2nd Gen Non-Engine/Transmission Downsides to polyurethane control arm bushings?

[abranz]

Just posted a question regarding R&R of the control arm bushings. I appreciate everyones input. I've read many posts on this and many people choose energy poly bushings. Are there any downsides to these as opposed to the stock rubber bushings now that some of you have miles on them? Thanks Tony

 

[AMink]

I have read that they are louder and provide a harsh ride. I didn't notice that on my 97. I would think the pluses (longer life, less slop, cool colors) would outweigh the negatives.

 

[Dave M]

I'm with "AMink" on this. I've had mine on for about 3 years now and don't notice any difference in ride but my 1 ton dually is stiff anyhow without a load in the back so I don't think I would notice if the ride were stiffer.



They will probably outlast the truck for any slight difference in ride and I believe the stock bushings also cost more.

 

[CumminsPower98]

I built my own arms and used "Johny Joints" on one end and standard "T" poly bushings on the other end. I did notice a tiny bit more feedback from the road maybe but nothing to worry about. I would certainly do it again without question. I have put 130k miles on them so far with no trouble.

 

[Vaughn MacKenzie]

I'm glad to find this thread because I have Energy Suspension poly bushings that I plan to install on the '96 next week. I'm more concerned about whether or not they'll squeak.

 

[abranz]

Well, the reason I ask is I made the mistake of googling "poly bushings" and read about an hour of complaints from people about them squeeking, not allowing enough flex for the suspension as it was designed, etc. Many of the post were positive, especially race-sport car enthusiasts. Then I was not sure what to do so I thought I would ask fellow TDR members. The job is big enough I really don't want to do it twice in a short period of time.

I appreciate the responses.

Tony



I read this, what do you think?

Polyurethane Bushings

 

[RSimmons]

I have had them on cars and trucks in the past as ,well as my current truck ,and they do squeak a bit. With a gas burner you may hear it slightly with your windows rolled down. With the diesel, you'll never hear it.

 

[CumminsPower98]

All of my joints are greaseable except the axle ends on the upper arms. I have had no squeaking even in the two that don't take grease. I lubed them up good when the went on. On my initial install I used silicon grease, which is the same or very similar to what Energy uses as far as I can tell. Of course there are many different grades of poly bushing so I guess I really can't compare what I have to the Energy stock replacements.

 

[sleon]

When you replace them w/rubber or poly are they pressed on?

 

[MRose]

Had mine for two years, no noise.

 

[SRath]

I have always been a fan of polyurethane products, especially polygraphite, which all of Energy suspension's black colored products are. The red ones have no graphite for lubrication. Squeaks are not an issue for me, but I only use the black polygraphite ones.



However, just mentioning polygraphite or polyurethane on another website I participate in (NastyZ28) gets all kinds of hoots and catcalls. They prefer del-a-lum (greaseable aluminum and delrin or nylon bushings. Kinda pricey, but nice).



On NastyZ28, many folks are very interested in low-slung, high g-force, cornering and handling. You can make up your own mind, I'm sticking with poly unless I can do something much better like CumminsPower98 did, but here is one interesting bit of point of view another member there posted regarding poly:



A word about polyurethane bushings



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It seems that as long as I have been working with cars there have been questions about polyurethane bushings. This is probably due to their relatively cheap price and constant advertising in the car magazines. After more than 10 years in the automotive business I have come to some conclusions about bushings.



The major problem one hears about when using polyurethane bushings is squeak. But the squeak is not the real issue it is merely a symptom of a larger problem.



Polyurethane and its variations (like poly graphite) have no business being used in any rotational bushing application. This means leaf springs, a-arms, trailing arms, strut rods ect...



The basic reasons are:



1) A rubber a-arm bushing does not rotate in the mount. Rather the movement comes from the rubber flexing between 2 metal sleeves as the a-arm travels up and down. This is evident if you remove the springs from a rubber-bushing car while it is in the air. The a-arms do not drop.

With a poly bushing there is no flex (or metal sleeves for that matter) so it is forced to rotate in the seat. The problem is that the rotation is not a clean motion. It's jerky, and inconsistent. The squeak is a symptom of suspension bind, but just because you don't hear it does not mean that there is no bind



2) Over time all Polyurethane goes through what is called "cold flow". Without getting into the chemistry, the urethane bushings are more of a very dense gel than a solid compound. Over time rotational bushings go from a round shape to more of an oblong egg shape. Needless to say this is a bad thing.





You will never see urethane on a real roadrace car because of these conditions. Serious roadracers use either mono-balls (also called spherical bearings), or a metal bushings with some type of lubricating strip.

Monoballs while the"truest" bushing are generally a poor choice for street cars as them are noisy and wear out relatively quickly.

 

[Vaughn MacKenzie]

I purposely got the black ones because of the polygraphite.