Truck not level

[WindyCityPilot]

I've had my '06 Silverado Z-71 Ext. Cab for about a month now. I noticed the other day when walking up to the truck from behind that the left side is noticeably lower than the right. I have not measured the difference yet but I was wondering what the factory tolerance is. Is this something I should have the dealer look at? Also how should I measure this? From the ground to the wheel well lip? Or in another way?

 

My last truck ('95 S-10) was also lower on the left side but not nearly as noticable as my Silverado.

 

Thanks in advance GM-Tech!

[GM-Tech]

This is VERY common. All our pickups are lower on the left side. Side to side allowable height difference is 1/2".

 

Here's a TSB on the concern...

 

 

Subject: Vehicle Lean - Left Front Sits Low or Right Rear High (Add Spacer Between Left Rear Spring Pack and Axle) #06-03-06-005 - (09/19/2006)

 

 

 

Models: 1999-2007 Chevrolet Silverado (Classic)

 

1999-2007 GMC Sierra (Classic)

 

with Two-Wheel Drive

 

 

 

 

--------------------------------------------------------------------------------

 

Condition

Some customers may comment that their vehicle appears to lean. In most cases, the vehicle will sit low left front or high right rear.

 

Correction

Measure fender wheel-opening heights, front and rear, to quantify vehicle lean. Fender wheel-opening heights are related to, but distinct from, trim height (a.k.a. Z and D height). The front wheel-opening height is known as P height, and the rear wheel-opening height is know as R height. The P and R heights are not set at the factory, nor is a specification given for them. However, they are the most direct and repeatable measurement of what a customer would see as the vehicle leaning. Perform the following before measuring the fender wheel-opening heights:

 

• Make sure the vehicle is on a level surface, such as an alignment rack.

 

• Set the tire pressures to the pressure shown on the certification label. Refer to Label - Vehicle Certification in General Information.

 

• Check the fuel level. Add additional weight if necessary to simulate a full tank.

 

• To ensure proper weight distribution, make sure the rear storage compartment is empty.

 

• Close the doors and hood.

 

P Height and R Height Measurements

P height and R height are measured the same way. They are the distance from the ground to the highest point on their respective wheel-opening, going through the center of their respective wheel. Record the measurement on the repair order.

 

If the difference fromleft to right for P and R height is 15 mm (0.59 in) or less, no repairs are suggested as the vehicle is within specification. If the difference exceeds 15 mm (0.59 in) for either measurement, install the spring spacer to the left rear side of the vehicle following the procedure below.

 

Raise and support the vehicle.

Support the rear axle.

Remove the U-bolt nuts, remove the U-bolts and anchor plate. Discard the U-bolts. DO NOT discard the nuts or anchor plate.

Remove the lower shock nut and bolt.

Raise the vehicle or lower the axle enough to allow for installation of the spacer. Install the spacer, P/N 15872657.

Lower the vehicle or raise the axle.

Install the lower shock nut and bolt.

Tighten

Tighten to 95 N·m (70 lb ft).

 

Install the anchor plate, new longer U-bolts, P/N 15872655, and nuts.

Tighten

Tighten the nuts to 72 N·m (53 lb ft).

 

Remove the axle support and lower the vehicle.

Re-check the P and R heights in the previous location. Record these readings on the repair order.

After all measurements are done, perform a road test and check headlight aim.

If these steps do not resolve the condition, please contact GM TAC for further diagnostic assistance.

 

Parts Information

Part Number

Description

Qty

 

15872655

Rear Spring Spacer

1

 

15872657

Rear Spring U-Bolt

2

 

 

Warranty Information

For vehicles repaired under warranty, use:

 

Labor Operation

Description

Labor Time

 

E9439*

Add Spacer to Left Rear Spring Pack (Includes Checking Height Measurements)

1.0 hr

 

* This is a unique labor operation number for use only with this bulletin. This number will not be published in the Labor Time Guide.

 

 

 

 

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

 

 

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[WindyCityPilot]

Awesome! Thanks GM-Tech!

[WindyCityPilot]

One more question....I noticed the TSB said for 2 Wheel Drive. Does this also apply to 4 wheel drive trucks like my Z-71?

[GM-Tech]

Nope, doesn't apply, but those are much easier to correct. Just crank up the torsion bar on the left side a bit to compensate for the lean.

[WindyCityPilot]

Nope, doesn't apply, but those are much easier to correct.  Just crank up the torsion bar on the left side a bit to compensate for the lean.

 

<{POST_SNAPBACK}>

 

 

 

Would the dealer be willing to crank up the torsion bar to correct this? Or is this something that I'd be on my own to do?

 

Messing the the torsion bar would also require an alignment correct?

 

Thanks again for the quick response GM-Tech!

[GMguy99]

I just had my alignment done, and now the truck leans to the passenger side. I took a look under the truck and the guy that did the alignment lowered the torsion key on the passenger side.

[GM-Tech]

Nope, doesn't apply, but those are much easier to correct.  Just crank up the torsion bar on the left side a bit to compensate for the lean.

 

<{POST_SNAPBACK}>

 

 

 

Would the dealer be willing to crank up the torsion bar to correct this? Or is this something that I'd be on my own to do?

 

Messing the the torsion bar would also require an alignment correct?

 

Thanks again for the quick response GM-Tech!

 

<{POST_SNAPBACK}>

 

 

 

 

 

The dealer should do this under warranty IF it leans enough to be out of spec. Measure it yourself before you go in to see if there's over a 1/2" difference side to side. Most places are not that picky and will see there's a problem just visually, but if they want to be difficult and measure it they might say, "within specs."

 

Yes, at least toe should be checked and set if necessary after cranking up the torsion bar(s).