Poly Lower Control Arm Bushings VS Rubber

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79JON

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Ive been searching all over to see why people say not to use the Poly LCA bushings and put Rubbers in, but I cant seem to find a clear answer. I bought the Energy Suspension Poly bushings for my Duster and Im actually about to start sand blasting and reinstalling the LCA's. I saw a few people say go with the MOOG bushings just for the LCA. But why? Is it just a personal prefrence to how it rides? or are the Polys not built right for the LCA? If anyone can explain that to me id appreciate it. Thanks!
 
I know alot of the guys have complained about squeaking from the poly stuff for LCAs.

But, some also say that only polyurethane squeaks and polygraphite does not.
 
They WON'T work their way out, and CAN'T. I used them on my 72 and they were fine and didn't squeak (much).

Something to keep in mind when installing is that you typically must re-use the inner and outer shells of the old rubber bushing. Essentially you are just replacing the rubber part. This has the advantage or disadvantage of not requiring the old "can" to be removed from the LCA. They require a bit of work to remove, but then again getting all the old rubber out can be a messy job. Same with the inner sleeve. It's usually stuck on the pivot shaft, but you have to clean it off. I think somebody makes/made pivot shafts with a larger OD which fit the bushing directly.

Another potential issue is the "head" of the poly bushing is bigger and may position the LCA slightly more rearward. This will tend to reduce caster. I don't recall this being an issue, but the last set I installed was 18 years ago. The length of the bushing could easily be adjusted with a belt sander if need be.

Are the poly bushes better than a quality OEM type? Maybe, but probably not much. If your old bushes are in bad shape replacing them with anything will make a huge difference. Replacing a good OEM bushing with poly probably won't make a noticeable difference. For a road racer Nylatron or even solid bronze bushings would be best, but they would be noisy on the street.
 
C130 Chief.. Thanks.. Thats basically what I needed to hear. If I still go with the Poly's it will save a TON of time of me trying to chisel out the sleeve and stuff. Luckily my Energy Suspension kit comes with the Poly bushing and the inner sleeve. So basically all I have to do is clean the rubber out. Im kinda on a budget and since this kit already has the bushings I can save alittle money rather than going to pay another 30 bucks on some MOOG ones.
 
my experience is that they dont woek their way out if the LCA. that being said, the do move in and out a little, causing some really odd problems.
i pulled mine after about 15k, and the inner pivot literally fell out. used energy suspension.
after switching to rubber, most of ny handling issues were resolved until i blew the car apart dor a full resto.
an added benifit is a slightly stiffer efective t bar rate.

michael
 
dusterbd13 said:
my experience is that they dont woek their way out if the LCA. that being said, the do move in and out a little, causing some really odd problems.
i pulled mine after about 15k, and the inner pivot literally fell out. used energy suspension.
after switching to rubber, most of ny handling issues were resolved until i blew the car apart dor a full resto.
an added benifit is a slightly stiffer efective t bar rate.

michael
Click to expand...

What kind of odd problems ? Besides the noise
When I changed mine rubber fell out , or what was left of rubber fell out , outer casing was not hard to remove
Still have the energy bushings , maybe next time i'll use them
 
Take this for whatever its worth.

I rebuilt my suspension over the last two weeks and researched this topic on here and other forums. This was my take:

Poly bushings squeak after X amount of time and the only real solution is get a silicone spray to lube the bushings every month or so.

However, look at your LCA, do you think you can effectively lube that bushing when its bolted up? If no(which was my conclusion), do you want to disassemble that LCA each month? Or can you live with squeaks?
 
I first put my car on the road in 1997 - I rebuilt the front end at that time and had all poly except for the LCA's

12 years later i rebuilt it again - guess what was the only bushings showing wear? the rubber LCA's!

I went this time with a just suspension pivot shaft, since it's od matches the poly ( no need for an inner sleeve, and just re-used my old outers.

No squeaks ever if you install them correctly.

Here is the poly vs rubber, they will never come out, ever.

DSC_1357.jpg
 
I had a set work there way out and reusing the shell from the old bushing is a pain in the ***.
 
Still not sure how they can work their way out. The bushing is captured between the LCA and the K-member. Where did it go?
 
they dont come the whole way out, as they ARE capyured. but they allow the LCA to walk on the pivont shaft. mine moved aroud 1/2 inch or so. which is a lot. makes the car kind of squirrley, impossible to align, and feels very unpredictabl;e when pushed hard.
 
and you think the smaller rubber bushing ( that is not bonded to the shell ) will hold it all in perfect alignment??

I dont know what poly ones you used, but the ones I put in ( just suspension ) have a mushroom type top that eliminates all type of fore / aft movement when installed. it cannot move.
 
the only thing they are missing is a flat to hold them during assembly.

if you look at the attached pic I had put up the new ones JS has come with a flat to put a wrench on during installation.
 
oh okay. i see the flat your talking about in your picture....but im not understanding right now on why the flat is needed.....?? why do u need to hold it with a wrench?
 
Rebuild the front end with rubber, and drive it for another 30yrs.
 
mopardude318 said:
oh okay. i see the flat your talking about in your picture....but im not understanding right now on why the flat is needed.....?? why do u need to hold it with a wrench?
Click to expand...


the poly is lubed up so it slips, the flat is there to get the proper torque on the LCA pivot shaft nut
Johnny Dart said:
Rebuild the front end with rubber, and drive it for another 30yrs.
Click to expand...

maybe with the original rubber, but my last ones were shot after 12 years... i dont know if its the new junk rubber they are making or what - but all the poly was fine - but the rubber LCA bushings were shot.
 
My rubber LCA bushing lasted 6 -7 years and they were shot in fact all the rubber bushings were shot . Don't think ANY rubber bushing will last more than 8-10 years , rubber dries out breaks down .
 
When you say that you reused the outers, were you able to just leave them in the LCA and install the shaft and bushing?
 
I cannot see how a poly bushing can stay on a shaft that has effectivly no nut on the end of it or nothing to retain it. The way a poly bushing is designed, it HAS to rotate on another surface, in this case the "stud" (some call it a pin) for the lower control arm. then it is pressed into the "cup" of the LCA. It goes to reason that if it has to rotate on the pin, then there is NO press fit of the bushing onto the pin. Yes, there is more of a press fit in to the cup due to the larger area of the cup surface and press fit tolerance etc but, what then keeps the whole she-bang on the pin? yes the T-bar is located in the other end of the LCA cup on the end with the hex but this should not be expected to hold the LCA AND bushing in place. THere is tolerance in the T-bar fore and aft and after the backwards movement, all there is , is a little circlip to be used as a preventive device to keep it from falling out. Of course nothing moves too much due to the tension of the T bars but it percievably cannot prevent all movement depending on how much force being possibly applied to it.
With the rubber, the bushing is pressfit onto the pin, lots of tension to hold it on there, and then the whole pin and bushiing is pressfit into the cup of the LCA. then the whole deal is bolted to the K frame. THe rubber bushing does not "ROTATE" on anything. It "TWISTS" around on itself because it is rubber. THat is one of the properties of rubber that this can be made to work like this. there is NO rotating of one surface on another. Now, if the rubber wears out, yes then it can move around on itself by breaking up internally but still the bushing shell does not rotate on the pin or the outer shell of the bushing does not rotate in the cup. therefore, I would rather have the rubber in the LCA as long as it is in good condition and is of good quality.
 
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