Torsion bars and lower control arm set-up

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SB69GTS

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Hey guys, got the 1.03 torsion bars in and was wondering if someone can chime in on the adjustments. The lower control arm adjusting bolt was loosen right off .... this is a complete resto so when i rebuilt the lower control arms ...I did not tighten the torsion bar socket in them. Now I turned the bolt till it snugged up to the indent and did 6 complete turns .... before I lower the car down to the ground ..I started thinking ....should I have tightened the torsion bar socket nut first or is it ok now with the adjusting bolt for the torsion bars in 6 turns and lower the car to the ground and tighten the torsion bar socket nut. Also does any know the torque setting for the nut on the torsion bar socket in the control arm. Hope this makes sense. Its on a 69 dart with a 408 stroker, auto trans. Stock lower control arms
 
Are you talking about the height adjusters or the LCA pivot nuts?

Most guys advocate final tightening of the LCA pivots when the car is on the ground, has been "jounced" and sitting at ride height

The adjusters about all you can do is "start somewhere" and see what you have for height. Most guys seem to want to adjust them when jacked up/ weight relieved
 
Just don't adjust them up or down unless you have the car supported.
 
The car should be on the ground ,the ride-height squared up and set, and then rolled a distance about equal to the front tire circumference to relax the suspension and tires. Every time you reset the ride-height, the car should be re-rolled.
Then you can secure the LCA pivot pins to the K-member, with those big nuts.
 
Like Del and AJ said, leave the lower control arm pivot but loose until you have the ride height set, once you have the ride height where you think you want it, roll the car back and forth a few feet, it'll probably settle some, requiring you to readjust a little. Once you have rolled the car back and forth and the ride height is where you want it, torque the pivot nuts to 145 ft lb. If you torque the but before setting ride height, the LCA bushings can wear out prematurely
 
You only have to worry about doing the final torque to spec on the LCA pivot nuts at ride height if you've got the OE style rubber LCA bushings. If you have poly or delrin LCA bushings it doesn't matter at all, you can torque the LCA pivot nuts to spec at any location or setting. And note, if you're using the OE rubber LCA bushings you still want the LCA pivot nuts snug before you put the car on the ground, just don't fully torque them to spec. You don't want the LCA's flopping around when you set the ride height, so snug them up but don't tighten them. If that makes sense.

Also, another interesting note, the OE rubber bushings are not bonded to the inner or outer shells. I'd always heard that the rubber was somehow bonded to the shells and that's what was damaged if you didn't torque the pivot nuts at ride height, but in fact the bushings and shells are just held in place by compression and friction. I took apart the bushings in the QA1 tubular arms I bought to upgrade them to Delrin before I installed them. Everything came apart smoothly in the press, you can see how the size of the bushing causes a compressive force that holds everything in place.

QA1 tubular LCA as supplied with OE style rubber bushings. Not sure why fancy tubular LCA's come with rubber bushings, but they do. And yes, I did some TIG welding on brand new tubular LCA's to add gussets.
IMG_3921.JPG


LCA pin pressed out, bushing still intact
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Inner shell pressed out, you can see how the bushing has already deformed and shrunk to be smaller when the inner shell isn't forced into it
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Fully disassembled. Notice the shape of the bushing with the outer diameter now larger than the outer shell and inner diameter smaller than the inner shell, and perfectly clean shells.
IMG_3925.JPG


Anyway, doesn't matter, when the OE rubber bushings are fully assembled you can tear the bushing if you don't torque it at ride height because the compression and surface friction forces will keep the shells from turning and the rubber of the bushing can tear because nothing will move on the surfaces. So the procedure is the same. It's just not because anything was bonded together first.
 
This is GREAT things to know . Next question : What and how to set ride height ? I tried to set mine according to the MOTORS Repair Book and one side was 1" higher than the other . ????
 
This is GREAT things to know . Next question : What and how to set ride height ? I tried to set mine according to the MOTORS Repair Book and one side was 1" higher than the other . ????
Ride height is all personal preference, imo. I finally you want it set to exactly factory height, I think 72blu has a picture showing how that's done. I prefer my cars lower than ride height so I just set it to where I like the look and go with it. Mine is 25.5" from the ground to the highest part of the wheel well lip
 
Ride height is all personal preference, imo. I finally you want it set to exactly factory height, I think 72blu has a picture showing how that's done. I prefer my cars lower than ride height so I just set it to where I like the look and go with it. Mine is 25.5" from the ground to the highest part of the wheel well lip
I try to center them between the jounce and rebound bumpers. If you lower it too close to the bumper, it can put a bind on the control arm travel, it will ride like crap and you just might break something. Years ago, I bought a repo Dustpan. The PO was a huge fan of the snow plow look. It was riding on the lower control arm bumpers, and had cracked the upper control arm frame ears, among other damage.
 
Thanks guys ...great info and pics. Now time to move to installing the glass and finishing the interior. 4 years of labour and might have her on the road shortly.

20161208_113018.jpg
 
Ride height is all personal preference, imo. I finally you want it set to exactly factory height, I think 72blu has a picture showing how that's done. I prefer my cars lower than ride height so I just set it to where I like the look and go with it. Mine is 25.5" from the ground to the highest part of the wheel well lip

Why yes, yes I do...

factoryalignspecs.jpg


It's straight out of the service manual. I combined a couple of pages so all the relevant info was in the same shot. That said, I would NEVER run the factory alignment specs with radial tires, they're for bias ply's. And yes, the ride height specs are completely irrelevant if you have upgraded your torsion bars. The wheel rate on a set of 1.03" torsion bars is roughly double the factory torsion bars even if you had V8 bars to begin with. So, you'll have about half as much suspension travel as the stock bars, which means you don't need to use the factory ride height specs to stay off the bumpstops.

Alignment numbers for radial tires should come from this chart. The caster specs are on the conservative side, you can run more positive camber if you can get it.
alignment-specifications-jpg-221767-jpg.jpg
 
Why yes, yes I do...

View attachment 1715054878

It's straight out of the service manual. I combined a couple of pages so all the relevant info was in the same shot. That said, I would NEVER run the factory alignment specs with radial tires, they're for bias ply's. And yes, the ride height specs are completely irrelevant if you have upgraded your torsion bars. The wheel rate on a set of 1.03" torsion bars is roughly double the factory torsion bars even if you had V8 bars to begin with. So, you'll have about half as much suspension travel as the stock bars, which means you don't need to use the factory ride height specs to stay off the bumpstops.

Alignment numbers for radial tires should come from this chart. The caster specs are on the conservative side, you can run more positive camber if you can get it.
View attachment 1715054884
the "factory" specs are amusing in light of the fact, when I picked up my new AAR in 1970, it was nearly riding on the LCA bumper. That's how they got the "NASCAR look" they touted in their marketing program, back in the day.
 
the "factory" specs are amusing in light of the fact, when I picked up my new AAR in 1970, it was nearly riding on the LCA bumper. That's how they got the "NASCAR look" they touted in their marketing program, back in the day.

That wasn't actually the factory spec though if you look at the measurements. That might have been something they did at the dealer to sell the car, or someone screwed up.

Oddly enough, the AAR and T/A cars that were actually raced in the TransAm series were higher than the factory spec to clear the tires they were running for the competition.
 
That wasn't actually the factory spec though if you look at the measurements. That might have been something they did at the dealer to sell the car, or someone screwed up.

Oddly enough, the AAR and T/A cars that were actually raced in the TransAm series were higher than the factory spec to clear the tires they were running for the competition.
nope, that was the way they came. They also had special rear springs, which contributed to the rake. I'm pretty sure the rear springs was for clearance on the side exit exhaust, which came in pieces in the trunk, because it wasn't legal in some states
And no, the dealer never touched my car.
 
Ride height is all personal preference, imo. I finally you want it set to exactly factory height, I think 72blu has a picture showing how that's done. I prefer my cars lower than ride height so I just set it to where I like the look and go with it. Mine is 25.5" from the ground to the highest part of the wheel well lip

Thanks. Went from 27” to 25.5”. 2 full turns. (Control arm bolt lossened than torqued at ride height)

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0F8B3312-0C86-46E8-8BFB-5F3689B51376.jpeg
 
it looks good to me, as long as tires clear sheet metal, you're not riding on the lower control arm bumper, and you're happy with it.
 
Looks great! :thumbsup:

Don’t forget that you’ll need to get a new alignment now.

At that height you’ll also need low profile
bump stops and larger than factory torsion bars, if you don’t have those already.

Well crap its always something. Looks like I'll be calling pst for some 1.03's in the near future. Should have plenty of time being as we're suppose to get 8" of snow sunday.
 
Well crap its always something. Looks like I'll be calling pst for some 1.03's in the near future. Should have plenty of time being as we're suppose to get 8" of snow sunday.
Bergman auto craft has 1.08” bars for $275 a set
 
47EBBC35-D071-47B8-94B2-9100FA9666C8.jpeg

The left rear adjuster is jacked up. Cam will only turn so far. This is as good as he could get it for now.
 
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