Replacement Leaf Spring Bushings, Rubber or Polyurethane?

I hope OEM tech is the appropriate place to post this question... I suspect I need new leaf spring bushings and am wondering what you guys would suggest? My XJ is lifted but I did a bastard pack in the rear so I’m still running the stock main leaf (and therefore will need new bushings intended for stock springs).

I did do some searching and see that a lot of people complain about poly bushings only due the characteristic that they tend to squeak. I’ve had poly bushings before and found that they don’t squeak if you lube them really well with the special grease when installing them. Although that was with sway bar or control arm bushings, I assume the same will be true with leaf spring bushings. I have the grease on hand so that’s not really a concern.

Which would you go with and why? There are a few brands of bushings to choose from in both OEM rubber & polyurethane… are there any that are better than others, or any to avoid based on quality control / durability?

Would I need a press or vise to install rubber OEM replacement bushings, since they come made integral with the metal shell? It’s my understanding that the poly bushings will just slide into place, though I’m not sure if they re-use the old metal shells or are made with a larger O.D. to just fit the spring eyes.

Rubber. Every time.
Poly is easy to install and gives a firmer ride. It also squeaks, transmits vibration and is generally harsher.
Rubber can be a pita to install or remove but it will keep your ride comfy, it doesn't squeak and my oem rubber lasted over 15 years and 140k miles.

Red91Laredo said:

Would I need a press or vise to install rubber OEM replacement bushings, since they come made integral with the metal shell? It’s my understanding that the poly bushings will just slide into place, though I’m not sure if they re-use the old metal shells or are made with a larger O.D. to just fit the spring eyes.

Click to expand...

Yes. I bought a 1 Ton arbor press from Harbor Freight and still needed to add an extension to get the bushings installed. They fit tight.

Red91Laredo said:

It’s my understanding that the poly bushings will just slide into place, though I’m not sure if they re-use the old metal shells or are made with a larger O.D. to just fit the spring eyes.

Click to expand...

If you choose poly.. No you don't reuse the metal shells. You remove the whole OEM bushing and tap in the poly bushing.

I like poly. Anytime I have the option of using poly
I take it: with (Bronco) motor mounts, sway bar
bushings, etc. Poly is more durable, easier to install,
and as you say if greased it will not squeak.

Yes, it gives a firmer ride but I consider that a plus.

Sometimes you do need to leave OEM outer shells in place for poly & just burn out the rubber; have to read the directions for your particular app. Poly won't squeak if you rub lots of powdered graphite into the moving surfaces before install. I never had any luck with the gorilla snot but when I switched to graphite they were dead quiet. They are harsher than rubber, and I haven't used poly on an XJ (but may soon, am planning some suspension work.)

I might go with rubber then as I don't really want a firmer ride. Unless the poly bushings will improve handling noticeably? I assume on a Jeep the suspension should be too compliant to feel any actual difference in handling. I'll be installing shackle relocation brackets soon, while the current ride quality is OK I would like to make it better, definitely not any harsher...

In all honesty, I'm all about ease of maintenance. I've installed both rubber and poly bushings, and frankly, the poly is so easy to install I don't even think about the originals, even after making a special tool just for installing the oem rubber, it's still a pain.

The squeak is taken care of with grease, what I did on my buddy's jeep (last one I put new bushings in, mine is coming up after I get my new christmas springs) is this:

http://www.quadratec.com/products/1...oglemerchant&gclid=CIOb49aAs7oCFRFxQgodj3kAbg

It's a greasable bolt (has a zerk fitting) that nicely pumps grease into the fitting and keeps everything quiet. Down in portland you shouldn't have to worry about the #1 cause of squeaks... fine dust.

BulletMaker said:

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http://www.quadratec.com/products/1...oglemerchant&gclid=CIOb49aAs7oCFRFxQgodj3kAbg

It's a greasable bolt (has a zerk fitting) that nicely pumps grease into the fitting and keeps everything quiet.

Click to expand...

Those Currie hollow bolts are 7/16'", made for the upper front control arms, not the leaves.
The rear leaf springs use a 10.9 M14 x 2.0 bolt (much larger than 7/16").
Not sure if hollow bolts, of the right grade, are available for the rear

If you go polyurethane, periodic lubing is a must to prevent noise, especially in a wet climate like Portaland. You need an easy way to apply grease, such as a hollow bolt. Having to pull the leaf to lube the bushing is too much of a hassle.
I have never seen any reason run anything but rubber, no downsides I can see. Punching in the new bushings is best done on a large arbor press or hydraulic press, much easier than trying to beat them in by hand.
Getting the old ones out can be a difficult project.

Trust me, powdered graphite lasts longer than grease, I rebuilt a friend's Valiant w/ "poly graphite" bushings, scuffed them up like the instructions said, greased them liberally, still every driveway apron squeak squeak squeak. When I did my GTI I couldn't get graphite impregnated bushings only red plain poly, I graphited them up & installed dry, I actually transferred that suspension to a Scirocco when I sold it & it was squeak free through two cars & probably 60K+ miles.

yeah, I go with polyurethane bushings, they last a lot longer and grease and oil won't hurt them.

Can anyone who has installed poly leaf spring bushings confirm whether or not they ride firmer than rubber bushings do?

Looks like I can get Omix rubber bushings (all 4) for about $29 shipped from Summit, so I'm leaning towards those, other than being cheap mainly because I don't want to stiffen the ride or add more NVH...

its not so much a "stiffer" ride, but more transference of road vibration.

also, in an offroad application, poly flexes less, requiring the spring to twist more, hurting articulation.

I too like "runnin'onempty" always choose poly when given the choice. My preference comes from cars where I want to increase the road feel and handling characteristics, so that's why I choose poly. You may feel differently about what you want from your vehicle and maybe poly is not the choice for you. I have poly in my XJ and I don't feel it is too harsh but I came from a corolla with sport springs and shocks which is much more harsh than the XJ with poly. I say if you like how your XJ is currently, then don't change it. Go for rubber and you'll forget you even thought about poly in the first place.