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Discussion Starter · #1 ·
Hey guys,

I have recently completed my mild truck build. I don't have clean pictures yet, but have run across what I think is an issue. My fender measurements are as follows:

Driver Front: 39.75"
Driver Passenger: 40.00"
Driver Rear: 39.50"
Passenger Rear: 38.50"

Background: 2011 1500 Silvedado 4x4 (non Z-71), 5.3L LC9, 3.42 gears, Corsa Sport cat-back exhaust, Airaid MIT, Fox 2.0 Coilovers up front at 2" from factory, Zone Adventure Series UCA's, Fox 2.0 0-1" lift rear shocks, 285/70R17 Duratracs on my factory alloys. 24,500 miles. She rides and sounds great!

I was measuring my fender dimensions to determine if I wanted 2" or 3" rear blocks to replace my factory blocks for a little bit more rake when towing. I know I would need shock mount extensions for 3" blocks, but currently leaning toward the 2" blocks anyway which stays within my 0-1" lift limits of my new Fox rear shocks.

What in the world would cause my rear suspension to be off by 1" from side to side? There are no funny noises and everything looks normal that I can see getting under the truck. I measured my fender wells with a straight tape at the center of all 4 wheels on level ground. My bed is unloaded - completely empty. I would expect .25" differences, no biggie to me, but the rear end has me stumped. Could the passenger leaf spring be fatigued? I bought the truck with 11,300 miles almost a year ago (Valentines Day 2014) and certainly didn't notice it then and I have yet to tow anything heavier than my 1448 steelhead boat and my bed full of fishing gear.

Thanks for the help!
 

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Sounds like something was installed wrong
 

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Discussion Starter · #5 ·
Sounds like something was installed wrong
Possibly, but it was only the Fox shocks out back. You can install them only 2 ways and I confirmed that they can be installed "can up" or "can down" with the 2.0 IFP shocks with Fox tech support. I havent installed any blocks yet. Switching out the cat-back exhaust didn't mess with any suspension components either.

If my right rear shock is bad, could it droop 1" and still ride well? I would think it would noticeably ride like crap if I had a defective shock on one side.
 

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Discussion Starter · #7 ·
GM Parts Direct has OEM leaf springs for between $99 and $150 depending on the code. I might just figure out which code for my truck and buy a replacement spring pack at that price! I can hear the stealership blaming the marginally oversize tires for the sag. I'll try the warranty route first at least...
 

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GM Parts Direct has OEM leaf springs for between $99 and $150 depending on the code. I might just figure out which code for my truck and buy a replacement spring pack at that price! I can hear the stealership blaming the marginally oversize tires for the sag. I'll try the warranty route first at least...
Take shocks off and see if it changes
 

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Shocks have nothing to do with height
The only reason I suggested it was the possibility of a bent shock mount. Very slim chance, but possible.
 

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DeepSouth Gangster
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The only reason I suggested it was the possibility of a bent shock mount. Very slim chance, but possible.
But even with a bent shock mount, it will have no effect on height. Stop trying to act like you know what you are talking about.
 

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But even with a bent shock mount, it will have no effect on height. Stop trying to act like you know what you are talking about.
Lol, and why do I not know what I'm talking about?

Do you have a better idea? I suppose a shock issue would provide an awful ride.
 

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My truck has a little difference in fender heights on the rear, except mine and most peoples are on the driver side where the gas tank is. I think im at like 42.75" up front and my driver rear is 41 and passenger is like 41.75 if I remember right. That is odd that the passenger side is sitting lower.
 

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DeepSouth Gangster
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Lol, and why do I not know what I'm talking about?

Do you have a better idea? I suppose a shock issue would provide an awful ride.
Because you keep suggesting the shock absorber will cause the 1" height difference.

My idea for the differences in the height has to do with the springs themselves. Perhaps during the manufacturing process they came from a different batch, while although there are standards to meet, the thresholds for "acceptable" can create different results on the vehicle. Or another scenario is the environment of which the truck has seen. Perhaps in the five years this truck has been on the road there have been instances the springs have seen that fatigue them individually at different rates.

Put a taller block in the lower side and let it roll.
 

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Because you keep suggesting the shock absorber will cause the 1" height difference.

My idea for the differences in the height has to do with the springs themselves. Perhaps during the manufacturing process they came from a different batch, while although there are standards to meet, the thresholds for "acceptable" can create different results on the vehicle. Or another scenario is the environment of which the truck has seen. Perhaps in the five years this truck has been on the road there have been instances the springs have seen that fatigue them individually at different rates.

Put a taller block in the lower side and let it roll.
A taller block on one side would drive me nuts. That big of a difference at 11k miles is crazy.
 

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dont just measure bed to ground
measure frame to axle tube
axle tube to ground
bed to center of axle
this will help figure out what the issue is
 

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Did you buy the truck new? Or have a Carfax run?

His issue won't settle out since he didn't do anything to the rear. I'd imagine spring fatigue like the others have mentioned. I'd probably start there.
 

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DeepSouth Gangster
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My '13 is 1" lower on the driver side. No worries. Just don't look at both sides at the same time. Problem solved.
 
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