Question about Torsion Bars

[saforwardlook]

When I was doing my suspension the general consensus on the board was either the torsion bar is either good or broken, confirmed by PST . They recommended, if they weren't broken or if I didn't want a stiffer ride, do not change them.

I think you have something together incorrectly or something is broken and you don't know it.

I have seen this uneveness of torsion bar adjustment numerous times and believe it is primarily due to the heat treating process in making the torsion bars in the first place that cause the bars to weaken at different rates over time. Back in 1957 when torsion bars were first introduced on Chrysler products, there were many issues of some bars suddenly breaking without warning while most did not and it was ascribed to variations in the manufacturing process that had to be tightened up. I believe the PST recommendation not to change them is acceptable if everything else is normal given the nature of the issue. Generally ride and handling are not affected significantly by this reality in my experience and the ability to align the vehicle is not either (but worn bushings or other similar issues will affect alignment capability).

I also believe a consensus is general by definition...............

 

[mr. fix it]

Im with you on this call. Ive watched a ton of videos on getting those bars out and then the beast of dealing with 50 year old LCA bushings... I wish I knew a shop that would actually work on this thing when I dont want to. LOL

Mine were covered front to back in grease & oil. I must have gotten lucky that the PO's didn't remove any of it over the years. The torsion bars slid right out when I took the tension off the screws.

 

[Davea Lux]

Someone has tried to correct a ride height issue by messing with the torsion bar adjustment, reset the adjusting screws until they are both the same, do this with the car jacked up. Your LCAs do not show any obvious signs of being bent enough to cause an alignment issue. With car up and supported in a level position with the front tires off the ground. Check the front cross member for obvious rust damage or large dings. If that is clean, measure from the base of the ball joint to the floor on both sides, measurements should be the same. Next measure from the torsion bar socket to the floor, those measurements should also be the same. I suspect that you are going to find a significant difference in the measurements from the left and right. Is the steering shaft going into the steering gear straight or is it distended up or down or to the left or right? This is usually a sure sign that the stub is bent. I would suggest as others have noted, that you pull both LCAs and replace those bushings and strut rod bushings and then repeat the measurement process. If you are getting any clanking or clunking from the front end, especially on turns, that is usually an indication of failed bushings, as is pulling to the left or right.

Dave

 

[Davea Lux]

While you have the torsion bars out, check the markings on the ends. One will have an even number and one will have an odd number, usually the numbers will be something like 618R, 619L. They are matched pairs. Mopar used the last three digits of the part number. The other end of the bar will usually have a foundry number and date.

Dave

 

[HWYCRZR]

Mine from right to left are a little different but only by about 1/4” To get equal height. And my alignment and ride heights are perfect.
Remember there are 6 hexes on the shaft there could be a possibility that one shaft is 1/6 turn off from the other.
The rotation arm length of the adjustment cam looks to be about 4” from the center of the torsion bar. Using work bench math 1/6 rotation moves the cam about 3” the bolts are about 4” long, and if the car was jacked up for install it could be possible It should be highly noticeable if you back the adjusting bolts all the way out to until the cams are free floating to make sure you are starting from the same adjustment point on both.

 

[CBODY67]

(This deal is still going?)

Head over to www.mymopar.com and look for the Chrysler MasterTech section on front end alignment. It should have a good explanation of what the various things are.

Caster and camber are easy to determine, just as toe-in is. It's all geometry, not "black science". NO electronics are needed, but they can measure things a bit finer, in some cases.

Then, head down to the home improvement store and get a magnetic base angle meter that will operate in the vertical plane of things. Plus a good tape measure and probably a grease pencil. Then find a level floor to do the measurements on.

End result, you'll have some tools to which do the measurements of the angles and such necessary to align a vehicle. Seems like Summit also sells a kit to do this with?

Enjoy!
CBODY67

 

[cbarge]

Not sure if anybody mentioned this..but ride hight MUST BE SET BEFORE ALIGNMENT.
In my world,not uncommon to see one bolt in/out more than the other.
With the car on a level surface--or on the alignment hoist. measure from the bottom of the front tire to the wheel lip. Typically should be 27 inches give or take an 8th of an inch. Always jounce the car after each adjustment.
Both sides of the car should be equal regardless where the bolt stands.
Not knowing the car's history,it may have broken a bar and was replaced with an incorrect thickness bar..hence being cranked up.
But that is a wild guess.
Also mentioned before check your lower control arm bushings. If they are toast that can affect your alignment.
Hope this helps.

 

[CBODY67]

As to the issues mentioned. Torsion bar adjustment has nothing to do with the non-return of the steering to straight-ahead after a turn. That's in the gearbox, only, unless something in the steering linkage is binding.

As for pulling or leading to one side or the other, there are virtually NO level roads in this country. They all will have a slight lateral angle to them for water drainage, by observation. Back when many roads were cambered (rounded), it was common for an old-line alignment person to set the caster to keep the car climbing up onto the road (without having to turn the steering wheel to make this happen), but when the vehicle got to a flatter road, it still wanted to climb up on the road (although it was flat), which meant it pulled to the left on the more-flat road. Which, in more modern times, generated the "cross-caster" and "cross-camber" tolerances, with one side being more than the other so it would "drive straight" on those cambered roads.

By observation, the camber correction upper control arm bushings (or similar) are designed to compensate for a sagged front crossmember (which, as it tuned out, almost all GM cars can tend to have, especially with the big-block V-8s in them), over time. Which can also mean they could be staggered, front to back, to increase or decrease caster from OEM bushings.

One observation from what myself and others I've known about, over the prior decades, later determined, is that the desire to "make it better" can also cause more problems than it was worth. Also proving that "factory stock" was pretty good as it was before we started to "jack with it". Not that some tweaks might help things along, but getting things out of the OEM realm of things can be troublesome.

Just some thoughts,
CBODY67

 

[cbarge]

As for pulling or leading to one side or the other, there are virtually NO level roads in this country.

Agreed. New roads have a crown to them for water to roll off the asphalt..
Then there are the not so new roads...different topic for another day.

 

[mr. fix it]

Agreed. New roads have a crown to them for water to roll off the asphalt..
Then there are the not so new roads...different topic for another day.

That's the beauty of Radial tires on our old boats.

Get onto a bumpy or wavy road surface & it's going to grab every single one of the imperfections, hug it like it's your first new born child & try to take you places you don't want to go especially if you are on the opposite side of a crowned road attempting to pass a slower vehicle!

 

[Jeff Skibenes]

There is also a left and right torsion bar. If they were ever removed for any reason, they might have been switched, that might affect how the bar adjusts.

As stated above, take the bolts out completely and make sure they are the same length. A lot can happen in nearly 50 years, never say never.

IMHOP, you should pull the LCA’s and redo the bushings anyway, it will give you the chance to inspect the bars and all the associated parts.

Pardon my stupidity, but what are LCA's?

 

[badvs3vil]

Pardon my stupidity, but what are LCA's?

Lower Control Arms.

 

[Jeff Skibenes]

Lower Control Arms.

Ah gotcha