Posts posted by calgator73
On 2/20/2023 at 7:32 PM, claw2791 said:
Wonder why gm only lists it as an upgrade for 2022 and newer trucks. Control arms are the same...can't really find a difference in part numbers.
They are everywhere. Search
40 minutes ago, Dan VonDielingen said:
Posting this to try to help others. I have 2019 GMC Sierra AT4 New Body Style with 39000 miles and the breaks were screaming for these first several rotations (e.g. down the driveway) and after sitting for just a short period of time. The front was showing 67% left and the rears were showing 81% left. I don’t do any pulling with the truck. Called the dealer and they told me this was normal….told me something about semi metallic brakes and metal on metal squeal is normal until warmed up. I can tell you there is nothing normal about this. The brakes wake up my neighbors in the AM and my startle my co-workers when leaving work. I could find some info on the web…but not much. So, I decided to replace the front and rear pads on my own as brake squeal is not normal. I have normally replaced my brakes on older vehicles, so gave it a try. It was an adventure. I went to local advance auto parts store and bought the pads with the wear sensor. Part # was GNAD2173 and PXD2174H. Total for all pads/sensors for ~$130. The pads were ceramic and came with the replacement wear sensor. There is one sensor on the front left and rear left wheel. With parts in hand, I went for it.
Rear Brakes: I started with the rear. Removed the tire, and the job looked straight forward. Removed two 14mm bolts which allowed for the top of the caliper to come off. It was a bit difficult to get off as there was a plastic electronic emergency brake housing attached to the caliper but i was able to get it off. Replaced the pads and clips super easy. Went to compress the piston back to put the housing back on…and there was no compressing it. I went on line and found a very good short video on how to put a Silverado into emergency brake service mode. Title of video is “2019-2020 Silverado Turn On Brake Service Mode to retract emergency brake pistons / motors”. Basically, with truck off, press the brake pedal and then push in the emergency brake button for 10 seconds, take foot off of brake, finger off of of emergency brake button, and immediately press and release the emergency brake button. You will hear the emergency brake motor activating. You can then turn on the truck and will see a brake light with a wrench symbol flashing. This is how you know it is in brake service mode. I turned the truck off, then went to see if I could push back the piston. It pushed back with ease. I should have put the truck in the brake service mode first. The final step on the rear driver side wheel is to replace the wear sensor. The only tough part here was getting it disconnected at the harness. I ended up pushing the white tab away from the connector, and with a pair of needle nose pliers pulled the white tab out. Then there is a grey tab under the white tab that you can lift up/or push down (can’t remember) and the old wire disconnects with an easy pull. I then put the white tab back in, and inserted the new plug side of the sensor. It went in with ease and then I pushed down the white tab to secure the new sensor in place. I am sure there is an easier way but this is how I got it to work without breaking anything. The wear sensor easily slides into the brake pad in the groove. From there I put the caliper housing back on, secured the caliper with the two 14mm bolts, put the tire back on and went to the passenger rear. With the brake service mode still in place, I repeated all the steps on the passenger rear side (all steps but the wear sensor as there is not one on the passenger rear). With both rear brake pads replaced and wheels on, I went back into the truck and turned on the truck and with foot on the brake, and in park, I pushed the emergency brake button for 5 seconds, this takes it out of brake service mode (the light with the wrench goes out). Then, I took it for a drive, and the brakes worked fine. No error codes. The only thing I could not reset was the brake pad % on the driver information sensor. I have seen a couple posts on this, but seems like it has to be reset with a scanner if the wear sensor has worn yet (and my truck with 39K miles on it hadn’t yet “opened” the wear sensor. In summary, if did this again, I would put the truck in brake service mode as the very first step. All else was pretty straightforward. The sensor connection (at the harness) was a bit of a pain. I went slow as wasn’t too familiar with it, and didn’t want to break the plastic harness. By the way, the rear brakes still had 80+% of the pads left, so there was no reason they should have been squealing.
It was getting late, so I decided to do the front brakes the next day. The next am, I did the front brakes without putting the truck back in brake service mode. I thought the brake service mode was just for the rear brakes (that had the emergency brakes). This may have been a mistake (by not putting the truck in brake service mode). The other thing I didn’t do was disconnect the battery (which may have been a mistake as well). I say this, because when I replaced the front brake pads, it through a bunch of codes. ABS, traction control, other warning codes/lights and put the truck in a mode where couldn’t drive it beyond 43 mph and brake pad was very soft/slow/mushy. Will get to how i got that fixed here in a bit…but first, this is how I replaced the front pads. The front pads were easier than the rear to replace. Pull two cotter pins, pull the 2 pins, the brake pads easily come out. The pistons easily push back (but I think it was this that caused all the error codes). Guessing the new trucks have sensors that sensed the hydraulic fluid going backwards and didn’t like that. That is when I think if I did it again, I would probably put the truck in brake service mode and probably fully disconnect the battery. Not sure if this would prevent what happened to me…maybe someone else has that answer. Anyway, the front right was super easy to replace the pads and clip. The front left had the wear sensor. I disconnected it like on the rear. This one was a bit more challenging to get the wear sensor to clip on the brake pad. I just had to get under the truck a bit to better see the sensor / brake pad (truck was fully chocked for safety). Once i got to where I could see the connection, it went together easily. With both fronts done, and tires back on, I hopped into the truck thinking I was done. Turned the truck on, and got a ton of error codes (including the soft brake pedal and 43 mph limit). At that point I tried to put in brake service mode, thinking it might reset codes…but did not. I disconnected the battery, thinking that may reset codes, but it did not. I ended up calling a local brake shop, and had to have them clear the codes for me. They were able to do this in a few minutes, and then everything was back to normal (no 43 mph limit, brake pedal was normal, no warning lights, etc.). All of this, but my brakes no longer scream!!!
By the way, the fronts still had at least 70% of the pads left, so no reason for them to scream. All 4 rotors were also in great shape. As with the backs, I could not reset the front % brake pad sensor from the driver information center. Whenever I get this to the dealer for something, I will have them reset it (think that the brakes weren’t worn enough for the reset feature on the driver information center to be able to be reset). Saw a bulletin that it has to be reset with an onboard diagnostic scanner (which I don’t have).
All in all, this is way tougher than any other vehicle I have done due to the technology. The mechanical part is straightforward, it was the other electronic stuff that got me. Hope this helps someone.
Good write up. You're right regarding disconnecting the battery after you put the truck in mx mode.
Consider not only the tongue weight of the trailer but the cargo going in the bed and the way to the passengers. Also consider where the water is going in the trailer sometimes if it's built correctly they put it right over the axle and other times they put forward of the axle so traveling full may really hurt you. You will probably be maxed out as far as your GVWR is concerned. With a weight distributing hitch you should be able to stay below all of your limits. On the surface that sounds like an easy tow. Just be aware that has tongue weight goes up these trucks porpoise like crazy
An alternative, if it is close by to you and your need isn't too frequent, is just to rent a heavy duty truck from Enterprise Truck whenever you need it. You can specify gas diesel short bed long bed even make and model if you give them enough time. No need to worry about ad valorem taxes, maintenance or warranty. The biggest limitation is it has to be a bumper pull.
Bought my 20 AT4 Carbon pro for 62k (66k MSRP) in August of 20. Optioned out the exact truck I have and it's almost 81K for a 23. wtf this is crazy.
1 hour ago, Moose0814 said:
I know there are some other posts about this, but has anyone found a DIY fix?
My column shifter moves/vibrates at highway speeds very noticeably and when in Drive has some serious slop of 1/2'' to 1'' up and down. It isn't as noticeable under 50MPH, but at lower speeds over bumps very noticeable.
I feel like its gotten worse with time, but the tech said it is normal compared to other trucks. I also am not sure he was trying it while in Drive. In any other gear it feels stiff.
any input or feedback appreciated - dealership will definitely be a PITA about this one.
I have the same slop...it's been basically the same on my 07, 14 and 20. Vibrating the shifter though could be caused by tires or practically anything in the driveline. Heck even a busted tranny mount could allow for enough movement for the linkage to do strange things.
1 hour ago, wslr85 said:
Thanks all for your replies & info, thats why I posted this topic, I’ve heard & seen many videos of it failing specially on dyno and also many videos of it going fast with stock shaft, my self had 2011 Z71 and reached +137mph many times before knowing its unsafe, now on the new 2020 I reached 125mph and can go more but thats what I set the Pulsar LT to, and the stability was great, as I said I only do it on open highway far from other traffic, it’s a truck for sure it wont be safe to maneuver between cars or lanes at high speeds, are all truck trims have the same shaft?? Denali, TB, LTZ, …?? All years model same shafts 2008-2020??
I think the issue on the truck in youtube video is trying to do burnouts applying too much brake, the photo I sent is truck with some mods, exhaust, intake, stock shaft
If you know the max speed of the shaft you can use this formula I found on another site:
MPH = (Driveshaft rpm * tire diameter in Inches ) / ( Gear Ratio * 336)
Using the gm accessory steel shaft as an example on my truck:
Deaver makes a kit for these trucks that replaces the overload spring with a progressive pack. Are you running loaded? Is your bump stop hitting the axle? That's a hell of a bump on a highway to bottom your suspension.
Guess I learned something new. Wouldn't have thought they would remove the TB to clean vs using upper intake cleaner. I've never cleaned my TB...just use top tier fuel and the right oil. Glad you got it sorted.
On 12/27/2022 at 8:04 PM, AT4Juan said:
I remove my coldair intake tube to check the throttle body for any oil residuals from my intake and sure thing the walls and the flap were dirty and oily, not that bad but still dirty. I took it to the dealership to get it clean and most important re-learned, I was thinking to do it myself because its easy, but then the relearn thing, so naahh. They clean it real fast, I was in and out in less than 45 minutes and the truck its been running good for the last 5 days.
That is weird. hard to believe a cold air intake tube...wait....relearn what? There have been people who upgraded to the GM cold air intake and failed to get the calibration for the MAF complete and had all kinds of drivability issues.
Just purchased a 6100 sq ft house and first time fill is $2.19/gal. Effective rate after fees is $2.22. All other fills are at 2.99 this year. Just found tank farm which is advertising $1.70 this year for my area.
Other than being more resistant to impacts is there a benefit to the new driveshaft upgrade?
20 hours ago, Moose0814 said:
I had an Extang Solid Fold 2.0 on my first truck that I have had in storage. I replaced it with an Extang Xceed Low profile folding - it leaked too much after many adjustments, so I put the Solid Fold on and now it seems to be leaking from the outer hinges.
What do you recommend for a hard folding tonneau that is as waterproof as possible? Any remedies to make an existing more water resistant?
I am on my third roll-x..well now it's called BAK Revolver X4S Tonneau Cover... IMO they provide a good balance of security, water tight and visibility out back window if you don't have the camera mirror. I get a little water intrusion at back by the tailgate but I haven't been worried about it.
I tend to agree with Tim with it being electrical. Set your ebrake and have someone exercise the vehicle a little while you observe under the hood. Could be simple chafing on a harness that moves ever so slightly when you shift into different positions. Might also consider just letting it idle in park ebrake set and crawl under the truck moving harnesses by hand. Any kind of harness issue could cause a communications issue that results in a stall. Still under warranty?
That sounds very similar but more intense than what I experienced as I could only hear the noise outside the truck. I take it with belts and pullies being replaced the dealer has isolated this to the engine bay and not the transmission bellhousing area?
5 hours ago, Joey Livingston said:
Have a 2021 6.2 Trail Boss and having whining noise on acceleration when driving only. Replaced pulley and belts already same issue. It starts making noise after 2k rpms and continues.
Couldn't play your video. Can you replicate by brake torquing the motor a little?
11 hours ago, AT4Juan said:
Hi everyone, Im new to this forum, I drive a 2020 AT4 6.2, truck has 42,000 mil. Truck is runing good and strong, but a while ago started to act weird, when I put the truck one reverse and I press the pedal (a lil bit, for the truck just to move, like when you in the mall) you can feel the engine like vibrating and when I put the truck on drive, it shut off (but not always), I put the truck back on park and it start right away and put it on drive and work just fine, when Im driving down the road the gruck works fine, is just when is idleling in reverse. I want to know if some one has this problem before or have any idea what it coul be
That sounds weird and almost like your stop/start system is not right. So when you idle in reverse engine turns off. What happens when you shift to drive or park? Does it restarts or is it a stall and you have to restart the engine manually in park?
12 minutes ago, Diamond817 said:
I have a 21 RST 4wd, I drive 75% highway, 25% city, no off-roading ever (I know), no industrial areas, and have about 37,000mls now. I've noticed the engine bay and engine in this truck likes to get dusty and dirty, like everything gets covered. I low pressure rinsed it down and it cleaned up easily, but a few thousand miles and it's covered in dust and dirt again. Has anybody else experienced this? Does it have something to do with the new design of these trucks? I don't have the Z71 skid plates, could that have something to do with it?
I don't know... since I got my driver's license when I was 16 I've washed my engine bay down every single time I've washed a vehicle. It just so happens that some weeks are worse than others.
I think if I was going to go for the 22s I would probably spring for SuperCruise. There may be a different calibration for the adaptive suspension based on a factory order with 22s versus 20s. I know for a fact on the previous generation there was a different calibration and different shock part numbers with auto ride.
On 11/30/2022 at 1:34 PM, Weekend101 said:
No idling, tires are 285/65R18 AT. With these tires last month on 1500 to 1800 miles around trip the truck did 18 miles per gallon. That I am happy with. What has me confuse is when filling the tank up it would always show 425 to 435 miles range. But now it is showing 312 miles range and I haven't even moved the truck. In my books a full tank should show the same with each fill up. The faster the fuel gauge goes down the worse mileage one is getting. But to lose over a hundred miles on a fill up seems odd. This is what the computer range is showing. Fuel gauged is on full. Going to try a fuel additive and maybe fuel system cleaner. Also going to check my mileage by hand and see if the computer range is off.
I think it calculates that range off of the last 50 mile average. That 312/22=14.2mpg. Seems reasonable considering your hwy fuel economy is 18.
9 hours ago, Big_Kahuna said:
so the at4 come from the factory with 3 different size tires 275/65/18 265/60/20 and 275/60/20 , what I don't understand is why gm put different size tires for the all terrane tire what is 275/60 /20 and mud terrane they put 265/60/20 WHY ??
Unless they have really changed things up you get a factory choice between an LT275/65/18C MT and a 275/60/20 AT. That's why you have those two choices? I guess the answers come down to style preference and capability desired. Those mud terrains are really good but loud and the all-terrains provide a really good balance and are very quiet. Also the 18s are a 32-in tire and the 20 is a 33-in tire.
I loved the factory trail runners quiet ride, exceptional wear and great fuel economy. They didn't have the street presence of a dedicated off-road tire so I switched up to the grabber ATX . They wear well.... But they suck for daily driving.
4 minutes ago, FJB said:
I was looking online how can gauge cluster be set up on the 2022 refreshed models but I was not able to find what was I looking For you pull up readings like coolant temperature transmission temp oil temperature oil pressure , this is by far most useful info on a truck in my opinion, here is the set up you can pull up on a ram, this is my ram on idle
You might need to do a screen capture of that picture to convert it to a JPG file
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"Wooshing" noise like running water behind the dash on cold start?
in 2019-2023 Silverado & Sierra
There was a problem on another GM vehicles as well and it usually requires getting air out of the system.