Torsion bar fun

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sireland67

sireland67

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Installed a new set of 1.030 torsion bars when I rebuilt my front end.
I am having alot of trouble with ride height.

My stock torsion bars if you set them side to side with the hexagonal sides even, the other side is 30 Deg off, not in the same plane.

The aftermaket ones are completly even when you put them side by side, and in the same plane.

I am really sure I have a defective set of bars, I will call the manufacture in the morning.

Sorry to sound so complicated, but when you install the aftermarket torsion bars in the car you have two choices.

First choice the adjuster is the maxed out and the car is on the almost on the bump stop.

Second choice push the lower control arm down as much as
possible with no adjustment on the bolt you have at least 4" of height from the top of the tire to the fender.
This binds the upper control arm.

Does anybody have a set of aftermarket or original torsion bars laying around to compare.

Thanks
 
I just checked my original bars from a '68 318 'Cuda just to verify this for you. The hexagonal ends are not in the same plane and 30 degrees looks about right. I believe they are manufactured with the offset for pre-load.
 
I have a set of PST 1.030 torsion bars arriving for my 71 Demon in a few days...it will be interesting to see if I have the same issues as you...will post you back when I know more information...I do have the slant six bars I could look at to compare...James
 
Thanks guys for the input.
I did not have time to call the manufacture today, but something is not right.
I will update when I have more details.

James, these are Hotchkis 1.030 bars, hope you dont have the same problem.
 
Emeraldart said:
I have a set of PST 1.030 torsion bars arriving for my 71 Demon in a few days...it will be interesting to see if I have the same issues as you...will post you back when I know more information...I do have the slant six bars I could look at to compare...James
Click to expand...


Please let me know if they have the offset or are straight.
Thanks
Shawn
 
FISHBREATH said:
I just checked my original bars from a '68 318 'Cuda just to verify this for you. The hexagonal ends are not in the same plane and 30 degrees looks about right. I believe they are manufactured with the offset for pre-load.
Click to expand...

Thank you, this is the problem I am having.
There is no way to pre-load the suspension.
I will not make no conclusions until I contact the manufacture.
 
When I installed my 1.00" torsion bars from just suspension, i did not check to see if they were in the same plane. I believe the degree offset of the hexagonal ends is based on the spring rate of the torsion bar. It would obviously differ between the different bars based on the thickness, as this affects the spring rate.

I was able to set mine up by bolting in the LCAs, letting them settle all the way down (just above where they would hit the k-frame), and backing the torsion bar adjustment bolt all of the way out on the LCA (just enough threads left to securely be in the adjuster with no chance of later crossthreading it). I was then able to slide the torsion bars through the transmission crossmember and into their respective hex slots on the LCA. Both of mine lined up fairly well first try by doing it this way. However, I do not yet have a motor in the car, so measuring fender gaps and ride height would not help.

Good luck figuring out the issue. Hopefully the company will have some input.
 
Sireland67, still waiting for the PST bars to arrive...even though they are from a different manufacturer they should be nearly identical, as the diameter is the same....right now my LCA's are just sitting in the k-member loose and not tightened, this allows them to be at nearly the 6 o'clock position hanging down with the new Hotchkis HSS 14385 strut rods in place. It has to be LCA positioning and where they slide in at that point. Let me know what you find out and good luck. James

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Emeraldart said:
Sireland67, still waiting for the PST bars to arrive...even though they are from a different manufacturer they should be nearly identical, as the diameter is the same....right now my LCA's are just sitting in the k-member loose and not tightened, this allows them to be at nearly the 6 o'clock position hanging down with the new Hotchkis HSS 14385 strut rods in place. It has to be LCA positioning and where they slide in at that point. Let me know what you find out and good luck. James

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Click to expand...

I tore one side off of mine the other day and tried to put the bar in the next lower notch, it will go in but you cannot bolt the upper control arm in because it will bottom on the frame with the upper stop removed, even with the lower control arm sitting under a jack forcing it all the way up and picking the car off of the jack stands.

When I tried this I had the adjuster bolt all the way backed off and a C-clamp holding adjuster all of the way down.

Still have not had time to contact the manufacture.

Here is a pic of my suspension.
This is with the adjuster all of the way up. To me it looks like the suspension is about 30 degrees out of whack.
Notice the clearence on the lower bump stop.

I did drive the car, and beside the really low ride height, it does not bottom out and is nice and stiff.

1000527w.jpg
 
My PST torsion bars finally arrived...see photo...they do have a left and a right, but come with no instructions. I probably won't be able to try installing them until next week. They don't appear to have any offset either. I will post back when the 'fun" begins...were you able to contact the manufacturer for any insight or addition information? Your photo of the lower bump stop looks too low to my eye. Good luck and will post later with my results. James
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Yes my lower bumps are way low.
Are your bars both flat when you lay them side by side.
 
The stock Mopar bars have a 30 degree offset to create preload. However, they also have a MUCH lower spring rate.

I'm pretty sure that the Hotchkis bars are 0 offset bars, ie, no offset. But a 1.03" bar doesn't really need any offset to create preload, the bars are stiff enough by themselves. The Hotchkis bars will lower the car, but you should still be able to raise it up to stock height with the adjusters cranked all the way in. At least that's what Hotchkis told one of the members on th challenger forum, he wanted stock ride height and found it hard to get the car that high with the Hotchkis bars.

The PST bars may NOT be the same. The offset is set in manufacturing, so PST can choose to spec whatever offset it wants, 30 degrees, 15 degrees, 0, whatever. That offset does go a long way to determining ride height though, 1.03" bars with a 30 degree offset will put the front end up at 4x4 height. So ideally, the offset has to be matched with the spring rate of the bars.
 
The bars are marked left and right which indicates they aren't the same.
The reason is in the weight disribution in the vehicle, i.e. battery, driver, etc..
 
RedFish said:
The bars are marked left and right which indicates they aren't the same.
The reason is in the weight disribution in the vehicle, i.e. battery, driver, etc..
Click to expand...

Spring rates on the bars are identical, as are the offsets. They're marked left and right so that the offset is in the correct direction.
 
I had the same problem. I am also running 2" drop spindles. To get my ride height up where it needs to be I got a set of longer adjusters. I believe they came out of a b-body, and the heads are 13/16" if I remember correctly.
 
MrCuda68 said:
I had the same problem. I am also running 2" drop spindles. To get my ride height up where it needs to be I got a set of longer adjusters. I believe they came out of a b-body, and the heads are 13/16" if I remember correctly.
Click to expand...

Were they aftermarket or out of a Junk yard.
If they were aftermarket could you please give me the part numbers?
Thanks
 
I got one years ago from my brother in law, after a tire broke one. It was off of a b-body he does not remember what year. But it is a larger thread, 9/16" I believe and a little longer with a 13/16" head. When I chafed my torsion bars and had trouble getting the ride height correct I looked around and none of the junkyards around have anything older anymore. I found aftermarket ones online that work for a or b bodies. Here is the address, hope that helps.
http://americanmuscle.carshopinc.com/product_info.php/products_id/74333/35612
 
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