Any benefit to poly LCA bushing?

70 Challenger
Looking at replacing the LCA bushings, I see they now have new greaseable shafts for the poly bushing set-up.
Is there any benefit over the stock rubber set-up?
Do the pivot shafts really need to be greased enough to require a fitting?

https://www.supershops.com/products/chassis_suspension/control_arms/parts/120-10005

The firmer the bushing is, the less deflection it'll have, in general terms.
Side effect is less absorption of vibration and noise.

Closest I can offer a comparison is 2 different vintage TransAm race cars we restored & ran some years back, though the cars themselves were different:
1. Ex-Penske/Roy Woods Javelin, no rubber in suspension/steering
2. Privateer 69/70 (raced as both), had some rubber in suspension/steering

The Javelin was more consistent & confidence-inspiring when pitched around on-track vs the Mustang.
The Javelin also had more power, so it would seem logical that if the two had equal power, the difference would be even larger.
Both cars were optimized as far as settings, though the Javelin was originally a further-developed car.
That's with both cars having their necks wrung; at less intense driving, that edge didn't seem very noticeable.
My buddy, who'd done well in SCCA A/Sedan in SoCal, and in other stuff like pavement Sprint Cars, called the Mustang a pig in comparison to the Javelin.

I've run poly on a few front end jobs.
Never had a problem. I like the difference in ride.
Never had one problem with squeaks like some say.
I'm definitely a believer. And will run them again.

I did my Challenger with a full front end rebuild kit from P-S-T. The car handles much better than it ever did. P-S-T uses polygraphite that they advertise does not squeak, and I can attest it lives up to the claim.

The lower control arm was designed to be a press fit with the rubber bushing. A poly bushing does not have the ability to hold tight to the shaft and will allow fore and aft movement. Many will say the torsion bar and the strut rod will prevent any movement. But, I don't want to trust it. I have used Poly bushings every other place in the front end and it seems to work great. The problem with the factory rubber bushings is they would wear heavily over the years, get oil soaked and had to be replaced more frequently. It is not an easy job as everything in the front end has to come apart almost, then the bushing requires a press and the know how to remove and install without damaging the control arm or the new bushing. I would not see any benefit to poly here at all, put new rubber in and call it good.

the main advantage IMO is the Poly doesn't rot away like the rubber. i ran poly's in my 68 Charger for years with no issue. But that was before they were blackballed for some reason. The other comment I'll make is we seem to have forgotten how to make rubber suspension components that last. in my experience i have seen bushings and grease boots start to fail in 3-5 years

Some benefit for sure, less deflection of arm, but not much.
Rubber will isolation noise from tires.
Problem tends to be with the rubber used in recent years, as with engine mounts.
If you find oem or older moog is great

poiy is all i use. and install for costomers.

definatly use them in the lower control arm for better handling !
.

i have seen rubber bushings develop cracks in less than three weeks ! they were the moog brand, and that was almost 20 years ago. tie rod and ball joint boots from moog as well that long ago.
this is why i haven't liked that brand for a very long time !
if one has access to a lathe, delrin is a very good material to make bushings out of. way better material in my opinion.
just my personal experience as a machinist with over 50 years experience. your mileage will vary.

I have good luck with NOS mopar bushings. I think they are better than the new China/India rubber quality. Never cared for poly.

Another option: Nylon bushings!

https://firmfeel.com/collections/tu...shings-a-b-e-body?variant=44601471828286

What’s the deal with the nylon? Nothing in the description telling advantages, never heard of those.

I have the nylon bushings installed them 10+ years ago, no squeaks and stiffer than urethane supposedly.
They were only a few dollars more than urethane. I think Dick Ross recommended them to me.

Never heard of the nylon. I'm surprised to hear they hold up so well. I would have thought they cracked eventually. Looking back on my rebuild I went with stock style bushing there and polygraphite everywhere else. I largely based my decision based on the A body guys here. https://www.forabodiesonly.com/mopar/threads/lower-control-arm-bushings.495665/

delrin is a sort of nylon.
both materials work very well, [better than poly] as i have made several sets of bushings out of those two materials over the years.
long life, no squeeks, oil proof/resistant, and the material is inexpensive to buy in "sticks" if you are making your own bushings. [i realize not everyone can make their own bushings, or have access to buddy's that can do it for them]

Problems with the stock style bushings are typically from improper setting of the ride height. The bushings are to be at rest at ride height, not with tension on them due to the bolts for the shaft being tightened prematurely. The result is they will crack and or or more likely tear. Oil leaks deteriorate the rubber and so does father time. Use nos bushings, better yet look for the pin and bushing kits that mopar sold for years.

I doubt very much that using some other lca bushing would improve lap times in either autocross of high speed laps, but they do add harshness to the ride no matter what. I would never recommend aftermarket vs nos

Appreciate the replies, sounds like a mixed bag.
If all the new rubber parts are garbage, maybe poly is the way to go.

Any opinions on the ProForged parts in the original link?

Same here. I have a pair of NOS ones put away , uppers and lowers