Newbs are so stubborn about defending leveling kits...STOP TRUSTING WHAT YOU READ IN THE ADVERTISEMENTS FOR THESE KITS

 

Why do you need a wheel alignment after you crank the torsion bars?

 

Because you are changing the perpendicular angle of the wheel in relation to the road. In other words, your tires will wear out much faster than normal.

 

There is an actual torsion bar key you can get which allows for more height without losing the ride. (which is what I thought I ordered)
Incorrect. The stock key does the same thing as any re-indexed key, as Bunger said, the maximum height of 23.5-6" is the max, no matter what T Bar Key you are using. All you are doing is changing the position of the T Bar.
The problem with torquing the bolt for your torsion bar key is, what others are saying here, it takes away from the smother stock ride. The torsion bar is your spring... Which works by twisting it instead of the up and down type of spring.
Changing the position of the T Bar, does NOT change its spring rate therefore your "ride" does not change.
When you begin tightening that bolt it begins to twist that torsion until it begins to lift the front of your vehicle.
Exactly, that is why you do not need a spacer, re-indexed key or leveling kit.

You are right and wrong.

WRONG: It does change the spring rate, and it does effect your "ride." It's a night and day difference.

It changes because as it twists it gets harder to twist, (the spring rate changes) So if you twist it to raise your front end... It make for a rougher ride.

If you ever try this you will notice the more you tighten the bolt, the harder and harder gets to tighten, because the spring rate is changing on every turn.

It's not like stock coil springs... Where you can just keep pushing them until they bottom out. It's more like ringing out a towel... The more you twist it the harder it gets, and since you began loading your springs trying to lift the front end up. You are actually changing the rate of spring.



RIGHT: I didn't realize it until you wrote it out... But you are right, it probably won't make a difference even with a new torsion bar key. (which I'm glad you wrote that, because I was about to waist more money on that) Same concept... Just with a different torsion bar key.

Thanks!!!

 

That is actually incorrect, but in your defense, many folks think that is the way a torsion bar works. In actuality, the spring rate doesn't change, it only makes your control arm slant down to a more perpendicular angle to the road which is the greatest cause of a rougher ride after adjusting the bars. The more perpendicular the control arm angle, the rougher the ride.

The torsion bar is in fact twisting when under load, but by adjusting it ,it is not twisting to any greater significant degree than the factory setting . You are simply moving both ends to the same degree by tightening up one end.

Theoretically it seems like it would be twisting more by 'cranking' it to create lift, but the rotational tensile strength of the bar is much stronger than a small degree of CA angle could affect to any measureable degree. I doubt you'd even be able to physically measure any additional rotational torsion with a micrometer.

Here's an article that supports your thought but in reality is actually incorrect:

Off-Road IFS Truck Torsion Bar Basics - 4-Wheel & Off-Road Magazine


Here's a good explanation that is correct: GM Torsion Bar 401


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I think you may want to read the GM torsion bar 401 because it actually said almost exactly what I wrote. Here I will copy and paste for you.

To define how a torsion bar works we can compare it to other springs. A coil spring uses compression and extension and depending on the design of the spring can be a linear, step linear, or a progressive rate spring. A leaf spring uses flex and is a progressive spring. The torsion bar on the other hand uses resistance to torque and is a linear spring. A torsion bar is essentially a steel bar with some form of splines on each end. On our GM torsion bars it’s not the type of splines you are used to, like what you would find on an axle shaft, but instead a hexagonal head, similar to a bolt head. In fact you can slide a socket over it if you have a big enough one. Now when one side is fixed to an immovable object and the other is twisted, torque is applied. The torsion bar resists this torque and like any other spring it returns to its original position when the torque is let off. Now let’s apply this to our trucks. The immovable object is going to be our frame, or rather the torsion bar cross member on our frame where the torsion bars are anchored. The other end is connected to the lower control arm (LCA). The LCA pivots on a fixed point on the frame and creates twisting motion on the torsion bar – the torque needed to make it a spring. For example, when the vehicles front suspension compresses, the LCAs move upwards and exert force onto the torsion bars, so they push back onto the LCAs, just like a coil or leaf would.

And as I said it does effect they ride... Again copied and pasted for you from your own page you refereed to.

Now that you have a basic idea of how a torsion bar works lets discuss why it is what GM chose for our 4wd suspension. One answer is that it is cheap and maintenance free. Some torsion bars do use bushings that need greasing on other vehicles but GMs do not. Second, they are out of the way. A leaf spring can’t be used on IFS and a coil is in the way of the half shaft used to transmit power to your wheel in the front. The torsion bar is totally out of the way. Finally, it is adjustable. The fixed end of the torsion bar that is anchored in the torsion bar cross member is anchored into a “key” which can be turned with an adjusting bolt, therefore effecting the resting position of the LCAs and the height of the front of your vehicle. Sounds like the perfect suspension doesn’t it? Not quite. The fact that torsion bars are a linear spring effect the ride quality in a negative manner.

The key words you must be missing is linear spring, and the word anchored. (which means one side doesn't move)
The linear spring... The more you twist it the harder it becomes to twist. You are in fact twisting the torsion bar, which is causing, as you said, "your control arm slant down to a more perpendicular angle."

I actually got under the Hummer last night and watched it work. I turned the torsion bar key bolt probably 15 times before is began to start raising the front end. Not only that, I marked a straight line on the torsion bar before I began turning it. Guess what... It was twisting, and the anchored part, (the torsion bar key) stayed in the same place, it was just twisting the torsion bar, which was raising the from end.

 

I installed the Truxx Lift level kit several months ago. Works like a charm. Here's why its not a waste for $60.00. First of all without the spacers that go on the torsion bolt, the bolt tops out against the floor pan. Take a look as you tighten it. Only gives you about 23 -23 1/2 lift when it tops out. You need 24 1/2 to match the rear and to level the front. Per Truxx 24 1/2 is fine and will not cause any damage to your suspension or cv joints. So with the spacers you can easily lift to 24 1/2 and 25+ if your not careful.

As for the shock extensions that come with the kit, they allow you to use your oem shocks and keeps them working at the same range they were at before you lifted. If not, your working them more extended and they tend to top out and ride will feel stiffer. I know some folks will go with extended Bilsteins, at a much higher cost.

Additionally, the kit gives you very specific specs on lifting to the 24 1/2 and also includes modified alignment specs that have been calculated by Truxx for the lifted leveleld vehicle so you can have it aligned to their specs at the front end shop.

Like I said in my experience not a waste of money by any means. Tires were properly aligned to the Truxx specs and ride just as smooth. Looks great leveled with some 305-55-20 all terrains. (equal to 33's). Even tire wear after several thousand miles.

Best 60 bucks I ever spent and vehicle is truly leveled.

 

Gotta love the newbees who don't heed the advise of those who have done the actual modifications (just not reading about them). Some people have to make the mistakes themselves to learn. I do understand that.

I'd love to see how long he half shafts, bearings and seals last an H3 at 24 1/2". Oh that's right, it has been done and they didn't last too long.

 

So you turned the bolt 15 times before it changed the ride height? And you could visibly see it twisting?

On my personal H3, I can see up to a 1/4 inch change in ride height with only one half of a complete revolution of the torsion key bolt after the torsion bar is at full torsional load. Perhaps you are confusing the wind up of of the torsion bar to get to full load to the properties of it after it is already at full load.
Keep in mind that the torsion bar isn't at full torsional load when the control arm is resting on the lower jounce dampner in the factory position. But once the bar has all the weight of the vehicle on it to achieve full load, the only result of further key-bolt adjustment is forcing the control arm down, or snapping the torsion bar itself. There is only so much rotational torsion available in a 1 1/2" diameter steel rod. Once it is near or at full torsion, the primary spring effect is in the linear property of the spring. Thus the reason it is called a linear spring.


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In a few months he'll be bringing up old threads on half shaft replacement and busted steering racks, wondering what went wrong.