Torsion Bar Adjuster / Bump Stop

Hi, I’ve been trying to figure out why the driver side adjuster bolt is about an inch lower than the passenger side, and driver side wedge bump stop is right against the subframe? The passenger side wedge bump stop is 1/4” to the subframe.

Level floor. Original torsion bars. Adjuster bolts not stripped. 440, aluminum heads, intake manifold, water pump, battery relocated to trunk passenger side, headers.

Front end is 25” high at both front wheel openings. Rear passenger wheel openings are 25 1/2” high driver, 25” high passenger.

I had a PST front end kit installed a couple hundred miles ago, new front sway bar, tubular upper arms, and aligned, so many parts are new - but the adjuster and bump stop issue was the same before then.

See pics. I would appreciate any help and insight!

Tired bar on one side. Also ride height is checked at the control arms.

It may be possible one torsion bar was not indexed into the LCA hex like the other.

25” to top of wheel lip is sorta low. What is you front tire size? The higher the wheel diameter, it raises the wheel ball joint.

So as you increase the diameter of the tire AND keep the chassis at the same height, the gap between the LCA bumper to frame get smaller.

I would tend to agree with that ^^^.
It's a hex shape, but I don't know how the thread count would equate to the difference in clocking.
I'll assume it's got stock bars, not drag-racing or 6-cyl bars.
I've run into a deal before where the drag bars got old/weak and one side bolt was cranked to the max to keep it off the LCA bump stop.

I've been under a lot of torsion bar equipped Mopars, very few adjusting bolts have had the same number of threads showing between the bolt head and the adjustment anchor on both sides of the car. The purpose of the adjustment is to correct a minor incorrect level of the front of the car, measured at the bottom of the lower control arms at the lowest point on the control arms on a level surface. The threads on the adjusting bolt, and the height of the wheel opening are really poor points at which to check how level the lower control arms are, way too many variables involved.

Concern over a 1/4" height difference between the wheel opening on one side compared to the other side assumes the ground on which the car is sitting is perfectly level, the tape measure is perfectly straight vertical, and the both fenders are correctly positioned on the car. It is not unusual for the driver side to be adjusted slightly higher then the passenger side at astatic level to compensate for not having a driver sitting in the seat, the theory is, once the driver is in the seat, the car will sit level. Mopars of the performance era were designed with a panel tolerance of + or - a 1/4". Your measured difference is well within the factory tolerance.

Personally, I'd go with the ground wasn't level, or the tape measure wasn't straight, and no one is going to crawl under your car and count the number of threads on the torsion bar adjusting bolt sticking below your control arms. Then I'd move on to more important things. Gene

hi
do you have a pair of bar one right and one left , they are different !

I am with autoxcuda was not indexed right

First, thanks everyone for the help.

I’ve got the front intentionally at 25”, for a slight grade down from the rear. The well lips just hide the tops of the tires. F is 225/50/17 R is 255/50/17.

I’m thinking incorrect indexing is the most likely. The torsion bars were removed and reinstalled about 20 years ago at a shop, but frankly I don’t remember if that’s when I first noticed the issue or not. The only worn parts left to be considered for replacement are the torsion bars themselves. They are the 778 and 779 for the originally 383 car (440 now). 0.90 diameter. Correct sides.

Don’t like the bump stop being sandwiched. Limits the travel on one side.

May as well replace the bars. The current bars are 50 years old and prob not like being twisted to correct install. Likely some metal fatigue. I like the way the car rides currently, but wouldn’t mind a little stiffer. No potholes or rough roads where I cruise. Planning for the PST version - 20 degree clocking: 1.03" Torsion Bar Deluxe Kit - Polygraphite - B & E Body. Other than being a little lighter in the wallet, I don’t think I’ll be any worse off with new bars, that’s for sure.

Could be several different things. Put the car up on the lift and pull the bars out and check it out. You're more likely to find the problem by looking at the parts. I doubt the bars are indexed wrong, probably just a weak bar.

Gang, I've played around with a lot of different bars, but I don't think you could be off on the hex. That is 60 degrees and would probably show up on the adjust bolt at like two inches. I would like to hear from somebody to see if it has actually happened because in my experience you would never have enough adjustment to even bring the lower arm off the rubber stop.

This ^

Can't be indexed wrong.

When you check the ride height it isn't just "measure to the floor". It's the differential measurement between basically the LCA bushing and the lower ball joint. There is a photo in the FSM that shows the locations.

Start at the basics.

Without anyone in the car at first. (Some people align a car with driver weight in the seat and that is fine but not for diagnostics.)

Put it on a flat level floor. Measure from the ball joint on each side to the ground and from the bottom edge of the LCA hex socket to the floor. The difference is the adjustment height. Should be about 1-1/8" if stock.

If it is not a significant difference between sides, and you have bumper distance/space issue, then you have issues with the bumpers not matching, or a bent arm or chasis etc.

If you even out the height, and the bumper issue goes away but the bolt is excessively different, You have torsion bar issues. 2 bars of the same side in the car, old & saggy bars, bars on the wrong side, indexed incorrectly, etc.

Some people will say that you can't index them wrong etc,, and they are correct in a perfect world, but I have seen many things that a mechanic should not be able to do, be done by bad mechanics. Never underestimate the ability of a bad mechanic to achieve unachievable heights or depths in stupidity. I know this because when I was younger and learning I did a lot of stupid stuff you shouldn't be able to do to a car. I did them quite well too.

HEY ! i'm old and STILL do stupid stuff !

Yeah I agree. I'd have to see a video of someone installing a torsion bar off one hex before I believed it. I don't think there is enough travel in the lower control arm to be off one flat. If you switch bars side for side then that is half a hex and even that is tough to do. I tried to install bars on the wrong side once but could not do it due to lack of travel. I've heard of people having the bars on the wrong side so perhaps it can be done but it messes up the adjustment for sure. One of the torsion bar suppliers hired me a few years back to help them sort out a hex offset issue. As the torsion bars get bigger, the offset has to be carefully calculated or else the adjuster won't have the correct travel. The position of the hex needs to be held within a few degrees for the adjuster to work correctly so there is no way a big bar can be off by a flat or even a half flat.

Yea, with big bars you don’t have that error margin.

I agree it’s pretty tough to mess up with a stock bar. And the adjuster would be way in or way out and the ride height would be real low or high. I’ve see a car with the adjuster bolt completely out and the adjuster arm just sitting on the pad/nut.

Either way, a hex issue it not going to fix his static bump stop to frame clearance. That is purely a function of ride height and tire height. So the OP needs to change one of those OR just put in a shorter bump stop.

Most people set the ride height to the look they want. Typically that look is the body relative to the ground and/or tire. And then match that height side to side.


Here’s a short bump stop you can buy and move on with your life.



https://www.amazon.com/Energy-Suspe...&hvtargid=pla-569060105739&psc=1

Check the sleeve in the k-frame where the lower arm shaft goes through. Maybe have issues with the weld or it cracked, both allowing it to spin.

This discussion reminds me that back in 1957 when, I guess, Chrysler's torsion bar front suspension was first introduced, there was a dealer's Plymouth running around town with only one front wheel, an obvious publicity and promotion stunt to get gawkers and generate new car sales. I saw the car with my own eyes making a turn at an intersection.

Back then, the fall introduction of new car models was a very, very big deal.

Somebody needs to copy this feat and post photos of the car turning a corner.

I had a similar problem after replacing my rear shocks and wanted to bring the front end up, which I did, and everything seemed ok. After a few trips something didn't seem right which I attributed to a slow leak on the drivers side tire, although a little inconvenient I fill it to the proper inflation and go on my way, I'm getting new tires soon but am not really ready yet. Any how, even after inflating the tire the driver side seem lower and upon investigating the situation it was close to 3/4" difference after measuring on a reasonably level surface. I got setup and started to crank up the adjustment bolt and slowly started to get it to match the other side and jostled it like suggested and it seemed to settle about a 1/4" or so I cranked it up a few more turn when..."oh no" the wrench gave way and the adjustment bolt came out. A couple years back I had rebuilt the front end when I converted to front disc brakes. I replaced the bushings and pivots, but not the adjusters as they seemed to be ok, needless to say this one was not and stripped. I don't know if you got yours straighted out, but it could be something to consider. I looked into getting some new one and they are pretty pricey, being a good Mopar guy I ha some extra lower control arm laying around and was able to replace it and get back on the road

Had this happen once. Went to do a slight adjustment with full weight on the suspension and the threads let go. That was a scary moment when the wrench went flying and the vehicle dropped. I had just put the entire suspension together and all looked ok when reassembling.

My guess is for this OP the one bar is going soft or maybe it was the wrong bar reinstalled? If lucky the partial part number could be visible from the cross brace opening, if it isn't flipped around.

It is not unusual for the adjusters to be different settings. There are few scenarios.
Torsion bars are spring steel, and for one to be precisely the same strength as the other is unlikely, and they could have fatigue too.
The rear springs also play into this. If you have a rear spring with a higher arch to it, that will force the opposite front corner down. You then would need to crank that front adjuster up, to compensate.
And, if the car has ever been put in the ditch, or crashed with one front rail kicked up, the car is no longer level to the datum plane. Meaning it has a twist. There are way more cars with that issue than you would think. A wide gap at the lower fender to rocker on one side is a quick indication of that. These old cars have lots of adjustment and slotted holes for a reason. The front fenders can be moved around a lot, to compensate for a twisted front structure. You can adjust the fenders around to hide a significant wist in the front structure.
If the front of the body is perfectly level to the level floor, and the rear of the body is not, your car is twisted. The adjuster is cranked way up trying to compensate.
Try this:
Ideally you would do this on a frame rack which provides a perfect level surface, but if you have a very good level concrete floor, that will suffice.
Put the car up on 4 jack stands at the ends of the rockers [torque boxes], and level it so the rockers measure identical side to side, to the level floor. This will place the center of the car perfectly level with the floor [datum plane]. It is very uncommon for the center section of a car to twist, so this section should be virtually perfect as far as measurement from the rocker to the floor.
Now, measure the ends of the frame rails to the floor. The rears are generally quite level, unless the car has had a significant rear end collision. a little varience is not unusual even from new.
Measure the front rails close the rad support, down to the floor. If one front rail is noticeably different measurement, then your front structure is twisted. It is most common for the right rail to measure higher from the floor, due to cars hitting the ditch. Frame rails will kick upward from an impact, causing a wide fender to rocker gap on that side, making the car sit low on that corner, so that torsion bar adjuster will need to be cranked in to raise that corner.
While measuring, also measure the 4 wheel openings to the floor. If the car is truly square, every measurement will be identical from side to side. If the rockers are square to the floor, and the wheel openings are not, then something is off. Usually it's one front rail kicked up.

Yes it was a little scary when it let go. I had ratchet and socket on a short piece of pipe so I didn't have to get so far under the car.