The Gm Lean

[OldCrLvr]

OK guys today I lifted the rear of my truck 2" using a Superlift block kit. I am pretty happy except my unevenness got worse. Before the blocks I was 1" higher on the passengers side. Now I am 1.75 higher on the pass side. If you look at my leafs you can see the drivers side short leaf touches the other more than the pass side does. My question is what happened to give me the extra 3/4" lean? I went out on a drive for about 45 minutes to see if there would be some settling. There wasn't. Any insight?

[deerchooper]

i never seen these blocks but, most blocks have a wedge shape to them to give you proper pinion angle. make sure you have them facing the right way.

[Snow White]

1994 and up s10's had the lean, didn't think fullsize did though?

[00_Extended]

Bad or weak leaf spring and the block just multiplied what was wrong on the bad leaf. Take it to a spring shop and have them re-arch the spring that is low to even it out or get to new spring re-arched so you don't have to use the blocks.

 

National Spring in El Cajon Ca (near San Diego) if they are still there does this. You used to be able to drive in and drive out with new springs in a day or two custome made for your truck.

 

Also if you have done work in the front with arms and might have a tight one or uneven spring in front you may be causing this problem. Lift spacers in the springs, springs not seated in the pockets correctly or just crappy springs.

 

After doing any suspension work except the u-bolts the final torque should be done with the vehicle on the ground. Notice I said torque........you need/should o follow and use the correct torque specs. This is all just my opinion though....

 

Joe

[dlstewart01]

All the GMT 800s had the lean. There were a couple of GM Bulletins on it. I don't have them right now

Do a search....

[Visegrip117]

My 01 silverado had the same lean. Kind of annoying, but I just got use to it

[csheatz]

they all lean, mine is 1/2 higher on the passanger side back but not in the front? had a full tank of gas at the time so maybe that was it.

[prioritypest]

Never noticed a lean in my 09 but when I installed my rear airbags I had to compress the left side where the right side fit easliy. Only about a 1/4 tank of gas when I did the install

[amtz.zero]

I've noticed it. I think my truck has it, too.

[dlstewart01]

I learned a long time ago, the worst thing you can do is take a tape measure to your truck. Then you will worry about it forever. Mine leans some, I don't worry about it. If it is on perfectly level ground its not that noticeable. Unlevel ground makes it worse.

 

Either don't worry about it or get a fat chick for a girl friend...

 

 

On 4X4s the front torsion bars can be adjusted to take some of it out..

 

 

Here is one of the bulletins...

 

 

Models: 1999-2007 Chevrolet Silverado (Classic)

 

1999-2007 GMC Sierra (Classic)

 

with Two-Wheel Drive

 

 

 

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

 

ConditionSome 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

 

I bought one of these spacers. Its still on the shelf in the garage. I just quit worrying about it...

[dlstewart01]

Another one...

 

Subject: Left Front of Vehicle Sits Low - keywords alignment appearance body fender spring suspension #PIT3281A - (12/13/2005)

 

 

 

Models: 1999-2006 Chevrolet Silverado

 

1999-2006 GMC Sierra

 

2 Wheel Drive Models Only

 

 

 

 

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

 

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

 

Condition/Concern:

Left front of vehicle sits low.

 

Recommendation/Instructions:

Measure front trim height keeping in mind that the trim height tolerance is .5" difference side to side. Verify that the vehicle is equipped with the correct production front springs. You should measure the standing height of both front springs to ensure that they are equal height. Check "z" height measurements as per SI. After determining that the above checks do not influence the concern, install a front spring upper insulator, P/N 15756770 in the lower control arm spring pocket. Install 1 insulator at a time and measure the change between installations. A maximum of 2 insulators per spring pocket may be used.

 

Please Note: The steering alignment and headlight aim must be checked if the vehicle ride height was changed.

 

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

[Z'06]

With a full gas tank, my Tahoe is 1/2" lower on the rear left than the rear right. It's never been visually noticeable, before or after I added Ford keys and rear coil spacers.

[OldCrLvr]

Terry, you are right. They do have a taper to keep your drive line angle correct. I have triple checked them to see if one was in backwards. Unfortunately one isn't.

 

Joe, The drivers side spring pack is sagging. It is noticeable to the naked eye when looking at the small bottom spring. The original owner used it for towing her 5th wheel horse trailer so it has had a lot of weight applied the first 9 years of it's life. I did do the torqing of the U bolts on the ground to the new specs which was 85 lbs.

 

Don, thanks for the tech. I didn't realize there was a spacer "fix" it's good to know. It didn't bother me before but now that it is 2" (after it settled it went up another .25") it is noticeable. I will most likely just live with it.

 

Thank's for all of your insight's

[jblakeney]

HAHA, never really loooked but im equal went and measured the bumper and wheel arch...... frt to are = and rear is off a little like 1/8 inch but i have some new ballast in the truck and a couple cases of bulbs... Proly the same with out that stuff in the truck...... If it wasn't 26 freeeekn degrees outside I would have taken that stuff out and remeasured the back again.

 

Jbo

[jabo052]

Yeah...the passenger side on my '02 has sat lower on the driver side since the day I bought it, though I never really noticed it for almost a year. No big deal and it's about to get replaced with a '10 anyway.