Replacing Torsion Keys vs Cranking Stock Keys

Replacing Torsion Keys vs Cranking Stock Keys

Key It or Crank It
No, this isn’t a blog about vandalizing someone’s truck, this is about your GM torsion bar IFS (Independent Front Suspension) equipped truck, and the difference between replacing the factory torsion keys, or cranking up the factory torsion keys using the torsion key adjusters.

Most people that own a pick-up truck understand that when you buy a new stock truck it comes slightly higher in the rear. I’m going to use full size GM Trucks as an example, but there are other torsion bar equipped trucks out there that this may apply to. There is usually about a 1.5” to 2” difference in height in the rear when compared with the front suspension. This is where the term “leveling” your truck comes from.

An owner usually wants to level his or her truck to match the factory height in the rear. This is accomplished in a few different ways, and with a combination of parts to help with proper alignment and ride quality, but the two most common, and least expensive, ways are by either adjusting , or “cranking”, your stock torsion bar key adjusters, or doing a torsion key install with aftermarket leveling keys, and then adjusting them. Either way will give you similar results.

Cranking Factory Torsion Bars – Pros and Cons
The first and easiest way to level your IFS/torsion bar equipped truck is by “cranking,” turning the torsion bar key adjuster bolts under your stock torsion keys on each side of your truck. Some truck models will allow for more of an adjustment than others, and with those trucks you might be able to get your truck just as level as swapping out the keys.

To do this, look for the 2 torsion keys.
GM-Torsion-Key-Location

Under those keys you will find a hex bolt on each side.
GM Torsion Key Hex Bolt Location
Turning that bolt in or out will either lift or lower your front end by raising or lowering the torsion key which turns the hex ends of the torsion bars, and subsequently does the same to the lower control arms on the other end of the torsion bars…it lifts or lowers them.

A big misconception here is that this will change the spring rate of the torsion bars, but that is not true. Yes it will make your truck ride worse than it did stock, but this has more to do with the over extension of the shocks and upper control arms, not with the torsion bars.
This process is simple, and if you do the work yourself it will cost you nothing to gain some extra ride height and tire clearance.

Unfortunately, the cost is the only upside to doing it this way. The downside to this setup usually means that you are maxing out the adjusters until they are bottomed out, compromising ride quality due to over extension of the shocks, upper ball joint misalignment, limited down travel of the upper control arms, and usually you will not get the desired height increase you want.

Installing Aftermarket Torsion Keys
Another way to Level your IFS/torsion bar equipped truck would be with new aftermarket torsion keys, or what they call leveling keys. The difference with using a set of leveling keys to raise the front of your truck is that it gives you more height adjustment.

This is accomplished by the redesign of the torsion key itself. If you stacked the stock key on top of the leveling key you will notice that the long end of the torsion key is in a different position when you line up the hex shaped hole where the torsion bar end would go through.

Stock vs Aftermarket Torsion Keys

This allows the torsion bar to be re-positioned slightly so that when the adjuster bolt is turned back to the position it was originally at before you removed it, the height of the front suspension would now be higher without having to crank up on the adjuster bolt as much. This allows for more lift, but it will not solve any of the ride quality issues, or suspension alignment issues.

Also keep in mind that there is a limit to how far you can raise the front end, especially on a GM truck. You will notice on some models of GM trucks, under the upper control arms there is a bracket or bump stop that is part of the upper control arm pockets that limits the down travel, or droop, of the upper control arm. The more you raise the front of the truck, the more the upper control arm angles downward, and the closer the control arm gets to this stopper.

The trick to getting the most lift out of your new keys without bottoming the upper control arms out or losing down travel of the suspension completely is the distance between these two points.

Rule of Thumb
Ideally you should be able to just about get your thumb between the bottom of the upper control arm and the top of this bracket or stopper. I found this is to be the sweet spot. It might not put the truck level, but you will still have enough travel to give you a decent ride. You can always decrease this distance even more to get a higher stance, but you will be sacrificing more of the ride quality and down travel the higher you go.

Always check to make sure your ride height is equal on each side. So measure, adjust, cycle the suspension, measure, and repeat until you get the ride height you want, and the proper side to side measurement.

Bottom Line
By using aftermarket leveling keys, you gain more height adjustment with some GM truck models, but the ride quality will still be same whether you use the stock keys or the new leveling keys.

For those of you who have it in the budget, fortunately there are leveling kits out there which come with all the necessary components that will increase the longevity of your suspension, help with ride quality, and keep the proper alignment of your suspension components. These kits will include new aftermarket upper control arms, new aftermarket shocks designed for the increase in lift, and leveling keys.

I highly recommend purchasing a full leveling kit with all the necessary components if possible. I do understand, however, that it usually comes down to your budget. For the least expensive solution, look at cranking your stock torsion bar key adjusters. For more height adjustment, go with the aftermarket torsion key install.

And no matter which solution you decide upon, always get your truck aligned afterwards.

Here are some leveling kit options specifically for your Duramax:

Duramax 2001-2010 Leveling Kit (leveling keys w/shock spacers):
Daystar KG9107
(Fits Vehicles Equipped with Purple, Blue, Brown, or Yellow marked Factory Keys)

Daystar KG9114
(Fits Vehicles Equipped with Orange, Green, or White marked Factory Keys)

OR
Tuff Country 12904
(Fits Vehicles Equipped with Orange, Green, or White marked Factory Keys)

Tuff Country 12944
(Fits Vehicles Equipped with Purple, Blue, Brown, or Yellow marked Factory Keys)

OR
ReadyLift 66-3050

Duramax 2011-2016 Leveling Kit (leveling Keys w/ Spacers):
ReadyLift 66-301

Other ATP Leveling Kits

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