For some reason my torsion bars arent cranked evenly. the front is level, and the passenger rear sits about an inch higher than the driver rear. im hoping my frame isnt twisted! any ideas of what it could be? thanks - bowtie
For the torsion bars, I don't think this is unusual for one to be slightly weaker than the other. I've seen this mentioned on GMTC before.
The RR being higher than the LR is what's commonly referred to as the Chevy/GM lean. There's a factory fix, or a factory approved fix for that. Enter lean in the search box above cuz somebody posted the parts & the fix about 2 weeks ago.
Congratulation, your truck is normal. LOL. The adjustment screws for the t/bars is to level the truck from SIDE to SIDE. You have the fuel tank on one side. GM uses differant spring rate t/bars to adjust the fronts at the factory. People just started cranking them up as a cheap way to level the truck. GM makes about 20 differant t/bars. I put what is known as the "WZ" bars on the front of my truck because of my winch and grill gaurd. They come on alot of 3/4 ton trucks.
I found it Bowtie. This info was posted courtesy of Mike Heartbeat in response to another "Chevy lean" inquiry.
My Truck also Sat lower on the Driver-side than the Passenger-side.........its called the Chevy Lean,
Below is a G.M. Service Bulletin Regarding the......Vehicle Chevy Lean, Subject Vehicle Lean - Left Front Sits Low or Right Rear High (Add Spacer Between Left Rear Spring Pack and Axle) #06-03-06-005A - (01/12/2007)
Models: 1999 to 2007 Chevrolet Silverado (Classic) 1500 (½ Ton) series
Models: 1999 to 2007 GMC Sierra (Classic) 1500 (½ Ton) Series
With Two-Wheel Drive
This bulletin is being revised to update the models to reflect that bulletin only applies to 1500 (½ Ton) Series. Please discard Corporate Bulletin Number 06-03-06-005 (Section 03 -- Suspension).
.....Some Customers, Have commented 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 from left 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 to 95 N·m (70 lb ft).
Install the anchor plate, new longer U-bolts, P/N 15872655, and nuts.
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.
Part Information, Part Number....15872655 Description .....Rear Spring Spacer
Part Number....15872657 Description......Rear Spring U-Bolt
Part Number...15756770...is for a rubber insulator the dealers use to space the driver side coil spring.
....Side Note....If your left front is 1" lower , you can add one digit to your Part # that come on your truck and it will raise your left front approx 1"
Here are 3 other Truck Forum's.....that call it......the Chevy Lean,
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