Jump to content

Recommended Posts

Posted

Hi, first post here. French canadian so please be patient with my english 🙂 

I bought my new Sierra HD2500 SLE Gas in april 2025. I am in love with this truck, is it going to last ... well only time will tell.

 

I come for an F150 XLT 2014 3.5 eco. This truck served me well but was starting to be unreliable. I was hauling a travel trailer of 7500lbs 30 foot long , and even being maxed out it was ok to drive our 8000km trip down to texas every year I looked a the f250 but not much difference with the interior and exterior so i decided to give a chance to GMC... 

 

ok enough of me, now tell me I am setting up my equalizer hitch and I realized that when I measure (unloaded) the rear height from the fender wheel well that I get 1 1/2 higher on the r/s versus the l/s. have you ever noticed something similar ?

 

The truck drive straight, no problem detected, I measure also from the frame and the bumper and its consistant, always higher on the r/s. I also noticed the the helper spring is closer to the leaf spring on the l/s .... so if I am not asking for too much can you take the measurment to confirm that yours sit level or not like mine , that would be really appreciated . Im leaving for a 700 miles trip with the trailer and the truck fully loaded maybe that all i need to put everything under there in the right place ? 🙂 

Depending of your feedback I might pay a visit to my dealership. thanks in advance  

 

Posted

Welcome to the forum. My 2022 2500 measures exactly the same. From the uppermost point in the rear wheel well to the concrete floor of my level garage it is 41 1/4” 

 

make sure you’re on a flat concrete or asphalt surface when you measure. If you are and it’s an inch and a half off there is a problem. 

Posted (edited)

In my case its 40.5 l/s. 42 r/s ... I think a visit to my dealership will be in the plan thanks Pryme 

Edited by Homer1959
  • Like 1
Posted
32 minutes ago, Homer1959 said:

In my case its 40.5 l/s. 42 r/s ... I think a visit to my dealership will be in the plan thanks Pryme 

Yeah that’s not right. Something is wrong with the suspension. Let us know what it ends up being. 

Posted

Make sure the part numbers on your left and right rear spring assemblies match. They are painted in large numbers on the bottom. The gas tank is on the left side, so measuring with a full tank will cause the left side to be slightly lower, but I wouldn’t think that would cause 1.5 inches of difference. Also, don’t accept the dealer adjusting the front torsion bars to compensate if the rear suspension is really the cause for the lean. 

Posted (edited)

the front is almost perfect so if they touch the torsion bar they will screw up the front but thanks for the heads up , its something that I will discuss with them  btw same part number confirmed

 

 

left side helper spring is almost touching leaf spring on the other side the gap is much more important, anyway I contacted the dealer for an appointment 

 

Edited by Homer1959
Posted

What do you think about Jon's comment about the gas tank being on that side?

 

I am experiencing the same thing on my 2013 C3500 right now and am curious what you find out.  It is a service truck, so my first thought was an uneven load in my cabinets, but I have ruled that out and actually have more weight on the right side now with no change to the 1 1/4" inch difference, and helper spring gap as you have described.  I have been wondering if my leaf springs are worn out, but you have new leaf springs, so I am curious what you find.  My search online revealed a lot of comments about a classic Chevy lean due to the fuel tank being on one side.  I have been driving Chevy trucks for 40 years and have never experienced a Chevy lean until now.

  • 3 weeks later...
Posted
On 8/19/2025 at 9:44 PM, Handy said:

What do you think about Jon's comment about the gas tank being on that side?

 

I am experiencing the same thing on my 2013 C3500 right now and am curious what you find out.  It is a service truck, so my first thought was an uneven load in my cabinets, but I have ruled that out and actually have more weight on the right side now with no change to the 1 1/4" inch difference, and helper spring gap as you have described.  I have been wondering if my leaf springs are worn out, but you have new leaf springs, so I am curious what you find.  My search online revealed a lot of comments about a classic Chevy lean due to the fuel tank being on one side.  I have been driving Chevy trucks for 40 years and have never experienced a Chevy lean until now.

My truck is going to the dealership on Monday, but I’m not expecting much. I assume they’ll just say, "it is what it is." I’ve measured around 10 HD trucks on their lot, and none are perfectly even on both sides—they vary from 1/2 to 1 inch. Mine, however, is at 1 1/2 inches. Bent frame? I’m not sure. I’m curious to know what specifications these trucks are supposed to meet on a frame machine—GM must allow for pretty wide tolerances. 

Posted

The truck will be back tomorrow. According to the verdict, it falls within GM spec. The advisor sent me the GM diagnostic procedure with all the measurements, and my left rear, front left, and right sides are spot on. However, according to MY measurement the rear right is outside the spec. The rear should be 42 inches ± 1/2 inch, but my rear right side is 1 to 1 1/4 inches higher than the left side. They assured me they took their measurements on their alignment pit and confirmed the truck is square, so there’s not much they can do. I’ll double-check tomorrow, though I’m pretty sure the truck isn’t square. Even if I’m right, they can’t lower the rear—raising is possible, but lowering isn’t. Anyway, I’ll leave it as is; it’s not a big deal since the truck tracks straight and everything else is fine.

Posted

I had a couple of thoughts and one of them was to make sure the tires measure the same height on each axle, that of course is a real long shot but how crazy could it be if there was a tire that was physically a different size, the odds would be very low though. Also when you have the truck on a level pad, measuring the fenders again but also measure from a location on the frame to the cement on both sides and being that the frame is inboard of the fenders it won't show as an exaggerated measurement. I've wondered also if there was something off with the box to frame mounds causing that height discrepancy. But you might have a bit of a mismatched ( in manufacturing ) rear spring pack, I don't know if that is possible or not but again just another thought. 

 

My new truck was not level either from side to side but I soon could see what was highly likely as the culprit and that was a poor setting of the front torsion bars and the massive difference in the exposed threads on the torsion key bolts was very telling and also the difference in gap at the jounce bumpers. My right side was lower over all, the front right was a 1/2 inch low and the right rear was around 3/8 or so. I adjusted them ( lifted the truck off the cement first ) and I did choose to raise the front just slightly ( that maximum 25 inch to hub ) which was only a 1/4" higher than what the left side started out like from the factory but that was my personal choice to do that as I could have stayed within the factory height. Changing the front as I did brought the rear into the same height so that was that. I did have the alignment checked after as my steering wheel was off from the day I test drove it so they corrected that and that's all they had to do but the truck before and after my adjustment drove straight as an arrow so nothing changed with that aspect. I made sure to have a full tank of fuel when doing the measurements so I didn't end up with a left side lean after all of that. 

 

I went through a situation with a new older chev half ton pickup years ago and it was leaning to the left and would have sworn it was the rear leaf springs ( I even went through all the work to swap them side to side ) and that made zero difference after all that work but that made me look harder at the front and it was indeed the front that was the whole cause of the lean, once it was adjusted to be level that brought the rear around. What was so puzzling was that the rear was out a lot further than the front and its never made sense how that was physically possible but there it was. I suspect because I had the heavy factory torsion bars on that half ton and they came with wimpy rear springs, that may have allowed for the rear to react so much to the front end lean. 

  • Like 1
Posted

Late on this but…

Running 60 psi in the front tires and 65 psi in the rear, the front measures 40-3/4” on both wheels.  (20” OEM tires)

The back measures 41-1/2 on the RR and 41-3/4” on the LR.

Point?……… It’s pretty damn flat side to side.

  • Like 1
Posted
26 minutes ago, Capt Bob said:

Late on this but…

Running 60 psi in the front tires and 65 psi in the rear, the front measures 40-3/4” on both wheels.  (20” OEM tires)

The back measures 41-1/2 on the RR and 41-3/4” on the LR.

Point?……… It’s pretty damn flat side to side.

Well, I wish mine were like that, but it's not. Despite the fact that they put the truck on an alignment pit, it still looks higher on the right side to me. They sent me a picture of the truck on their ramp with a 3-foot bubble level on the rear bumper, and the bubble is dead center, so it must be an illusion, lol. Anyway, it's documented, and I have no drivability issues, so it is what it is. My tape measure must have been made in China since the front is dead on GM spec, as is the left rear. My only discrepancy is the rear right side being higher. That must be the Chevy lean I've read about on various sites. Thanks for sharing your measurements.

Posted
1 hour ago, Capt Bob said:

Late on this but…

Running 60 psi in the front tires and 65 psi in the rear, the front measures 40-3/4” on both wheels.  (20” OEM tires)

The back measures 41-1/2 on the RR and 41-3/4” on the LR.

Point?……… It’s pretty damn flat side to side.

As the saying goes, your golden !. Nice that someone in the factory got the front level and the rear happens to fall within what is no doubt a decent factory tolerance. As you probably read my comments of my own truck, someone was too quick or cross eyed in adjusting my torsion bars but at least a very easy remedy and once I did that I was very satisfied with the outcome. I never said one word to the dealership about what I had found or then had done, I knew it needed the "steer ahead" adjusted and the other numbers they generated were fine so all was good in the end. Of course I only caught the issue because of my past experience and measured this one and realized it was out, it didn't just jump out at me as it was not enough of a lean to really catch the eye. I've seen some trucks and that is usually an older truck going down the highway that I am following and it just stands out if has a really bad lean, may even be a broken leaf spring in a case like that or the frame/box twisted in an accident. 

  • Like 1
Posted
23 hours ago, Homer1959 said:

Well, I wish mine were like that, but it's not. Despite the fact that they put the truck on an alignment pit, it still looks higher on the right side to me. They sent me a picture of the truck on their ramp with a 3-foot bubble level on the rear bumper, and the bubble is dead center, so it must be an illusion, lol. Anyway, it's documented, and I have no drivability issues, so it is what it is. My tape measure must have been made in China since the front is dead on GM spec, as is the left rear. My only discrepancy is the rear right side being higher. That must be the Chevy lean I've read about on various sites. Thanks for sharing your measurements.

Funny thing is my 2018 1500 was like that also. Always thought it was my fat ass and the fuel tank. When towing, I leveled it off with the air bags.

  • Like 1
Posted

Ive never heard of the Chevy lean but recall reading PV4 magazine (the old timers here may remember it) about the Toyota Land Cruisers having a lean to them.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Latest Articles

  • Posts

    • Can it still be Assembled I?    Stribeck says that we need a certain amount of viscosity under conditions of load and velocity to prevent two surfaces of a know roughness from tearing each other asunder. And we have marketing trying to tell the masses that those two surfaced require less of that commodity due to more exact limits being placed on the same old clearances. We also know that there are limits to how hard something can before it becomes to brittle to be viable and to smooth to 'wet' the surface and that both of those conditions have been known and met since about the Second World War.    That viscosity value shook out at 10 centistokes at 212 F just under a hundred years ago.  Give this a look: [Anton Parr]     What is advertised is the Kinematic viscosity (mm2/s) or that which has been density adjusted but the value we are after is the dynamic viscosity (mPa.s) or true viscosity. You can see that this number is dependent on density thus base stock and temperature. You can also see that an SAE 30 doesn't reach that value in this example. However an SAE 30 that is at the upper end of the SAE 30 range; 12.5 cSt (mm2/s), might. 12.5 * .83 = 10.375 (mm2/s). If you could find an SAE 30 at the upper end these days.   Then there is the complication of viscosity modifiers or VII or VM, whatever you wish to call them. Polymers added to very thin base oils, perhaps 3 to 6 cP oils, that will meet the SAE *W30 spec at 'tested' shear rates and 100 C/212F  target temperature. So a polymer fortified base that is a fraction of the 10 cP requirement Stribeck insist upon.   This could be all well and good if those polymers didn't have two very problematic 'features'. They shear or loose viscosity both 1.) permanently and 2.) temporality. And they do both omitted in the advertised data with the distinct  purpose of deceiving the consumer of the actual operating state of the fluid. I've shown the example of Warren Oils COSTCO 10.91 cSt 5W30 formuation several times where the 100 C HTHS value is 6.9 cP!! That's the temporary shear down and with and SSI or shear stability index of 9.4 cSt. Note the intentional deception in using mixed units?    After a short while that 9.4 cSt oil has a viscosity corrected dynamic value of 7.8 cP. But as the SSI is still within the range of an SAE *W30 whose lower value is 9.3 cSt.    This allows them to continue to call this SAE 16 weight oil a 30 weight, the cake, and still meet the API requirements for fuel efficiency IMPROVEMENT mandated by the EPA. The eating of the cake. By the time you've worn out your motor doing the responsible thing by adhering to the warranty requirements, (the stick), you get deprived of the carrot, wear control. So sad, to bad.   So what can be done? Do I need actually say? [Anton Parr]       Even this must be monitored if the oil is on the low side and the VII an organic or you opt for a 0W40 with an even lighter base oil and more / higher MW VII. (Note the lower density of the 40 weight versus the SAE 30 mono-weight?)    There is another workaround. Temperature. An SAE *W30 run at a bulk temperature of between 180 and 195 F.    Being the belt and suspenders sort I am I do both. Run it cook and run it heavy.    In Part II I'll work the AW package. 
    • So, do I go elbow-deep on this thing or list it for sale and play dumb? Seems to "runs good."   I'm about $1200 away from having: -a rebuilt injector ($300) -a new cat ($250) -a new cat back exhaust (OE style) ($300) -a new AC compressor ($200) -AC refrigerant charge ($150)   In theory, this should rectify the obvious detracting issues from its value and operability. Cold AC with a non-squeaking AC pulley both sounds and feels good. An exhaust that isn't cut/hacked in 17 different places and doesn't vibrate on a crossmember would make it sound and feel less janky. A working cat would help the stink, and will save the earth, but *if and only if* the fuel system is working properly, which would also address the intermittent "rich" CEL.   Heard a good one... CEL for "Rich condition" means you haven't spent enough money on the truck lately, and it's letting you know.   Rebuilding the injector would seem to be the most important part. Replacing the cat would be secondary. I don't think mine is plugged or overly restricted, but it might be a little restricted? I have no good way to tell other than seat of the pants feel. I hate the smell.   The current theory is I have a rich idle problem: A bad fuel pressure regulator, or a leaking injector(s) being the highest probabilities. I already replaced the FPR but that doesn't mean its replacement isn't also bad. It was a new part from Dorman, but the packaging looked like it had been sitting on a shelf for 20 years.   This is the (single) upstream O2 sensor shown at idle. I'm getting a lot of "rich" it seems. Sometimes it stays high like that and doesn't drop down. That makes me think it's processing injector leaks or a partially stuck open injector.     Other times it looks like this. Nice oscillations between rich and lean, which is what I think it should be. Under load and at speed, the oscillations are nice and tight and uniform looking, high and low.     Fuel trims suggest the PCM is compensating pretty hard at idle to pull fuel out. But it's not enough to trip a CEL. Something about slowing to a stop: brake vaccum booster, EGR, or the EVAP purge is delayed, or there's pooled fuel in the intake again that's draining into a cylinder is enough to set the CEL. Of course, in two days of driving, it hasn't set. I was hoping to actually look at the freeze-frame data when it sets. IAT is high because it's idling on an 83 degree day here.  
    • Have considered installing a DC to DC charger in your camper to replace your isolator?  
    • Common failure.  You need to replace the fuel door housing.   The painted cover transfers over to the new housing.  To remove the old one there is 4 spots where you poke the plastic to release it.  
    • No such thing as regenerative braking on a pure ICE vehicle.     Regenerative braking is the re-capture of energy from electric motors and stores it in the battery pack.  So hybrids, PHEV and EVs have regenerative braking.     What you are seeing is the charging system changing modes is all.  Its likely entering charge mode for some sort of reason is all.  All of the charging modes will be listed below.   As for L10 vs D.  L10 turns off automatic grade braking.  L10 puts you in control of grade downshifts where in D it will automatically do it based on brake pedal position and other factors.  Otherwise L10 and D drive exactly the same aside from that one aspect.    Battery Sulfation Mode The BCM will enter this mode when the interpreted Generator output voltage is less than 13.2 V for 45 minutes. When this condition exists the BCM will enter Charge Mode for 2–3 minutes. The BCM will then determine which mode to enter depending on voltage requirements.   Charge Mode The BCM will enter Charge Mode when ever one of the following conditions are met:   Windshield wipers are ON for more than 3 s. Climate Control Voltage Boost Mode Request is true, as sensed by the HVAC control module via serial data. High speed cooling fan, rear defogger, and HVAC high speed blower operation can cause the BCM to enter the Charge Mode. The estimated battery temperature is less than 0°C (32°F). Battery State of Charge is less than 80%. Vehicle speed is greater than 145 km/h (90 mph) A current sensor malfunction exists. System voltage is determined to be below 12.56 V When any one of these conditions is met, the system will set targeted generator output voltage to a charging voltage between 13.9–15.5 V, depending on the battery state of charge and estimated battery temperature.   Fuel Economy Mode The BCM will enter Fuel Economy Mode when the estimated battery temperature is at least 0°C (32°F) but less than or equal to 80°C (176°F), the calculated battery current is less than 15 A and greater than −8 A, and the battery state-of-charge is greater than or equal to 80%. Its targeted generator output voltage is the open circuit voltage of the battery and can be between 12.5–13.1 V. When fuel economy mode is active, the generator is not charging, only maintaining open circuit battery voltage. The BCM will exit this mode and enter Charge Mode when any of the conditions described above are present.   Headlamp Mode The BCM will enter Headlamp Mode when ever the head lamps are ON (high or low beams). Voltage will be regulated between 13.9–14.5 V.   Start Up Mode When the engine is started the BCM sets a targeted generator output voltage of 14.5 V for 30 s.   Tow/Haul Mode (if applicable) Pressing the Tow/Haul Mode button located on the center stack, the vehicle system voltage is raised and the remote (non-vehicle) battery will be charged. Having the headlamps on will raise the system voltage and if the Tow/Haul button is applied it will not serve any purpose. The voltage is regulated between 13.9-14.5 V.      
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...