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Not happy with PST poly graphite lower control arm bushings

StrokerSpanky

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There's nothing to keep the control arm from sliding rearward on the center shaft and letting the bushings squirt out the front and self destruct. Lasted 7 months.
 
Wow, nice introductory post. :eek:

Any chance of some background to how they were installed before racing off and blaming the product?

Pictures will speak 1,000 words.
 
No he's right they are crap.....
 
Wow, nice introductory post. :eek:

Any chance of some background to how they were installed before racing off and blaming the product?

Pictures will speak 1,000 words.
^^^^^^^^^ This, plus have you contacted the manufacturer or supplier ?
 
There is a lot of advice out there to NOT use them for that very reason - they do not secure into the LCA like the rubber ones do.
 
^^^^^^^^^ This, plus have you contacted the manufacturer or supplier ?
Well, he did post this on PST's vendor page on here......and usually someone from PST replies in short order.....
 
There is a lot of advice out there to NOT use them for that very reason - they do not secure into the LCA like the rubber ones do.
That's all very well, but to use your very first post on a site to slam a Site Vendor without showing any evidence or good explanation as to the installation process is downright rude IMHO.

Geez, whatever happened to "Hi guys.....got this car and have a few problems"? :rolleyes:
 
When you have a moment please private message me all of your information and I'll look into your issue. As for the lower control arm bushings if you're using the poly graphite style you would need to reuse your inner and outer shells. In Chrysler's design the lower control arm bushing is not designed to hold the lower control arm in place. The original rubber style bushings are vulcanized to the inner and outer shell and that in itself is not designed to bear the weight and hold the control arm in place from moving forward and aft. What essentially holds the control arm in place is the strut rod and strut rod bushing. If you have premature failure of the strut rod bushings this can lead to issues with the lower control arm bushings that you have described. Please feel free to contact me and we will work with you.

We are here to help but you need to reach out to us with your issues either direct through our website or by PM

Thanks
James From
PST
 
In Chrysler's design the lower control arm bushing is not designed to hold the lower control arm in place. The original rubber style bushings are vulcanized to the inner and outer shell and that in itself is not designed to bear the weight and hold the control arm in place from moving forward and aft. What essentially holds the control arm in place is the strut rod and strut rod bushing.

Thanks
James From
PST

Have you ever tried to hold a lever close to one end and apply considerable force to the short length extending past your hand? The other end of the lever needs to be supported or it will move in reaction to the force applied.... Yes the bushing do in fact bear a part in controlling the for & aft movement of the control arm in addition to controlling/allowing the pivoting movement of the arm.... I used poly LCA bushing once... And only once....

On a GM where the LCA bushings are huge chunks of rubber I see the value, not to mention in that design the bushing only controls the pivoting motion...

A Mopar bushing has so little deflection by design there's no reason to use poly even if it did control the for/aft movement...


Normal GM LCA bushing, lots of rubber...
Screen Shot 2021-07-19 at 9.42.16 AM.png


LCA bushing for 64-72 GM A body.. Even more rubber..

Screen Shot 2021-07-19 at 9.43.17 AM.png

Mopar LCA bushing a thin band of rubber..

Screen Shot 2021-07-19 at 9.44.17 AM.png
 
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As similar discussion in poly lower control arm bushings seems to come up every couple of months and they are pages on this on both forums. But I am I will have to disagree in respect that vulcanizing of the rubber to inner and outer shell in some degree hold the control arm from moving forward and back.

The member 72BluNBlu post on the FABO pretty much sums it up. Below is one of his :

Improperly installed parts fail, everyone knows that.

If you install your poly bushings properly, and pair them with strut rods that are the correct length, the issues you describe are simply not physically possible.

And without a strut rod installed, you can pry the LCA off the back of the pin with the OE bushings too. The rubber will fail. The idea that a rubber donut wrapped around the pivot pin positively locates the LCA is just silly.

I’ve run poly bushings and adjustable strut rods on the street for over a decade and tens of thousands miles on multiple cars. Guys on this board with poly LCA bushings have run their cars at autoX events, on road courses, and the strip without any of the issues you describe. That much movement would result in massive changes of the caster angle and the vehicle would be completely unstable. It just doesn’t happen when the parts are installed correctly.

Poly LCA bushings have been available for a very long time now, decades even. They are produced and sold by all of the respectable aftermarket companies that make handling components for Mopars. Firm Feel, BergmanAutocraft, Hotchkis, etc. And they’re used in pretty much all of the high performance handling builds, used on tracks, road courses, autoX’s, etc with great success. Dozens of members here use them without issues. Sure, they can fail if they’re not installed or maintained properly, but so can every other part on the car. They would not still be available from all of those respectable companies decades later.
 
I noticed all that when I put mine together and I had to trim the poly bushings on the strut rod to prevent said movement. I could have gotten adjustable struts but had spent enough already. Was I happy about it? No, did I wish I went stock? A little, but I had it all and couldn't return it so in it went.
 
The only problem I've ever had with poly bushings is squeak......and yes, you need to have the stock shells or buy some if needed. Seems like iirc, they are for sale from various vendors. Been awhile since looking into it.
 
Well I've got the PST poly graphite bushings on mine as part of a full front end rebuild and have had no issues in 3 years and 8,000 miles. No squeaks either, nice and quiet.
They must have been installed correctly as I did them myself :).
 
Well I've got the PST poly graphite bushings on mine as part of a full front end rebuild and have had no issues in 3 years and 8,000 miles. No squeaks either, nice and quiet.
They must have been installed correctly as I did them myself :).
I think after a lot of complaints about squeaks when the poly stuff first came out changed the way they are made.....I've heard mention of graphite impregnated bushings......?
 
That is what we offer in our poly bushings. These are know as Polygraphite. So if you were to cross section a bushing of ours you will see graphite within it.
 
Polyurethane squeaks, I don't think Ploygraphite does or at least have never heard of it doing so.
A lot of Prothane products I've used in the past squeaked like an old spring bed in a cat house.
 
I had squeaks from urethane bushings before. It was about 2 years ago I was consolidating some parts and I found an unmarked jar of a goo that looked like thick Vaseline or Mentholatum. It was bushing lubricant. The stuff is thick and doesn’t wipe off your hands well. I took my leaf spring shackles apart and coated the bushings with this stuff and boom....no more squeaks at all.
 
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