Rear Axle Off Center?

WeGone · August 23, 2021

Ohh Snap mine is also off to the right... Guess I'll just have to drive it until the wheels fall off.

JimCost2014 · August 23, 2021

On 8/23/2021 at 2:20 PM, EricTheRed said:

GM released a TSB for their customers to drive around with a blowup doll filled with sand in the passenger seat which offsets the weight difference and keeps everything kosher.

Hmm, that reminds me of a joke about a deceased "lady of the night" filled with......

I will leave it at that

Edited August 26, 2021 by JimCost2014

Anacortes Army Guy · August 25, 2021

On 8/22/2021 at 5:10 AM, Diamond817 said:

I have a 2021 Silverado 1500 RST, 5.3, 8spd, 4x4, crew cab, short bed, 22" factory wheels. A couple days ago I noticed that the passenger side rear wheel is just about flush with the wheel well while the driver side wheel is recessed some. I went around a looked at few other new body style Silverado's and noticed this to be the case on all of them. Anybody else notice this? And why the hell would the rear axle be offset like this? it has to be close to an inch difference between sides. It bugs me, I don't like it.

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On 8/22/2021 at 11:40 PM, EricTheRed said:

Are you sure the bed isn’t misaligned?

Okay, after being unable to sleep since the OP started this thread, I took a close look at my LT today and identified the issue for MY truck. When looking down the side of the bed, along the crease/bend (whatever you want to call it) in the sheet metal located just below the 4X4 decal, it's clearly obvious that my bed is sitting approximately 3/8" off-center to the right relative to the back end of the cab. So in MY case, the bed is not centered on the frame and has nothing to do with the positioning of the axle.

gemarsh · August 25, 2021

10 hours ago, Anacortes Army Guy said:

Okay, after being unable to sleep since the OP started this thread, I took a close look at my LT today and identified the issue for MY truck. When looking down the side of the bed, along the crease/bend (whatever you want to call it) in the sheet metal located just below the 4X4 decal, it's clearly obvious that my bed is sitting approximately 3/8" off-center to the right relative to the back end of the cab. So in MY case, the bed is not centered on the frame and has nothing to do with the positioning of the axle.

There is a TSB out for the misaligned bed. I followed the directions on the TSB and did it myself, as I didn't want the truck in the dealers body shop, after stopping by.

The body shop manager never heard of it. Gave him a copy of the TSB. He went out to his T1 and it was misaligned.

Anacortes Army Guy · August 25, 2021

27 minutes ago, gemarsh said:

There is a TSB out for the misaligned bed. I followed the directions on the TSB and did it myself, as I didn't want the truck in the dealers body shop, after stopping by.

The body shop manager never heard of it. Gave him a copy of the TSB. He went out to his T1 and it was misaligned.

Thanks! For those interested in the TSB, here it is. I think I'll just live with it the way it is.

MC-10187389-9999.pdf

WeGone · August 25, 2021

From Frame to outside of tire This is my 2nd 2021 both have been the same 1st was made in the US this one Mexico.

1st photo Right

2nd Left

Edited August 25, 2021 by WeGone

SilveradoRST · August 25, 2021

Any longterm effects such as uneven wear or stress on the mounting points, if I leave it misaligned? Silly question but, is the misaligned bed still within spec (loose tolerances?)

Diamond817 · August 25, 2021

So it looks like there are 2 things going on here. The axle is off center, and the bed is misaligned. Between the two it could make up to an inch of difference.

Anacortes Army Guy · August 26, 2021

6 hours ago, SilveradoRST said:

Any longterm effects such as uneven wear or stress on the mounting points, if I leave it misaligned? Silly question but, is the misaligned bed still within spec (loose tolerances?)

According to the TSB, assuming I read it right, the allowable tolerance is 2.5mm. I interpret this to mean that GM believes as long as the bed is within 2.5mm of center, it's good. Mine is off by maybe 3/8" or thereabouts, so I'm not going to worry about it. I don't see anyway this could have long-term negative affects on the truck.

Anacortes Army Guy · August 26, 2021

5 hours ago, Diamond817 said:

So it looks like there are 2 things going on here. The axle is off center, and the bed is misaligned. Between the two it could make up to an inch of difference.

On my truck it's only the one issue, addressed in the TSB. I'm unaware of another TSB dealing with any potential issue with the axle being off-center, but I guess there could be individual instances of that. Sufficient instances of bed alignment obviously exist, enough so that it caused GM to generate a TSB on the issue.

Acpantera · September 1, 2021

I measured from the frame rails to the rims, my axle is 3/8" to the right. I thought I'd ck if the axle was centered on the springs. I measured from the caliper mounts to the outer edge of each spring, exact measurement on each side, so it appears the difference is in the springs, spring bushings and/or the spring hangers. My guess would be the difference in how far the spring bushings are pressed into the springs. My truck goes straight down the road with no pull to either side and the steering wheel is straight, so I'm not really concerned.

fastk9dad · September 21, 2021

After detailing my truck this weekend I noticed both of these issues.

According to the TSB, assuming I read it right, the allowable tolerance is 2.5mm. I interpret this to mean that GM believes as long as the bed is within 2.5mm of center, it's good. Mine is off by maybe 3/8" or thereabouts, so I'm not going to worry about it. I don't see anyway this could have long-term negative affects on the truck.

I measured my truck and the drivers side has the cab 6mm off from the bed (noticeable) and the pass side is 4mm off (visually looks spot on). So like you I'm not going to mess with it as it is within tolerance and 1mm isn't worth it.

I did also noticed that bed to cab alignment is slightly off my 1/8" from drivers to pass. Not enough to visually detect over the length of the cab but it was just something I noticed while I had the tape measure out.

I measured from the frame rails to the rims, my axle is 3/8" to the right. I thought I'd ck if the axle was centered on the springs. I measured from the caliper mounts to the outer edge of each spring, exact measurement on each side, so it appears the difference is in the springs, spring bushings and/or the spring hangers. My guess would be the difference in how far the spring bushings are pressed into the springs. My truck goes straight down the road with no pull to either side and the steering wheel is straight, so I'm not really concerned.

Like others have noticed the passenger rear wheel is about 3/8-1/2" further out than the drivers side. While that seems like a lot it's less than 1/4" of axle movement from side to side. What I have also noticed is all the trucks I've seen this visually sit with the passenger side slightly lower (looking at the top of the tailgate) but a little bit. I'm wondering if the drivers side has a higher spring rate than the pass side which is contributing to the slight offset.

bpl0807 · December 6, 2021

I'm a bit late to this post but just measured my 2021 Trail Boss and my axle seems to be off by exactly 1/2" to the passenger side when measuring from the wheel to the frame rail. My bed is off by about 1/8" as well but very difficult to see with the eye. Truck seems to drive just fine so I'm not too worried but definitely something worth taking note of.

voided3 · December 8, 2021

On 12/6/2021 at 4:42 PM, bpl0807 said:

I'm a bit late to this post but just measured my 2021 Trail Boss and my axle seems to be off by exactly 1/2" to the passenger side when measuring from the wheel to the frame rail. My bed is off by about 1/8" as well but very difficult to see with the eye. Truck seems to drive just fine so I'm not too worried but definitely something worth taking note of.

Same here, the axle sits more to the passenger side. Our bed also was misaligned and the dealer fixed that as it was pretty significant, but like you, I'm not too concerned about the axle situation as the tracking and tire wear are normal for now.

8x180 · August 23, 2022

I am really late to this but wanted to add that my axle is also off 1/2-5/8 as well. The truck drives fine but it does bug me because it is enough that it catches my eye. My bed was off quite a bit and was fixed at the dealer.

I had called the GM help line and they gave me a case # and then the multiple people that were assigned to my case would never call or be available when I called. It was an obvious issue and they blew me off. They could not even speak with me and give some BS answer. It was so great to be treated that way after purchasing my first ever GM product. I was never treated that way by Dodge/RAM.

While at the dealer I looked at several new and used 1500's and HD's and all 1500's were off center and all of the HD's were even I guess no one has found an answer for what causes this and why GM won't own up and answer.