate Filter (DPF) requires occasional flushing at elevated temperature and the manual indicates that the exhaust and such runs hot during this process so that the engine fan may be increased during this time. However, i also read that there would be some sort of notice on the dash about this mode being on and I received no such notice. I just rolled over 1100 miles. Can anyone with one of these new DuraMaxe owners confirm that this is what's going on, or is there something else going on here? I can't find reference to anything related to DPF cleaning or purging anywhere in the infotainment or dash menus,,, It's pretty annoying because it's 32 degrees out, the water temp gage is so low as to not even appear (i.e., below 160) and the damn fan is running like i just drove 100 mph in arizona in the summer for an hour.

Had this exact same issue with my new 2020 AT4 (CarbonPro) diesel. Would not work while at the dealership, but I drove 500 miles to get my truck (and it was Saturday Evening) so I made the trip home without NAV. After I got home, I was troubleshooting (seeing if other connections inside the console worked) and after plugging a USB cable into the jack next to the SD slot, it started working. This was the first time the SD card ever worked as it then began to "initialize" the card for the NAV system. Figure it was a loose connector on the cable or the jackplate. Every once in a while, I'll get a "SD card removed" error after I'm messing around inside the console, so there's likely an intermittent connection issue there. I'll have a look at it when I get around to installing my AutoStop Eliminator. Anybody seen a TSB on this?

Total BS. If you have the Nav system, you get a card. Note the cards are serialized to the truck, so you can't take one out of a buddy's truck and swap it to see if it works. Call you (idiotic) dealer and explain to them that you were not given the SD card for your NAV system.

Can you add tailgate step lights if you already have the Kicker system? It looks like the lights go into spaces already occupied by the sound system... Thx.