replacement suspension bushing advice - poly vs rubber

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lil red

lil red

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just wondering what people think of polyurethane suspension bushings vs using regular OEM rubber replacement parts. I'm looking at buying the front end replacement kits from energy suspension or PST and unsure of what material to choose. I also see where energy suspension also sells poly cab mounts.
Just wondering if anyone out there used the poly, and what the resulting performance or ride was, thanks fellas

P.S. I noticed that PST sells a polygraphite infused material, to me this seems better than the urethane...thoughts
 
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If you’re planning on keeping the stock suspension components, ie, UCA’s, strut rods, LCA pivot pins etc, use rubber.

If you’re willing, or want to use adjustable strut rods and greasable LCA pivot pins, then use the poly bushings. Properly installed, the poly bushings will outlast and outperform the OE rubber. But they don’t work exactly the same way, so, you need to account for that on installation.
 
72bluNblu said:
If you’re planning on keeping the stock suspension components, ie, UCA’s, strut rods, LCA pivot pins etc, use rubber.

If you’re willing, or want to use adjustable strut rods and greasable LCA pivot pins, then use the poly bushings. Properly installed, the poly bushings will outlast and outperform the OE rubber. But they don’t work exactly the same way, so, you need to account for that on installation.
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Im replacing the factory bushings and using all the original components. There really isn't a big difference in price between OEM and poly in the PST front end kits
When you say they dont work the same, do you mean the ride and handling is different, stiffer , etc.
 
lil red said:
Im replacing the factory bushings and using all the original components. There really isn't a big difference in price between OEM and poly in the PST front end kits
When you say they dont work the same, do you mean the ride and handling is different, stiffer , etc.
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Well yes, the poly is less flexible. So, less slop in your suspension, which is good, you’ll have better, more accurate handling. But of course that also means more road noise/vibration etc.

But the bushings themselves work different. The poly bushings can spin in their shells, and the pivot pins can spin in the bushings. That’s not like the rubber bushings. The rubber bushings are friction fit into the shells, and all the suspension movement is flex in the bushing, not anything spinning.

The other thing is, the stock, non adjustable strut rods depend on all the flex and slop in the rubber. They’re not exactly sized, it’s like “one size fits most”, with the slop and flex keeping things from binding. The poly LCA bushings don’t have that slop and flex. So, the strut rods have to be the right length, and that’s not necessarily the stock length. Plus, since the pivot pin can slide, the strut rod length is even more critical. Same for the pin being able to spin, now you need lubrication.

I like the poly bushings better. But in my opinion, if you want them to work right, they should be installed with adjustable strut rods and greasable pivot pins. Do that and they’ll outperform and outlast the rubber. Don’t, and you’ll be like the folks complaining about squeaky bushing that let the pins slide. It’s not a problem with the bushings, it’s bad installation.
 
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I vote for new rubber. Poly is harsh and can squeak (most of the time) and is harder to install back to spec. Thats just my experience, but I do run poly sway arm bushings.
 
Poly will not squeak if properly lubricated. I use the cheapest poly bushings you can buy and I’ve run them for tens of thousands of miles with no issues at all on a couple different cars now. Grease the heck out of them on install, and use greasable LCA pivot pins so you can grease them periodically. That’s all you have to do. They just require different installation and upkeep than rubber.

When I pulled the poly bushings out of my Duster and replaced them with Bergman Autocraft Delrin LCA bushings, the poly looked brand new still. That’s another option too, Peter Bergman, member @GMachineDartGT, sells Delrin LCA bushings. No grease needed, and even less flex and give than poly. But again, the pin fit has to be right and adjustable strut rods need to be used.

But it depends on application. If this is just a cruiser and you want to keep the suspension components stock, stick with rubber, because you probably won’t be happy with the poly bushings and stock components.
 
thanks fellas, ill stick with factory for most front end components, maybe poly for the front sway bar bushings (they also sell poly cab mounts). I thought about machining my own out of water lubricated Thordon or CIP but lord knows what type of mess id have ...... better stick with OEM.....thanks again for the advice
 
72' pretty much covered it. Stock rubber deflects in a certain range of motion, that's why it is important to keep it all loose and torque it all together at ride height. Poly pivots, and you should torque it too at ride height but that depends on the bushing set up. Lube is your friend with Poly.

I used Polyurethane cab bushings on my 79' Ford 150 SWB 4x4 and they are fine. They won't flex as much as rubber but I didn't notice any extra NVH over other trucks I've ridden in with rubber mounts. I have a built 460 sitting on Poly mounts too.
 
I'm running stock stuff and after much perusing of the forum opted for rubber on everything except poly strut. I had to machine the poly to get my LCAs in the correct position. I also went with the problem solver offset moog UCAs that put more caster into the wheel... i will be using poly on a large front sway and will run a small rear. I'm going for quiet street ride... mostly. Exciting stuff. . can't wait to get through paint.
 
pishta said:
I vote for new rubber. Poly is harsh and can squeak (most of the time) and is harder to install back to spec. Thats just my experience, but I do run poly sway arm bushings.
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Me too.
I inspect the front suspension components. If the original ball joints, tie rod ends, etc.are good. I reuse them. One of the problems with all-in-one kits is you have little control over quality. The LCA bushings are usually beat and I get Moog rubber. The rubber is so thin there isn't a whole lot gained with poly unless you are road racing. I also use Moog offset UCA bushings to get more caster.

However, I use poly for for the sway bar links and bushings.
Also....rear spring shackles get replaced with poly I source from Mancini Racing. That might be an area that gets overlooked.

This is what I do on my junk because I drive them, not race them every day.
 
hey leblanc, gonna try to make Moncton this year.

again, like always thanks a lot for the advice, like kosmic and dano the components like tie rod ends, ball joints CA bushings, i'll inspect and replace worn with factory rubber but im gonna try poly for the front sway bar bushings, cab mounts, rear spring eye bushings and cross drill the bolts and add grease fittings. the old truck has been undercoated with used oil since it was new and the old rubber bushings are swelled out like mush
 
lil red wrote: ''hey leblanc, gonna try to make Moncton this year''.

I am sure you won't regret it!!!
Check out their website, dates are July 4-8th this year.
 
Does anyone know if oem rubber front sway bar bushings are still available? I tried pst, a moog website, Jegs, summit no longer available. I wanted to have an option to the polygraphite front sway bar bushings.
 
LovetheA's said:
Does anyone know if oem rubber front sway bar bushings are still available? I tried pst, a moog website, Jegs, summit no longer available. I wanted to have an option to the polygraphite front sway bar bushings.
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contact Firm Feel in Washington. They specialize in Mopar suspension stuff.
 
pishta said:
I vote for new rubber. Poly is harsh and can squeak (most of the time) and is harder to install back to spec. Thats just my experience, but I do run poly sway arm bushings.
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Agreed, first restoration all poly and exactly that. It is crisp and you can feel the road but it is harsh and will squeak in damp weather. Now I use poly for the rear springs and front of the LCA brace arms and rubber for everything else.
 
Poly in the front end with rubber in the strut rod bushings and front leaf eyelets...the rest all poly.


Think about what a pain in the *** changing the lowers is for a novice..then consider what an oil leak can do to a oem rubber bushing... trust me, you'll be thanking me 10 years from now especially if you have a slant six 'prone to leaking oil at the head'.

I did my car up this way about 18 years ago I've never had to do anything with any bushings since
 
For boulevard cruising go OEM. For spirited Handling and sharper feedback, go poly.
 
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