My new old Jet Age 300

Going to check that section on adjusting ride height immediately.

Height looks good in the pictures. Most likely the shocks are garbage, and at 50+ years old the rubber bushings are likely starting to fall apart. Just start checking it over and get a plan together.
 
I would suspect the rubber bushings in the suspension (front and rear) are aged (and all that can mean). Put some weight on one of the front corners of the car and see how much it deflects under that weight (probably about an inch?) before you start going after new front torsion bars. Do the same on the rear.

Considering that Monroe Auto Equipment was Chrysler OEM shock supplier back then, that brand might now be an option. I do know that some of the factory HD replacements firmed-up our '66 Newport nicely. BUT we don't know if the current HD Monroes have the same guts/valving as what they had in 1966! Which can make the recommendtions of KYBs more appropriate for our current time.

I DO know that the old Monroe Super 500s were equivalent to the Chrysler OEM factory HD shocks. The later RadialMatics that replaced them were not the same, from my experiences.

Just some thoughts,
CBODY67
 
I would suspect the rubber bushings in the suspension (front and rear) are aged (and all that can mean). Put some weight on one of the front corners of the car and see how much it deflects under that weight (probably about an inch?) before you start going after new front torsion bars. Do the same on the rear.

Considerin

Just some thoughts,
CBODY67

Thank you, sir....for these valuable insights. All of this is great data. I push down on the car from the right rear end, and I'm able to easily push the body down 6-8 inches after 1 or two pushes.
 

My '69 had the same problem. With that suspension and too much (doesn't take much) speed and a dip in the road can result in a smashed crossmember (damhik). I bit the bullet and did the full deal firm feel suspension. Shocks don't bear weight, springs and torsion bars do. You can effectively increase spring rate (and clearance) on the front by cranking up the torsion bars (bandaid IMHO) and re arching the rear springs. Ideally you want the rear springs flat when under load, most likely yours are reverse cambered now.
 
But it also takes good HD shocks to resist compression of the springs and resultant bottoming-out. Not to forget about some "good judgement" of when you might be driving too fast for road conditions, by observation, which is what "brakes" are for.

As for the "quick lean on the fender" method I mentioned, every Chrysler product I've been around since the 1966 models has not given more than about 1.5" of downward deflection from my then-165lb body weight. Similar GM cars did more, police-spec vehicles did less.

NOW, it does not take a rock-hard spring rate to achieve this, either. I learned of a "brake-tap" action that can help, too, especially coming out of a quick dip. With some practice and good HD shocks, things can be more level than "exciting".

Remember, too, that as strong as the Chrysler UniBody might be, it will still "give" from suspension inputs. Which means that certain parts of the structure are designed to absorb/deal with these things, as other areas are not. Which means that whenever you take flex out of the suspension pivot areas with harder poly bushings, you then transfer these forces into other areas that were not really designed to deal with them. Which can lead to sheet metal cracks and similar, depending upon whether the car is a hardtop, sedan, or convertible as to just when and where these things happen, by observation. As in the allegedly typical B-body convertible cracks on the rh Dutchman panel/rh upper quarter panel joint.

All rubber suspension bushings are not created equal. Some are harder than others, by observation, especially at the GM OEM level. As the normal aftermarket replacements are usually harder than the GM OEM items were, by observation. From what I've determined, the OEM Chrysler items were harder to start with.

Now, poly bushings have their place in pivot-only locations (as in upper control arm, rear spring shackles, link-bolt sway bar ends, and other sway bar mounts which don't absorb road forces) as rubber bushings (which are hopefully of a harder durometer rating than stock) should be in road force absorption areas (lower control arm bushSome ings, leaf spring front eye bushings). Some might not agree with my hybrid approach, but after seeing the coach joint cracks develop on my '77 Camaro with the F41 and WS-7 upgraded suspension, over time, there's more flex in a unibody than many might suspect. And the GM versions of "unibody" need sub-frame connectors for their best durability, especially on T-top cars.

Just my respectful observations,
CBODY67
 
But it also takes good HD shocks to resist compression
Just my respectful observations,
CBODY67

Rebound, compression resistance of shocks is negligible. Compress a shock by hand, then try a spring. Can't even get a 1.3/8" shock in the front of a '65 ~ '73 C body without dropping the lower control arm.
 
NONE of the HD shocks for C-bodies (that I've looked at over the decades of when the 1966s were still new or "used cars") use the 1 3/8" diameter piston sizing for the front shocks. Not enough room in the tube for the larger diameter shock body. The Chrysler HDs I put under my '80 Newport (R-car) had a bulge at the bottom of the lower part of the shock, but what went up inside of the tube was the same size as a normal 1" piston shock. Of course, the rear HD shocks are 1 3/8" pistons, as normal for that type of shock, which can make un-inflated air shocks an option back there, too.

The current Monroe-Matics might use pistons between 1" and 1 3/8", but I also remember when the Monroe-Matic was an entry-level shock equivalent to Chrysler's 1" normal shock, too. Which makes me a bit hesitant to consider those shocks for anything, except as a last resort. FWIW

What made the HD shocks on the front was the valving, not the piston diameter. Back when all we knew about was piston diamters as whether the shock was standard or HD.

For the first shock replacement on the '66 Newport Town Sedan, we did Chrysler part number HD shocks. The back shocks were huge (1 3/8" diameter pistons), but the front shocks were of the normal size. As the fronts got a bit more bounce in them as they aged, the then-new Gabriel Striders had appeared, so we put a pair of them on the front. Eventually adjusting them to the 2nd notch. In that configuration, I could bound though dips in Lubbock, TX without the front end bottoming out, at the posted 30mph speed limit. With the "brake-tap" method, the car would go through the dips more level at that speed. Trying to get the car to "bounce" was not possible, as in settling things out to measure ride height and such.

Just my experiences,
CBODY67

Just some thoughts,
CBODY67
 
Beautiful car....... :thumbsup:
Lose the air shocks!!! Like Rip says.... Good quality gas shocks work best. Springs should be OK at that mileage. With new shocks installed check joust by pushing down and release at all four corners. Car should rise and settle to ride height with 1 1/2 bounces.
FYI.... springs support weight, shocks do not.
 
I push down on the car from the right rear end, and I'm able to easily push the body down 6-8 inches after 1 or two pushes.

If the shocks are functioning properly it should have stabilized from this movement within a bounce or two as bluefury stated above. That movement from intentionally loading and unloading the cars doesn't mean that your springs are shot, but if it did not stabilize within a bounce or two then the shocks are likely garbage. Oil leaks on the shock body are a dead giveaway.

FYI.... springs support weight, shocks do not.

To expand on this a little, shock absorbers are just that, they absorb the "shock" of a spring being loaded and/or unloaded at a rapid rate. To many parts of the world (who are wrong :p) they are called dampers because that is what they do, they dampen the loading and/or unloading forces.
 
I found this just laying in my driveway under the engine!..wtf..can anybody tell me what this is, where it might be from?...the rubber is completely shot to hell.

20210605_084519.jpg


20210605_084525.jpg
 
I found this just laying in my driveway under the engine!..wtf..can anybody tell me what this is, where it might be from?...the rubber is completely shot to hell.

View attachment 464408

View attachment 464413

Looks like it was some kind of bump-stop. I agree with the others, it doesn't look like a factory piece to me. Possibly an old universal replacement part.
 
"You can effectively increase spring rate (and clearance) on the front by cranking up the torsion bars (bandaid IMHO) and re arching the rear springs. "

So does adjusting the torsion bar nut affect spring rate or NOT?!?!

I was told that the torsion bar adjusting nut had NOTHING to do with spring rate and was ONLY for adjusting ride height. Had like 4 people telling me that here.

Kind of the beauty and the frustration with getting your info. from a forum. You get folks saying one thing and others saying the exact opposite. Makes it all like economics- many theories but no definitive solution. Is that what "stickies" are supposed to do- lead folks w/ questions about a particular procedure to an agreed upon answer?
I could start a new thread. Not trying to hijack but just when I think I'm starting to understand something I read a post that is totally contrary... Couldn't resist piping up.

BTW that is a beautiful car!!
 
"You can effectively increase spring rate (and clearance) on the front by cranking up the torsion bars (bandaid IMHO) and re arching the rear springs. "

So does adjusting the torsion bar nut affect spring rate or NOT?!?!

The idea I was attempting to impart was that raising the ride height would give more ground clearance, effectively increasing the spring rate. Obviously effectively increasing the spring rate was a poor choice of words. Whether new bars with a stiffer rate are installed or ride height increased, it still reduces the chance of bottoming the suspension. Which is all I meant to say.

From the story I related you know I chose the stiffer bars (1.12) as I regard raising the ride height as a less than a desirable solution, or bandaid.
 
Thanks all for the clarification. I'm a suspension kook- I don't know anything about suspension other than shocks are part of the system.
I'd like to propose a "sticky". We'll call it "Turning the adjuster nut on the torsion bars only raises the vehicle and doesn't affect ride stiffness".
 
Beautiful car....... :thumbsup:
Lose the air shocks!!! Like Rip says.... Good quality gas shocks work best. Springs should be OK at that mileage. With new shocks installed check joust by pushing down and release at all four corners. Car should rise and settle to ride height with 1 1/2 bounces.
FYI.... springs support weight, shocks do not.

This is a great forum,and all of you guys are very helpful. Thanks to all of you!
So I bounce tested the car. It's ridiculous:..I can push the entire rear end down about an inch with no force. If I rock it up and down, tbe car bounces (I'm not kidding) at least 6 inches. I feel pretty stupid, because I just assumed you know , old car..that's how they were......ooof.

I think the KYB's seem the best option .
Thanks again!
 
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