GMC4Zee

I also have had the issues and feel its related to not getting the camera connection in there tight enough. Also I think it has to be connected before the truck is started or "on" as there are times where I have got the connection tight but needed to shut down the truck before it would recognize the camera. I did move the camera/7pin up into the bed as I have a 5th wheel.

Random, will try this weekend. Been in lockdown due to covid this week. Hope the pedal process works.

I would say that maybe there is air in the lines somewhere. When you push it to the floor a few times you are purging it further down the line. Possible past the ABS system. I have always wanted to replace the rubber front lines with SS ones and bleed the system. I have SS lines from my 2016 2500. If they fit the '21 AT4 3500 I would put them on. I have not looked into that yet. I also have had the creep issue and almost rear ended a car at a stop light.

Just as the topic says. Has GM increased the the frame coating or do they still rust after 1 winter in the salt belt. My 2016 looked bad after 4 years even after I painted a number of areas. Don't want a rusted frame on my 1 year old truck.

Good luck. GM has these computers all locked up. If anyone is tuning it will cost plenty of cash. Thats all I heard.

Thanks everybody!

Just as the title says, just need a quick answer. Dont have the manual available. 2021 3500AT$ with 20" wheels. I think its 110lbs

Kjduvall, tell me more about the pedal commander. Does it give better off the line response? Feel like more power? I tow, will it help that aspect?

I have the HD surround vision on my '21 AT4 in the color you are looking at. The one feature of it I did not know about till I was hooked up to my trailer was the fact that when you turn on a signal, you get the camera view from the mirror mounted camera which helps you not cut corners too tight and see objects you may side swipe. Also the cab mounted camera helps with 5th wheel hitching as I use an Anderson hitch which has the ball and socket. Adding the extra cameras might get pricey. Adding collision stuff would include paddle switches on the dash besides all the sensors and wiring plus a BCM update. I ordered mine to get all the options I wanted. Only option I don't have is sunroof. Oh yeah love my heads up display. Had one on my G8 and really missed it.

I had an '16 2500 HD that I put fox shocks on and slightly larger AT3 tires and the ride was acceptable. My '21 3500 AT$ with camper/snow plow bars is ok on smooth roads but can bounce you out of the seat on bad roads. I do tow and like the ride so I will try fox shocks in the future. I did not go with remote reservoir adjustables on last truck but like the idea of it. When compared to the stock shocks the foxes were easier to compress which would give a better ride towing or not.

On my 2016 HD I ran Cooper AT3s. They did well in mud and OK in snow and good in rain. I only had them for 25K so cant tell you how they are long term. My feeling is if you can get 35K out of a tire on these heavy trucks, you doing good. I did have to rotate the Coopers every 6 K as they tended to cup on the outside of the front tire then it would get noisy. Just rotated to rear and all was good. I will look to replace the factory Goodyear's once they stop performing as expected. The Coopers are heavy but I did go up to an 11" wide tire.

My '21 3500 HD is only 1" taller than my '16 2500 but the bed seems lower. It is longer as i went with the crew cab over the double but the good news is it still fits in my garage! Brought the demo home to make sure. The 3500 does not have the extreme rack front to rear that the 3500 had. I think it rides smoother and definitely steers better.

I have the full camera option and it comes on when in reverse from tailgate. I use the cab mounted when hitching up the 5th wheel but am disappointed that there are no grid lines on cab view. That would be helpful to judge distance from the pin. As for the front view it comes on when the driver display goes from yellow to red which must be 12" or less. I just switched my bed and bumper trailer connections so I can plug the rear trailer camera into the bed connection instead of running wires down to the bumper. Have not tested yet or set up "invisible trailer" option. I know I will have to cheat the system to make it work.

Well it was bound to happen. I gouged up my multipro tailgate top cap with a friends 5th wheel. Wont get into details of how I did it but need to replace the cap. There does not appear to be screws holding it on like previous years. So any help on removal and replacement? On another note the inner top cover of the tailgate is not available as a replacement part. They want you to buy the whole top unit at $350. Guess I will be leaving that one be for now.

I have some SS front brake lines that I never put on my '16 HD. If they fit my '21, I might try them. That would give better pedal pressure. But I agree with all that it does take some foot power to activate.

I think the newer vehicle has a coating more like paint. I have not done any work on the truck yet but in the wheel wells it looks more like smooth paint. Being in the salt belt I may get the oil coating just in case.

Ryno12, a couple things about the system and your truck. The camera plugs into the connections on the bumper not in the bed where you most likely plug in the 5th wheel. I have a '21 AT4 3500 and will need to swap the connection so I can plug in with the line feeding down the pin. Also you will have to spoof the system as it was not designed for 5th wheels. Most have got it to work. I am in the process but have not run the camera wire yet. My 5th is 32.5 feet long. Plenty of threads on forum about it. Pissed that GM did set it up for 5th wheels.

I went from a '16 2500hdSLT and it had that raked look where the rear was much higher than the front. On my "21 3500 HD AT4 it sits more level and I was able to lower my 5th wheel hitch on notch and still have great clearance. The longer bed also benefitted me with my Anderson hitch. Truck height overall is 1.5 inch taller but it seems the box is lower than on the previous truck. Only worries are with the full function tailgate I will have to get a special receiver ball if I want to to tow any bumper pulls and the drop down gate will hit unless you have a vey tight initial drop bar.

I thought the HUD needed special glass as it has reflective material in it to make the HUD show. When I had it in my G8 the glass people asked if I had a HUD or not. I like mine but turn signals would be nice.

Any seat of the pants improvement other the sound ?

Nevermind, I reread the whole tread and now know what I need.

Mavito, I agree 100%, Most HD will be towing 5th wheels not bumper pulls. They really need to update the firmware to accept 5th wheel parameters and when you order the 5th wheel package, change the camera hookup location to the bed. Poor execution on GMs part for sure. I hope they read this! I will be moving my camera port to the bed and hope with a 32.5 ' long 5th wheel i have enough cable.

CoolJ , when swapping the receptacles, you remove the 7 pin connector and swap to new one going in? Do you have to fish the camera harness up to the bed and bring the 4 pin harness down to the bumper? Just got down there and looked to try to sum up the job before I start. I assume there is enough cable to get the camera harness up to the bed?

I took my 32.5' 5th wheel for a ride this weekend with my 3500 AT4 HD and was pleasantly surprised. I no longer have any chunking, I was able to lower my Anderson hitch ball one hole and loved the fact that when I turn on a signal to make a turn I get a camera view of the whole side so I can see if I am going to cut a corner too sharp. The ride is smooth and although I did not do any great elevation climbs the power feels adequate for my gasser. Nice improvement over my '16 2500HD.

On my '21 3500AT4 HD its 22" to center of hitch