Rear height off by an inch - left to right

AbzDad · January 5

11 hours ago, Z45 said:

Really, 1-inch. Thats all you got to do?

Your demanding precision that is not intended. Metal is going to flex, twist etc. Go to the new truck lot and measure every vehicle and see if any are perfect.

I doubt any garage floor is level, when they did mine they slopped it toward the OH door so water would drain naturally. IF a floor drain then slopped towards drain. Did you use a laser level to check the floor grade?

yep, used a self-leveling laser on a tripod. No floor drains, it drains out the front.

AbzDad · January 5

6 hours ago, Homer1959 said:

I had the same ...problem.... with my 2025 2500HD—about 1 1/2 inches difference between sides, as shown in the pictures—back in May 2025. I measured the height in multiple spots wheel well, frame, bumpers name it and at different locations, driveway, street garage fuel station etc to make sure it was consistent, and it was. Now it’s January 26, and 6,000 miles later, everything is fine. I’m pretty sure my last trip from Montreal ( fifty first State ) to McAllen Texas, fully loaded with my 8,000 lb travel trailer and 1,150 lbs on the tongue, played a big role. Maybe the truck just needs to be loaded to get everything back in place? Now I just need to address the rear suspension noise—it’s creaking a lot even when just climbing into the cab

Guess, I need to just drive it on these bumpy NH roads. I have the same creaking sound as well. Let me know how you get that fixed... I guess I need to schedule another trip to the dealership.

AbzDad · January 5

3 hours ago, Pryme said:

I just realized I haven’t measured this since I had my leaf springs replaced so I went out and did this all critical extremely important measurment again and it’s the exact same from left to right. 41 1/4”

when you check the box for the poverty edition it includes a perfectly level, square and plumb suspension.

I am jealous!!

Edited January 5 by AbzDad

AbzDad · January 5

Thanks for all the replies/suggestions.

The truck is leveled, I have a set of SuspensionMaxx torsion keys. That's how I found out it wasn't level left-to-right. During the install you write down the height of each wheel (before and after). It was off before and I couldn't get it level after, even with the new keys. It was taken to the dealership (after the keys were installed) and had a 4-wheel alignment done. I mentioned the rear being off left-to-right and they said as long as my tires didn't wear funny, there was no real issue. The front is exactly the same height left-to-right.

I will keep trying things to figure this one out.

Chuck FB · January 5

36 minutes ago, bruceb58 said:

I understand what you are trying to say yet you are still wrong. I doubt the floor is twisted anyway and it just has a slope.

Take it to multiple spots in a flat parking lot(which will still have a miner slope) and check it in two directions.

LOL, neither of us is dissuade from our line of thinking, that's ok as I knew it would be a tough item to explain in words.

My brother had bought a different house in town about three years ago that does have a built on garage and through that process I also looked in a few of the houses he was looking at and they all varied quite a bit in floor design depending on what type of floor drain system they had and if it was a two or three car garage and if there was a drain between the two bays or drains in the middle of each bay. The house he ended up with has the most aggressive slopes I have ever happened to see but not like I am a relator and seeing inside of a huge pile of houses and garages. Its a two bay garage and with a drain in the center of each bay. The slope starts more gradual from the walls and the overhead doors but still is evident and then right near where the tires are width wise of the vehicle it begins to really slope down at all four corners of the vehicle. So the center area between the two bays slopes slightly in a crown for a width from end to end of the garage but then slopes steeply under the vehicle as well. There is hardly one true flat spot in that garage to be had ( like I said, that was too overdone ) and he can't even put a tool chest against the main portion of the front wall as it would have to be propped up on its outer wheels as it could be in danger of falling over otherwise if loaded too top heavy. There is a nook of sorts in the far end in one corner where the overhead furnace hangs and that is almost flat and so he put the tool chest there. The bonus with that crazy slope system is that any snow that falls from under the respective vehicles that melts runs under the vehicle to its drain. I've seen garages that are a total mess when bringing in vehicles that are driven during the winter as the snow melts and then runs to the wall and over to a central drain and messes up the whole floor in between the vehicles and to either side and the walls. Winter and dealing with salt and sand crap, there is nothing good about any of that. His floor would be an unsafe nightmare to ever think of doing anything much with jack stands etc, it certainly was not made for the person who wants to work on their vehicles in a garage and the obvious of this whole theme, no good at all for measuring a vehicles height as per his garage theme.

Your right that the truck should be parked on alternate surfaces that appear to be build flat and do a complete four corner remeasure.

Chuck FB · January 5

49 minutes ago, Z45 said:

The dealers can (optional) subscribe to this (fee) service and GM sends it out periodically. Its akin to "click bait" to lure you into the dealer service dept to spend money. I get them from my GMC dealer. It will show up on dealers invoice as "rpo R6J Customer Dialog Network".

Interesting, like I say I haven't a clue if the dealerships around here get into that or not but yes I agree that its a tool to bring in customers to get used to having their service work done there rather than some independent shop or in some cases doing it themselves. Once they get you in the door, then no doubt they have their recommendations, its the air filter, the shocks should be replaced, the diffs/transfer/transmission oil change services or its the battery or gee those tires look worn "we sell tires" and on and on it would go. The only thing that I have had come at me was a message on my phone that said we haven't heard from you in 8 months and to take them up on their certain service package that included an engine oil change and some other checks and rotating tires for 300.00 , of course the only physical thing that would include would be 8 quarts of oil and a filter and from there let the upsell begin !.

Chuck FB · January 5

25 minutes ago, AbzDad said:

Thanks for all the replies/suggestions.

The truck is leveled, I have a set of SuspensionMaxx torsion keys. That's how I found out it wasn't level left-to-right. During the install you write down the height of each wheel (before and after). It was off before and I couldn't get it level after, even with the new keys. It was taken to the dealership (after the keys were installed) and had a 4-wheel alignment done. I mentioned the rear being off left-to-right and they said as long as my tires didn't wear funny, there was no real issue. The front is exactly the same height left-to-right.

I will keep trying things to figure this one out.

I know I would be frustrated to see that measurement and then to bring it to the dealer and while they did not actually do the frame measurement process, just to somewhat dismiss that much of a difference is odd. When its sitting on a flat surface does the box to cab relationship seem to look pretty even and not all wonky like a twist would presumably show up to a degree. I know C channel frame trucks just sitting on uneven ground will twist around enough that they look like there is something drastically wrong with it but its the nature of that type of frame which allows for quite a twist. Definitely the C channel frames are worse for the box itself to twist enough on quite uneven ground that the end gate won't function where as these boxed frames are more resistant to that issue.

Had you had an outfit spray the underside of your truck with a rust prevention oil type product by any chance, or fluid film or other such products. As you might have seen me mention, some have claimed such products have brought on a rear suspension squeak. Also how many miles on your truck when it started squeaking, I have few miles on my truck so its not a good sample of a more used vehicle to go by and of course hoping I won't end up with a squeak and be beyond warranty by that point.

PBNB · January 5

34 minutes ago, AbzDad said:

Thanks for all the replies/suggestions.

The truck is leveled, I have a set of SuspensionMaxx torsion keys. That's how I found out it wasn't level left-to-right. During the install you write down the height of each wheel (before and after). It was off before and I couldn't get it level after, even with the new keys. It was taken to the dealership (after the keys were installed) and had a 4-wheel alignment done. I mentioned the rear being off left-to-right and they said as long as my tires didn't wear funny, there was no real issue. The front is exactly the same height left-to-right.

I will keep trying things to figure this one out.

I just put the same Suspension Maxx keys in. I found them easy to adjust. One thing that I will have to check is the level after the alignment is done. I think the height will change a bit when they move the wheels around for the adjustment.

Does the squeak sound like it is coming from the front or rear suspension?

AbzDad · January 5

3 minutes ago, Chuck FB said:

I know I would be frustrated to see that measurement and then to bring it to the dealer and while they did not actually do the frame measurement process, just to somewhat dismiss that much of a difference is odd. When its sitting on a flat surface does the box to cab relationship seem to look pretty even and not all wonky like a twist would presumably show up to a degree. I know C channel frame trucks just sitting on uneven ground will twist around enough that they look like there is something drastically wrong with it but its the nature of that type of frame which allows for quite a twist. Definitely the C channel frames are worse for the box itself to twist enough on quite uneven ground that the end gate won't function where as these boxed frames are more resistant to that issue.

Had you had an outfit spray the underside of your truck with a rust prevention oil type product by any chance, or fluid film or other such products. As you might have seen me mention, some have claimed such products have brought on a rear suspension squeak. Also how many miles on your truck when it started squeaking, I have few miles on my truck so its not a good sample of a more used vehicle to go by and of course hoping I won't end up with a squeak and be beyond warranty by that point.

No fluid film or undercoating. I was planning to take it to be undercoated in the spring once all the salt is off the roads.

I really didn't notice the squeak until about 3-4 months ago. But didn't think anything of it. Probably started squeaking around 18k.

AbzDad · January 5

6 minutes ago, PBNB said:

I just put the same Suspension Maxx keys in. I found them easy to adjust. One thing that I will have to check is the level after the alignment is done. I think the height will change a bit when they move the wheels around for the adjustment.

Does the squeak sound like it is coming from the front or rear suspension?

Squeak is definitely in the rear. You barely press down on the rear bumper and it makes a squeaking/clunking noise. Doesn't matter which side you press down on.

Homer1959 · January 5

7 hours ago, Chuck FB said:

C’est très intéressant que le camion soit maintenant positionné différemment de ce qu’il était neuf ou presque neuf. Quand tu as mesuré maintenant, quel poids avais-tu dans ou sur le camion, comparé à la première fois que tu as mesuré la première fois d’après les photos que tu as postées ?

Concernant les grincements, vous n’êtes certainement pas la première personne à vivre ça et j’ai vu certains en vouloir au fait qu’ils ont été pulvérisés avec un inhibiteur de corrosion dans leur camion, pensant que cela avait fait quelque chose aux silents à ressort, mais ont ensuite fait des travaux sur leur camion avec l’ajout de ressorts à lames par exemple, puis ils ont réalisé, hmm, Le grincement n’est plus là. Je n’ai pas non plus la réponse : toutes ou peut-être diverses raisons qui peuvent causer cela et d’après ce que j’ai compris, certains ont eu et cela pourrait être un problème d’une demi-tonne car selon un bulletin technique, les ressorts ont été remplacés.

Cependant, je me demande vraiment à quel point tes boulons à ressorts à lames sont serrés ou lâches. Je ne veux pas dire que les resserrer va résoudre le problème, mais ça ne m’étonnerait pas que la valeur du couple ait beaucoup baissé depuis qu’elle était neuve. Il pourrait être intéressant d’examiner de près vos poches de feuilles pour voir si vous pouvez voir quelque chose qui semble un peu déplacé, comme un ressort à lames non contenu dans la bande en acier qui est devenu déformé par rapport au reste du paquet (comme la surcharge effilée du bas). Je n’ai toujours pas eu de poids significatif dans ma boîte ou sur l’attelage pendant un certain temps pour aider à « faire travailler » la suspension de façon agressive, mais j’ai quand même été surpris, en vérifiant la quincaillerie du boulon en U, qu’elle n’était pas du tout prise comme je l’aurais imaginé. Le plus ridicule, c’est que ce n’est pas simple comme la méthode de GM pour serrer les boulons en U, car il s’agit d’un certain couple appliqué aux quatre écrous de manière égale, puis d’un tour supplémentaire de 180 degrés. Cela « semble » le faire monter à la barre des 180 à 200 livres-pieds sur un boulon d’usine assez neuf et non rouillé, et cela a du sens vu la taille du matériel.

Cependant, comme il fait ces bruits, etc., je ne toucherais pas au matériel mais je l’apporterais chez le concessionnaire pour qu’ils entendent le grincement et voient ce qu’ils feront, le cas échéant, avant de faire un remède maison si le concessionnaire le détache.

The truck bed was always empty when I took the measurements. Regarding the noise, yes, my truck was sprayed with Krown three days after I bought it. I can’t imagine a light film of oil being the problem, but hey, who knows? The truck will go back to the dealer when I return to Canada in April, as I think it would be complicated to have the job done here in the USA under warranty, so I’ll let them deal with it.

Chuck FB · January 5

1 hour ago, AbzDad said:

No fluid film or undercoating. I was planning to take it to be undercoated in the spring once all the salt is off the roads.

I really didn't notice the squeak until about 3-4 months ago. But didn't think anything of it. Probably started squeaking around 18k.

That eliminates that theory on your truck it would seem as per an oil or product causing an issue with bushings or attracting dirt etc into the leaf springs.

I hope you don't plan on having that tar crap sprayed under your truck, that was a thing around here in Alberta for years that was being done at dealerships and all for an upsell, not for the health of the vehicle although of course they claimed it was great. What happens is that it begins to crack and then the salt and calcium chloride gets behind it and as its holding the corrosive crap in there along with the moisture, it rots out the body and frame that much faster. Some of the oils and such that do get used out east though do work, weirdly enough that is not a thing they do here locally as whatever shop did it is no longer in business. I tried may hand at the fluid film thing with a sprayer and gallon cans but its a once a year theme and its not fun to apply. And I said screw it and I did spray down my leaf springs etc although due to how things fly around with the compressor I used an aerosol can of the competing lanolin product from the blaster company instead. One thing is for sure, shes a greasy ugly mess to touch the underside of my truck to work on it !.

Chuck FB · January 6

53 minutes ago, Homer1959 said:

The truck bed was always empty when I took the measurements. Regarding the noise, yes, my truck was sprayed with Krown three days after I bought it. I can’t imagine a light film of oil being the problem, but hey, who knows? The truck will go back to the dealer when I return to Canada in April, as I think it would be complicated to have the job done here in the USA under warranty, so I’ll let them deal with it.

I had to laugh as you quoted me and I had no idea I was that well versed in French as I certainly can't speak it LOL, uh the magic of the internet.

Who knows if the Krown did anything or not, seems others on here are having the noise and have never applied anything. I agree that best to leave the springs be for now until you get back to Canada and have them sort it out although you can look over your suspension just to make sure you don't see something amiss such as loose ubolts that you can move by hand ( that would not be a good sign ! ), and yes you could take a deep socket and I can't recall what size that was now it may have been a 27mm or able to use a 1 1/16" socket but I could be wrong on the size, and give each one a good pull with a longer handled ratchet or if you do carry a torque wrench with you.

PBNB · January 6

One thing to consider with the squeak is that it could actually be the e-brake!

I know it's a long shot but I have a squeak in my trailer that is very subtle but is there when I move around inside the trailer. The noise is from the brake shoes and a slight trailer movement causing the brake drum to move.

Try setting the e-brake and see if the noise goes away.

Item #13 shows the brake shoes that sit inside the rotor hollow. There are a lot of moving parts to these brakes.