Urethane vs Rubber

[93svt#2779]

I am in the process of rebuilding my suspension, and am looking to replace my worn bushings.

I am wondering what your opinions are between rubber bushings and the urethane ones. Rubber bushings are getting hard to find , and when you do find them, they are very pricey. Urethane bushings are everywhere, and are very cheap, yet claim to be superior to rubber.

What do you think?
Which would you use?
Which would you prefer?
All opinions welcomed, thank you in advance!

[Goose17]

I'm new to 93 Cobras and don't have mine yet, but I've got 4 Mustangs already and I've done some suspension work on my 11 GT500. The factory puts rubber bushings on the cars to minimize NVH. The rubber bushings provide the quietest ride, but easily deform under heavier loads. This is why aftermarket suspension product use urethane. Urethane will be a little noisier, but offer much better performance.

[93Cobra#2771]

I would go rubber, especially in the upper and lower rear control arms. Urethane in the rear will cause binding as the suspension compresses. Go to maximum motor sports site and study up.


Richard White
Reproduction window sticker guy

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[BrentE]

I used the Energy Suspension urethane bushings. They are a bit more firm and they last a lot longer than rubber, but the have some drawbacks. One, the swaybar bushings can be squeaky if they are not lubed. They bind a bit on dry metal and then squeak when they break loose. I got a big needle to force grease under the swaybar bushings and that seems to take care of it, but it is a bit of a chore, and needs to be redone with every oil change.

The second issue can be harshness if you get some with too high of a durometer rating. The car may handle like a slot car but you will feel every pebble in the road. Make sure you get a set that is appropriate for street use unless you are racing. I haven't looked in a long time but I am pretty sure they have different sets with different hardness ratings, marketed from "street" to "race" type of thing.

[93svt#2779]

Brett, did the Energy Suspension bushing kit that you used come in different "hardness" for each application, or were they all about the same?

Thank you guys for your feedback, it is appreciated.

[BrentE]

Brett, did the Energy Suspension bushing kit that you used come in different "hardness" for each application, or were they all about the same?

Thank you guys for your feedback, it is appreciated.

It has been a few years, but if I remember correctly, I bought a certain level of hardness and it was consistent for all of the pieces that made up the kit. You could also buy the different pieces separately and choose firmness for each type. As I recall I bought a set that was for high performance street use, but they also had full race sets offered.

Like I said it has been a while. I will see if I can find the receipt, I keep most things like that in a file (assuming I can find that file...)

[BrentE]

I just looked at the Energy Suspension website, and I see that their lineup has changed a bit. They used to offer like 5 or six different colors, but now only have black and red. The difference is the black ones are graphite impregnated so will be somewhat self-lubricating. I would definitely go with the black ones. Also they now have swaybar bushings for the Mustang that have grease zerks and are much easier to lube. I am thinking about buying a set of those and switching mine out. Mine are not worn out or anything, they really are durable, but having the zerks looks like a very good thing to me.

[93svt#2779]

Thank you Brent.

I have actually started to purchase a few bushings, separately, so it will cost me! I decided to go rubber on the hard to get to bushings.
I ordered all of the spring insulators bushings in rubber. (that was expensive)
Front lower control arm bushings in rubber.
Upper strut mount bushings in rubber.
Polyurethane bushings for the sway bar and end links. (came with the Eibach kit)
Polyurethane steering rack off-set bushings from BBK.

That's most of the bushings I have purchased so far, have not got into the rear-end yet though, so I will be buying more i'm sure.

[BrentE]

Rubber is great, especially when new. It is quiet and does give a better ride at first. My issue is the rate at which the rubber degrades and wears out. The high quality urethane bushings from a reputable company like ES will last about forever... you just have to choose carefully so you do not end up feeling like you are riding on a surface full of large pebbles all the time. A compliant urethane that is lubed is, for me, a great choice. If you are willing to spend the bucks on rubber, and willing to spend again to replace more frequently, it is a great choice... I am just too cheap for that. I want to get it set once and have it stay consistent for as long as possible. That is really the urethane advantage, whereas rubber offers comfort, quiet, and OEM status.