The up and down of torsion bars

[Redshift]

I'll try to draw a mental picture of our front end using the face of a clock. (digital clocks won't work here).

Our lower control arm pivots on the frame just as the big hand on the clock pivots in the center of the clock. Point the control arm to 3 o'clock and put a wheel there. The torsion bar acts like the clocks motor except it try to prevent the arm from turning.

The stock setup allows the control arm and wheel to travel up from 3 to 1 o'clock and down from 3 to 5 o'clock. The torsion bar holds the control arm at 3 o'clock.

When we level the truck with the torsion bar we are moving the normal position of the wheel from 3 to 3:30 or 4 o'clock.

The range of travel doesn't change, it's still 1 o'clock to 5 o'clock. We have changed how much travel is available up and down in relation to how the truck sits.

Let's say there is a major hump in the road like a railroad crossing that we are going to hit at speed. With cranked torsion bars we have more ability to handle the approach, the suspension can compress from 4 o'clock to 1 o'clock. On the down side of the hump the suspension can only extend from 4 o'clock to 5 o'clock.

In all cases of torsion bar adjustment the range of wheel travel stays the same. Adjustment changes how much of that range is compression and how much is extension.

Changing keys or using heavier bars doesn't change the range of motion either. The stock setup has a limited amount of adjustment. Let's say it allows adjustment from 3 to 3:30. Changing the keys or bars may allow adjustment from 3 to 4 or 4:30.

Make any sense?

kw

[docopharm]

Makes sense to me  . There needs to be some kind of sticky topic on this. I think this subject is probably the most asked about in the forum.

[Naked AV]

This topic has been explored in depth at FullSizeChevy.com.  I suggest doing a search over there if you want to learn more.

[Alaska_AV.]

  Center of movement is not at 3. More like 1:45
Wheel movement is limited to around 3" up before hitting the bump stops. You can jack up the AV almost 6" before the wheels come off the ground. I recommend using a floor jack over the stock one, unless you have allot of time.



So if you install ford keys and go up 1 1/2 inch you'll be closer to the center of motion.

[MountainLife]

Hey for these ford keys you guys are saying above and beyond my stock keys being maxed out i could get an additional 1.5 inch lift?

What is the cost of these keys and cost of install or difficulty in doing it youreself, thanks!

[jt2500]

To my best knowledge, replacing the keys and or cranking the adjustment bolt on the stock keys will give you the same result.  The only added benefit to replacing the keys is that it gives you more adjustment room from the stock keys.  Some trucks have no more room on the stock key adjustment and therefore it is 100% necessary to replace them with a modified one to get more adjustment space.  

These keys can be purchased around 50-100 bucks.  The work can be done on your own, but you will need to get the truck re-aligned professionally

[MountainLife]

so i was able to hieghten my truck slightly by tweaking the bars.. i'd gain no more height out of swapping in ford keys?

thanks

[jt2500]

If your stock adjustment has some distance left, you should have enough to adjust to get the truck level, however most stock keys dont have engough distance to get it level.  Therefore you need to replace the keys to get more adjustment.  Be careful, what these guys are talking about above is once your keys are cranked or replaced and the truck is level, the shock then becomes the bump stop in your suspension.  What that means is if you hit a bump or pothole or off roading, and your suspension needs to preload, there is nothing stoping the shock from over extending its self.  When that happens, you blow out your shocks.  THerefore, it has been recomended in the past to replace the stock shocks with ones that have better "re-bound valving" to slow that down and pervent them from over extending.  I have my 2500 leveled perfectly with the stock keys, but have blown my driver's side shock out.  I have just purchased two Rancho shocks that are going on this week.  These shocks are slightly longer in length and have better "re-bound valving".

[RichUF]

This topic has been explored in depth at FullSizeChevy.com.  I suggest doing a search over there if you want to learn more.

came across this during some research, so thought I'd post directly to it for those too lazy to search  

http://www.fullsizechevy.com/fscu/fordkeys.shtml

[CrazyTed]

Ford list price for the keys is $24.66 ...

[chaoticTiger]

When you measure the lenght of the tread you have left (adjustment) and multiply it with 2 1/2 than you know how much can go higher or lower with the torsian bar!

[jkhonea]

Speaking of torsion bars and keys, I've seen several kits with new torsion keys AND spindles.  Is it necessary to replace the spindles along with the keys if you're only lowering the front 2"?  Also, willl the front shocks still work with the front lowered on a Z66.  I know the back will need the McG shock adapter for a 3" drop but wasn't sure about the front.  Any help would be appreciated before I order anything.

[brad59]

Hey Guys
Be sure to get the wheels aligned after any adjustments up or down. The adjustments will change camber and toe which will wear out tires fast and at $150+ a tire we don't need that
Brad in KC 

[Shanes 02 Avalanche]

I have a lot of room in my Torsions for adjustment. I have leveled my Av out and still have about 2 inches of lift left. I also recommend the Rancho Shocks, I blew out both of my front shocks, which made one hell of a mess. I installed the Rancho's which was about 1/2 hour of work. Make sure to get an alignment otherwise like posted earlier you will eat your tires up.

[pontee94]

i wouldn't mess with them. doesn't that affect the CV angles?

[burritoboi5]

It depends on how much you mess with them.  I'd go body lift before torsion for that reason.

my .02

[02 snapalanche]

JUST WANTED TO ADD THAT I WAS AN ALIGNMENT/FRAME TECH FOR 12 YEARS AND I USED TO CRANK T-BARS ON A DAILY BASIS-NEVER HAD A COMPLAINT OR PROBLEM BY THE ADJUSTMENT-EXCEPT YOU NEED LONGER SHOCKS IF YOU GO MORE THAN 1.5-2 INCHES-SEEN LOTS OF SHOCKS COME APART(AFTER 99 YOU DON'T GET MUCH ADJUSTMENT ANYWAYS)AND IT REALLY CHANGES THE ALIGNMENT-THE FACTORY CALLS IT A "Z-HEIGHT ADJUSTER"

[burritoboi5]

JUST WANTED TO ADD THAT I WAS AN ALIGNMENT/FRAME TECH FOR 12 YEARS AND I USED TO CRANK T-BARS ON A DAILY BASIS-NEVER HAD A COMPLAINT OR PROBLEM BY THE ADJUSTMENT-EXCEPT YOU NEED LONGER SHOCKS IF YOU GO MORE THAN 1.5-2 INCHES-SEEN LOTS OF SHOCKS COME APART(AFTER 99 YOU DON'T GET MUCH ADJUSTMENT ANYWAYS)AND IT REALLY CHANGES THE ALIGNMENT-THE FACTORY CALLS IT A "Z-HEIGHT ADJUSTER"

My ears hurt.  Can we avoid the caps lock next time please.   

[woof]

Everything that I have heard and tested is that just cranking on the torsion bars affects the ride/handling.  I had these installed and am very happy:

http://www.suspensionmaxx.com/

[burritoboi5]

Interesting looking product 

[butterfingarz]

I have been thinking about doing this and looking over for some time now. I just put new ranchos shocks on all 4 corners. Id be happy at 1.5" lift in the front. Iam mechanically inclined to do the ford key swap myself. But i have heard things like do it dont do it. so i need to know IS IT OK??? Now my truck has 156k on it and am worried about what people say will wear out your CV joints. I think the ranchos ride alot harder than my old bilsteins and i am worried about ride quality as well. But i HATE the look of the nose down.

I understand that GM didnt want to have the back squat down when towing but common most people dont use the bed to haul X mounts of lbs daily. Dumb idea.

[Alaska_AV.]

The cv's are the best part of the front end.

IMHO they can take more than their asked to do.

 I just replaced all my ball joints and tierod ends, those being the weak links. Stock shocks being the worst part. BTW all 8 parts cost me $82 shipped to Alaska.

try it, you can allways go back to stock....

[eggmass]

Hey, JT2500, did you do the work yourself? If not, who did it for you? We met at the Hot Dog run a couple of years back, and I work with Eldy H.

If you could let me know who you trust locally in NJ, I would appreciate it.

[mrrevsss]

Well for what it's worth this is my expericience.
I have a2002 1500 with a fabtech 6" lift and 35" tires.
I rub a little going around corners and jumping sund dunes at Silverlake.
I decided to add the fords keys to get 2" inches of clearance.
On Friday i ordered the key from ford dealer for 50.00 got em Thurs had muffler shock shop install them for 50.00. I know i have  all the room I need.
I wish I would have done this a year ago.

[Lord Aries]

I have said this in others threads and thought would just say it again... Keys do NOT really get you more tire clearence, they just change the resting point of the suspenssion. If the tires rub at full compression before the keys, they will still rub at full compression after the keys.

Also, when doing this you really should space the front Bump stops down with washers because they are meant to be in contact with the lower control arms at the resting point. They are a part of the total spring rate of the front suspession.

Just and FYI...