PST 1" front swaybar, on 65 Chrysler 300L

[fury fan]

So I was working on the bottom of the priority list and decided to revisit the 1” PST swaybar on my 300L. Did some googling to see if there were any new players on the C-body swaybar arena. Didn’t find any prospects, all references were to bars listed also for A & B-body (they aren’t gonna work), or bars that were not available. I don’t know exactly when I bought this bar, back in 2016 I tried to sell it because I couldn’t get it to fit properly, but had no takers. It had been on the car for a few years at least.

Here’s a pic from a Mopar Muscle article on a 69 Newport (from 2012).
https://www.motortrend.com/how-to/mopp-1204-c-body-sway-bars-roll-control

This Mopar Muscle pic doesn’t show that the bars are different. Read on...

Apparently I sold my original bar at a swapmeet, but I recently discovered this ⅞” bar in the basement (I cannot recall where/how I got it).
If it was a 15/16” bar I would put it on and been done with it, but at only ⅞” dia the PST bar should be a significant improvement, so this was worth another revisit.

So here’s a pic I took, with them laying on top of each other -- the PST bar is clearly shorter and wider. (!!!)
This explains why I had such a struggle figuring out how to fit it.

Here’s a pic of the Mopar Muscle installation. As we can see, their installation differs from factory, the end of the bar attaches above the strut rods.
And it looks like it’s not tightened properly either (read on). I say this because the bolts appear to be parallel (but the pic isn't the best)

And here’s a pic of the bar as installed by @Zymurgy, routed below the strut rod as the factory did. I trust Zymurgy’s efforts far more than a magazine!
Sway Bar Endlink Brackets

No blame to anybody, because my memory of the installation instructions is that they sucked bigtime (hand sketches and typewritten). Back in the day (2016) I tried a bunch of variations on mounting this bar: mounting it above/below the strut rod, and 2 orientations of the saddle brackets there + reusing the original strutrod brackets. I tried all 6 setups and none were correct, all of them ended up with the frame links angling toward the rear of the car. It must move rearward from the factory location due to being shorter/wider.

I had to bend the saddle brackets to get it to tighten up properly.
Zymurgy’s pic looks like the 2 bolts aren’t pointing the same direction, so I’d bet he had to bend brackets same as me.

In the above pic, the saddle bushing is oriented in the wrong plane, but is to show the bend.


My concern with this is: with the bar being wider, the mounting to the strut rod is cantilevered, and with the LCAs moving in an arc, the bolt thru the swaybar is going to see a lot of bending stress. OR - the saddle-bushing is going to rotate somewhat on the strutrod and not transfer the motion into the swaybar. The original bracket clasped both sides of the swaybar’s end, putting the bolt in double-shear (better enginering), and the bar terminated vertically from the strutrod, forcing 100% of the motion to the swaybar.

 

[fury fan]

Interestingly enough, this swaybar I had laying around hits the endpoints better than the PST. It’s from an ‘88 T-Bird turbocoupe, and is a tick over 1-¼” dia. How awesome might this be???
But to cut to the conclusion: due to the big droop, it would need saddle brackets to the framerail to get ground clearance (not simple but do-able), and that puts the ends close to the strut rods as original. I could make some simple brackets for that, but that makes the mounting *really* stiff, and it would have no endlinks. I’ve never seen a swaybar mounted ‘tight’ at all 4 points, they always have endlinks somewhere. My concern is that such a stiff bar, mounted so tightly, might end up tweaking my strut rods, or making a lot of bushing noise, and surely overpower my mushy 215/75-14 tires.

Would need to fab something here, perhaps a ½” plate with a countersunk allenhead bolt up thru the factory frame bracket, and drilled/tapped for bolts to hold the saddle bracket into it. Would have a bushing on top of the factory bracket as original, and optionally one below, sandwiched between the thick plate, to add more compliance to the setup if needed.

I considered mounting the saddle brackets more outboard, directly to the frame, but the curve of the bar would put the bolts really close to the inner edge of the framerail, and would put bushings on the worn/abraded section of bar. I’m usually pretty decent at fab work, but this one looks like high potential to make an error and put some bastardized holes in my frame. Veto for that mounting method.

The end attachments would require a top/bottom bushings at the swaybar, then an angle bracket to tie to the OEM strutrod bracket, which would require some mods and flipped top/bottom.

But I like the idea for the future, if funding doesn’t permit a FirmFeel bar, which I have on another car and it fits awesomely.

 

[fury fan]

End result - PST bar, with OEM brackets and not-ideal bushing mush.

I put the best set of bushings I had on the strut rods, they are parts-store versions that do not have the extra tab of material to fil the gap between swaybar and strut rod. The issue gets worse when you have a bar that isn’t formed identical to original. I had to really tighten the 2 bolts to draw all of this together, and the bushing has to mash to make it happen. I have recently gotten a new set of these bushings that are significantly harder, so when I get a chance to revisit we’ll see if they hold shape better.

Due to the swaybar not being long enough, something additional has to compromise to make this work - the frame links are angled rearward. The photo does not exaggerate. Bushings at the frame bracket were given a libel coat of silicone grease, which I bought recently for re-doing my shackle bushings with polyurethane. Strut-rod bushings were not greased as I intend to revisit.

 

[fury fan]

Results:
Before all this, I had some rubber squeaking in the front end in turns (I always suspected this bar). But no noise now.
I don’t know if the silicone grease cured it, or if it was better installation with OEM brackets at the strut rod (although those bushings are dry because I intend to swap them).

Driving it is an improvement from before, and significantly better than stock (from my memory, anyway). It has very little lean in turns in the neighborhood. If I had bought a car modified this way (and didn’t know all these details) I’d probably be obliviously happy with it. It’s good enough for now, one day when I get better tires (or spare time) I’ll see if I can improve this.

I don’t know if PST is aware of this bar’s issues, or if the dimensions of it are improved. Maybe I have an early-revision of bar. I dunno.
But I would encourage any new buyers of this bar to compare it closely to their OEM bar and be watchful of how well it fits.

 

[Big_John]

The only issue with putting an oversize front sway bar on the car is you increase understeer. You won't notice until you really push the car, but it will want to go straight rather than turn.

Front engine RWD cars understeer enough as is.

The good solution would be to add a rear bar. A rear bar alone will increase oversteer, which is never desirable, unless you are driving a drift car. Put the bigger front bar together with a good rear bar and that would be the best.

 

[CBODY67]

In one respect, it always kind of looked like the front sway bars on the Slab C-bodies were an afterthought of sorts. Something which later B-bodies did a better job with. When the first torsion bar suspensions were designed in the middle 1950s, front sway bars were not that important of a suspension tuning device. Even as late as 1967 or 1968, a front sway bar was an option on 318 Furys, but standard with B/RB Furys.

With the architecture of the front suspension LCA, about the only place they could affect roll stiffness and not straight-line ride quality would be the way they did it, attaching the sway bar to the LCA struts. By observation, the sway bar end bushings got wallered out from up and down motion, which might make the effectiveness of the sway bar a bit diminished. But a more-solid polyurethane bushing might put stresses on the strut bar it was not really designed to sustain? Unless the strut rod attachment had some way of pivoting on the strut rod attachment.

Personally, I always thought that adding a rear bar would be a better situation. GM was first to do that with the GTOs during the DeLorean years, then other divisions followed on the intermediate platforms, with Chevy then doing their F-41 suspension on the full-size cars (which included a rear sway bar). Chrysler, reportedly, claimed that with the stiffer rear leaf springs on their HP models, adding a rear bar would put too much roll stiffness in the rear, which would allegedly make the cars slide off the road on a washboard surface. BUT then came their Radial Roadability option package on the '74 Road Runners, which was HD shocks and springs (standard on the RR) W23 15x6 wheels, Goodyear radials, AND a rear sway bar. With the '75 Cordobas have a rear bar as a part of the situation. Guess they found some way to make it work, to compete against the GM cars which also had rear sway bars?

In the middle 1960s or so, Helwig sold rear sway bars before they were popular. Even one for C-body cars. Never saw one, just an ad in a car magazine.

As to your "mushy" tires, try running 32psi frt and 30psi rr pressure. See if that doesn't firm things up, even on the stock 14x5.5 wheels.

One other thing I recently became aware of . . . "Caltrac" traction bars for leaf springs. Saw some on a Ben II Camaro rear springs. Look like a heavier-duty version of the old Traction Master traction bars, with adjustments and much stouter attachments to the springs and such. Something like that, with a rear sway bar attached between them, might be an easy "no drill" way of attaching a rear sway bar? While also limiting spring deflection under torque and in turns?

Just some thoughts and observations,
CBODY67

 

[Luke Pokrajac]

I bought and installed the PST sway bar on my 68 sport fury convertible. Never liked the way it fit, and it squeaked/clunked when turning into driveway curb approaches, etc. Took it off and put the OEM one back on with all new bushings. Car did seem to handle better with the PST sway bar installed.

 

[fury fan]

The only issue with putting an oversize front sway bar on the car is you increase understeer. You won't notice until you really push the car, but it will want to go straight rather than turn.

Front engine RWD cars understeer enough as is.

The good solution would be to add a rear bar. A rear bar alone will increase oversteer, which is never desirable, unless you are driving a drift car. Put the bigger front bar together with a good rear bar and that would be the best.

I can't recall the last time this car saw more than 45mph in a straight line, so flatter handling trumps concern for oversteer.
Eventually I'd like to do a rear bar. I have a buddy with a small pile of mid-70s M- and R-body rear bars, I'd like to see if one of them can be made to fit.

In one respect, it always kind of looked like the front sway bars on the Slab C-bodies were an afterthought of sorts. Something which later B-bodies did a better job with. When the first torsion bar suspensions were designed in the middle 1950s, front sway bars were not that important of a suspension tuning device. Even as late as 1967 or 1968, a front sway bar was an option on 318 Furys, but standard with B/RB Furys.

As to your "mushy" tires, try running 32psi frt and 30psi rr pressure. See if that doesn't firm things up, even on the stock 14x5.5 wheels.

One other thing I recently became aware of . . . "Caltrac" traction bars for leaf springs. Saw some on a Ben II Camaro rear springs. Look like a heavier-duty version of the old Traction Master traction bars, with adjustments and much stouter attachments to the springs and such. Something like that, with a rear sway bar attached between them, might be an easy "no drill" way of attaching a rear sway bar? While also limiting spring deflection under torque and in turns?

Just some thoughts and observations,
CBODY67

I agree the swaybar mount to the strut rod wasn't well-planned.
My avatar car was a 318/non-swaybar car. Ironically (or intentionally), it had the thickest .99" T-bars on it.
That has been rectified into 1.12" T-bars and a 1-1/8 Firmfeel swaybar.

I'm generally topping the tires off at 35psi. Would be interesting to drop to 28-29 and then boost to 35 to see the difference.

I bought and installed the PST sway bar on my 68 sport fury convertible. Never liked the way it fit, and it squeaked/clunked when turning into driveway curb approaches, etc. Took it off and put the OEM one back on with all new bushings. Car did seem to handle better with the PST sway bar installed.

Glad to hear you had the same findings/result. Well, not glad you had trouble, just glad it wasn't something I did wrong.

 

[CBODY67]

Had a Mopar friend who used a '76 Cordoba rear bar on his '65 Polara. Said it needed just a touch with a torch to get it to line up with the rear spring pads and such. Said it helped a good bit. That was back in the 1980s.

CBODY67

 

[Darby]

I went with PST for the sway-bars (1" front - 3/4" rear) for my '65 SF. I installed the same front bar as others here, because that's the only one available and of course, I had the same fitment problems. I went as far as to change the small pieces of pipe to see if different lengths would make it better. In the end I installed the ones that came in the kit. Now that I have sets of different lengths, it'll be no big deal to change this later if needed. It takes a while to find the best way to mount it so it doesn't contact the strut-rods, but I think it's good now. I can only drive my car around in a big parking lot because there's no glass, interior, bumpers,......... you know, still in process, but it has been running for about a week now!!!!
I also added the rear bar and if you go that route, it doesn't fit either. If you mount it and then try to install the fuel tank or the exhaust (I have 2.5" TTI), you'll find the bar will not fit as directed and has to be unbolted from the frame. To make mine fit, had to make another base plate like the one they provided and weld a piece of pipe between them to move the bar about 1.5 inches away from the frame. I'm not near my car now, or I'd add a picture. If there's any interest, I'll post one later. I went with Firm Feel for my springs (1.5" drop), firmer torsion bars (1.12" 44"long - HD/street app), and tubular upper control arms; I wanted to have more positive caster than we can get from stock control arms. This thing should handle and ride like a much newer car now. Matt at Firm Feel said the "floating" down the road will be gone with this bar/spring combo.

 

[fury fan]

I have the 1.12" FF T-bars and yes, my car rides much like a modern one (aside from the steering).
I tried 2 rear bars (Addco, I believe) many years ago (with about a 10-year gap in between) and couldn't get either one to fit, not even close.

I used one of them for hanging things to spray paint.