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Prothane vs Rubber bushings

rockchucker

NAXJA Forum User
Location
Colorado
I am getting ready to instal a 3 inch lift on my 96 cherokee and wanted to replace the rubber bushings in the rear leaf springs, shackle, upper control arms and the sway bar. I have talked to a few Jeep friends and some say stay with new rubber and others say to get polyurethane. The cons I have heard about polyurethane is they will make squeaking noises. If you hit hard they will dent and not return to the normal shape. The thing I noticed is that it is easy to find kits with Polyurethane but not rubber unless I am not looking in the right spots. Any insight would be great.:read:
 
Poly is fine for the sway bar,they are not bad in the leaf springs/shackles,but do not use them in the control arms.
 
not sure if RE's kits fit other leaf springs, control arms, etc but they sell them on their site. Also, rubbers you have to press in with a 20T press as polys slip in, making in a helluva lot easier. I agree though, use the polys in sway bars, leafs and shackles but not in control arms
 
Thanks for the info guys, I got a set of rubber for the upper control arms and will press them in, I am going to pick up poly for the rear springs and the sway bar. Next question is what motor mounts are the best. I found a set of Iron man motor mounts. I am just not wanting to cut corners and this is also relevant to the issue with rubber vs poly.
 
Thanks for the info guys, I got a set of rubber for the upper control arms and will press them in, I am going to pick up poly for the rear springs and the sway bar. Next question is what motor mounts are the best. I found a set of Iron man motor mounts. I am just not wanting to cut corners and this is also relevant to the issue with rubber vs poly.

Yeah, I realize the thread is old. But as I'm at this exact same place, I'd like to know if after having these on for a year plus, how did the poly's work out for you.

...I bought the Energy Suspension rear leaf & shackles bushing set before I'd read anything, and now I'm wondering if I should use Moog OEM-style instead. This is hopefully a New Year's weekend project.

(My '96 is mostly a DD mall queen, but we camp-hunt-fish/rec-reate other stuff too ...the new, still-not-on, leafs are UC height-QT HD Crown's.)

So: how did this combo work for you? Any regrets?
 
I put polyurethane in my control arms, bump stops and sway bar last summer and I have no complaints at all. Handling is good, and no unwanted noise...I would no hesitate to use poly again.
 
I hate poly, it squeaks. Won't ever use it.

I realize not everyone will have squeaks, but it depends on how and where you use it. Since I've already been driven crazy by the noise, I won't take the chance again.
 
So you're saying those poly window net mounts I just bought aren't going to work?
 
So you're saying those poly window net mounts I just bought aren't going to work?


Probably not.

flipoff.gif
 
I hate poly, it squeaks. Won't ever use it.

I realize not everyone will have squeaks, but it depends on how and where you use it. Since I've already been driven crazy by the noise, I won't take the chance again.

I think I've read 100 plus threads on this lol. But other than people have opinions, and strong ones ...I dunno if I know all that much more about poly vs. OEM choice-wise then I would have if I simply flipped a damn coin LOL.

I'm looking for some balance, considering that I already have the leaf packs (new Crown Upcountry replacements ...the QT HD OEM packs), and already have the Energy Suspension rear leaf poly bushing kit (I only ordered 'em because it was a "good deal" IF I bought them with Reflex 911027 rear shocks ...and then the seller cancelled on the shocks - didn't have 'em - and had already shipped the poly kit when I called to cancel that), sitting on the floor of my garage.

But I picked up some unexpected income this month (still waiting for the checks to come in, but they're reliable clients), so I'm seriously considering an HD Engineering shackle relocation kit as part of the project ...which that, and the UC springs, should make for a 2 inch lift (which I've decided I'd actually like to have, since I've now seen enough pix of XJ's with 2" lifts running 235/75R15's, which helped me think it won't look totally stupid ...especially important, as I just shod it with that size new GY Wranglers on TJ Canyons, so I'm not changing that part of the equation).

Does a shackle relocation kit make a difference in whether poly bushings are a bit more acceptable?

Or what about shackle sliders instead (they're not that much more expensive, and I)? Would that make a difference in the use of poly on the packs (after all, you're eliminating the shackle)?

Its the "how and where you use poly" that is my problem, lol.

Here's what I think I do know.

Ease of installation? - No contest. Poly wins. A little lube and a BFH and you're good. No press. No fuss. No muss ...and I already got a BFH.

Squeeks ...make sure to lube the holy crap out of poly during the install, and add this an an item to your regular maintenance lubrication list. And do NOT over-tighten anything (i.e., the bushings, not the u-bolts) until you have the vehicle back on the ground, with the full weight of the vehicle on the leafs. And maybe the squeek issue is mitigated to "down the road". Maybe.

Longevity? Poly lasts longer, maybe ...if it was a quality kit, and if it was installed correctly, yada-yada. That said: rubber lasts "long enough" (years).

Flex? Who the hell knows lol ...there's some very, uh, conflicting opinions on this. I think there's a consensus that poly should not be used in the sway bars, and the lower control arms (not that I care about that right now: the question is whether they're okay in the leaf packs fr/rr or one or t'other).

As for acceptable poly "locations" re: leaf springs ...here's what I think I have learned so far, from various comments.

Front rear leaf bushing? - Poly is probably okay. It depends upon whether leaf twist is or becomes an issue (the trick being whether you can pre-determine this lol).

Rear rear leaf bushing? - Maybe. Maybe not. Who knows. See the "leaf twist" issue, but do you get leaf twist with shackle sliders? Dunno.

Shackle bushing? - Probably not. Sliders eliminate shackles though.

So. Basically: I got nothin'. Yet.

...but boy-oh-boy, am I getting really good at searches.
 
Uh. My last comment was moderated? Why would that be?

...it was a long comment. With several links (to discussions here and Cherokeeforum, and to a couple of mfr product sites): does that throw a comment into moderation? TIA.
 
No can make your choice for you. There is no right or wrong answer. Performance street cars use poly to stiffen the suspension (components, not spring rate) for better feel and handling. In a 4x4 you want things to be more loose, both for some flex and to lessen the stress on parts, because it is going to flex. Less deflection in a joint puts more stress on mounts and arms and the main leaf on the spring pack. Theoretically poly can last longer than rubber because it's harder and more durable, but in the real world it can wear out quicker because of the greater deflection that we ask of it. Rubber control arm bushings and rubber spring eye bushings can last a very long time. As far as the squeak, it's a possibility and can be likely to eventually happen, but it might not.

So, when you debate whether or not it's a good idea to use poly bushings, what is the argument for how they are beneficial? What performance or longevity benefit will you get out of the poly bushings? This question asks more than just some internet testimonies saying "I used them and they were fine".

BTW, I'm not saying not to use poly bushings anywhere, but you need to have a reason for doing it.
 
Thanks goatman; you helped in understanding more about the reasoning behind making the decision.

In this case, through a screw-up on the part of the seller, I own the bushing kit already.

I also don't really offroad it; the XJ's primary purpose for us is on-highway/paved road snow-driving (we camp & fish with it, but the worst it will ever see is an occasional logging road). We have a TJ for going back-country (essentially, we drive the wagon all winter and the Wrangler all summer).

So the "stress" and flex I ask of it is ...pot-holes (your tax dollars at work lol).

One argument I've read that actually would matter to me (all other things being equal), is that installation is easier ...because you don't need a press to get the things in the leaf-eyes.

From your reply ...at least I don't think I would be totally screwing the pooch if I just go ahead and put the things on now, as a matter of convenience alone ...and with the expectation that I might be going back in later, and replacing the bushings with some more forgiving OEM compound if I (or my wife lol) hates 'em.

I'm also adding a shackle relocation kit to this "equation" btw.

I kind of decided that a couple of inches (UC leaf packs are supposedly 1 inch, and the relocation kit maybe another 1 inch) additional to the XJ dd ride height might be desirable/acceptable (not sure which to "go with" lol) ...as much due to "opening up" the shock absorber choices (I'd like to use Reflex monotubes ...and the commonly available ones are for an inch-plus more than the stock height/range).

Tnx again.
 
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