The Best Grease for Polyurethane Bushings

The Best Grease for Polyurethane Bushings
selection of polyurethane bushing grease

What is the Best Grease for Polyurethane Suspension Bushings?

Whether it’s a rock crawler, weekend track machine, or a daily driver that can take corners like it’s on rails, polyurethane bushings are great for performance and longevity, but they do require some infrequent maintenance to keep them quiet and in perfect working order. This can be done in your own garage or by the shop but one of the first decisions you have to make is, “What grease do I use?” The folks at DST will attempt to answer that question below.

Table of Contents


What Grease Should I Use For Polyurethane Bushings?

This is one of the first questions you need to answer and it can be a little confusing. Everyone has an opinion and there are several lubricant options, and honestly, any of them will “work” in the sense that all grease will lubricate a polyurethane bushing in some respect. That said, not all grease is created equal and when it comes to poly bushings you want two basic things: high adhesion (stickiness) and low coefficient of friction (reduced friction). Since the grease on these bushings is not in a sealed system it can be squeezed, melted, or washed out given the right circumstances so choosing the right grease is important. We will show you some of the best options when it comes to lubricant for polyurethane.

Silicone vs Lithium

As the two most common types of lubricants for polyurethane bushings we will take a look at what makes them tick.

silicone lubricant with ptfe

Silicone Based Lubricant

Silicone lubricant is very tacky and sticks to just about everything, from polyurethane, to zinc coated sleeves, to bare skin. This is the main reason many poly bushing manufacturers use a silicone base in their grease. A common additive to that base is PTFE (polytetrafluoroethylene) since it lowers friction and is completely waterproof, both things you want in a lubricant. PTFE does not mix well with oil, or any other liquid, but silicone grease seems to hold it well and the result is a sticky, slippery combination that keeps polyurethane bushings well lubricated and won’t wear or wash off.

lithium grease with moly

Lithium Based Grease

Lithium based grease adheres to metal very well, has a high heat tolerance, and is water resistant making it another possibility for use with polyurethane bushings. These lubricating agents are basically oil mixed with lithium soap, usually with several additives. One of the additives commonly used in lithium grease is Moly (Molybdenum Disulfide) which is actually a common additive to PTFE compounds. Lithium grease is usually thinner and it isn’t quite as tacky as silicone grease. Some manufacturers actually advise against using lithium based grease because they claim it can dry polyurethane out having adverse affects on your bushings.


Manufacturer Grease

Most aftermarket bushing manufacturers provide their own special blend of grease for their bushings and many include this in the box with the part. We here at DST suggest that you use the manufacturer’s grease since they are often formulated to work with the specs of that particular blend of polyurethane. If the manufacturer offers grease then this is likely going to be your best option since they have an interest in making sure the bushings you bought function quietly and correctly. You can purchase more of this grease separately when maintenance time comes around.

Prothane: Super Grease

prothane super grease polyurethane lubricant

  • Silicone Based with PTFE Additive

Energy Suspension: Formula 5

energy suspension formula 5 bushing grease

  • Silicone Based with PTFE Additive

SuperPro: WPGrease

superpro wp grease for polyurethane bushings

  • Silicone Based with PTFE Additive

Daystar: Lubrathane

daystar lubrathane polyurethane bushing lubricant

  • Silicone Based with PTFE Additive

WhiteLine: High Performance Bushing Lube

whiteline high performance polyurethane bushing lubricant

  • Lithium Based with Moly Additive

Other Suitable Lubricants

marine grease

Marine Grease

This style of grease is usually a lithium based grease that has many things in common with the manufacturer grease such as water repellent properties and tackiness. All the things that make this grease good for it’s designed purpose of handling applications around water also make it a good candidate for polyurethane bushing grease. That said, this grease is usually thinner than the manufacturer’s silicone based lubricant and isn’t designed for poly bushings so some of the additives could have adverse effects on your bushings.


heavy duty grease

Heavy Duty Grease

This is grease that is meant for heavy equipment and is very resistant cold, heat, and the elements. It is usually a lithium based grease with additives that make it tougher and more tacky so when it’s put under extreme pressure it stays put, but it is designed for more of a metal on metal application. This is an option if for some reason you can’t get more of the manufacturer’s grease, but I don’t know if you could call it a “good” one.


Not So Suitable Lubricants

80w gear oil

Gear Oil

Even quality 80W gear oil is not going to stick to your polyurethane bushings for very long. It works great in a closed system like heavy duty gear boxes where metal on metal parts are creating enormous amounts of friction and heat, but polyurethane bushings are not sealed and when your suspension travels whatever lubricant is between the bushing and the metal is going to be exposed to the elements. Gear oil has amazing lubrication properties, it just doesn’t have a chance to shine in the case of poly suspension bushings.


spray grease

Spray Lubricant

This is commonly used as a quick fix for squeaky bushings, but it has such a short effective lifespan that if you plan on it being a long-term solution just buy a case at Costco and keep it in the trunk. Whatever the brand, whatever the components, a spray lubricant is a poor substitute for the manufacturer’s silicone grease or even one of the other options.


used motor oil

Used Motor Oil From A Bucket Inside The Barn

Don’t. Just… don’t.


Testing the Grease

Time to put on our lab coats and safety goggles and see what this grease can do.

The Oven Test

bushing grease heat test

Just Like Mother Used To Make

Again, the upper limit heat range of this grease (some as high as 550 degrees) is not an every day occurrence but it’s nice to be able to see with your own eyes how the grease is affected by heat. So we applied the same manufacturer grease to those poly bushings, popped them into the DST cookie maker, and slowly turned up the heat. The bushing manufacturer advised against heating the bushing above 200 degrees for long so we set the heat and waited 5 hours. Here are the results.

Results

Yeah, nothing changed besides the fact that we had to air out the room afterwards. These lubricants can withstand a LOT of heat, in most cases more than the bushings themselves. If you use one of these lubricants and notice that it is dripping from one of your bushings then you may want to call the fire department to come put out your vehicle.


The Minor Adhesion Test

As we said before, this grease needs to be very sticky and what better way to test this than trying to wipe it off. If you’ve had any dealings with the manufacturer’s silicone based grease then you know that if you don’t wear gloves it will be with you for a while. This is what you want from your bushing grease so we’ll take a look at the difference between the manufacturer’s silicone grease and a marine grade lithium grease when you just try to wipe them away with a shop towel.

Manufacturer Grease

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Click for Larger Image

Marine Lithium Grease

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Results

Granted, the force applied to each bushing was probably a few pounds per square inch different, but you can see in this general demonstration that the manufacturer’s silicone grease clings to the bushing much better than the lithium grease. Even though some of the manufacturer grease can be wiped away there is still a layer hanging on to the bushing and removing it completely is very difficult.

If this test didn’t satisify you then you’re going to love the next one.


The Major Adhesion Test (The Big Guns)

Now while your grease is not going to be directly hit with a powerwasher, pressure and water are some common trials that the grease coating on your bushings will go through. Since DST is still debating the necessity of constructing a state of the art laboratory, we improvised a stand, took each of the manufacturer’s lubricants, a Moly Lithium Marine grease, a Moly Polyurea Heavy Duty grease, and 80W motor oil and plastered it on 8 identical polyurethane bushings. We powerwashed the bushings at a distance of 12 inches then again at 6 inches for about 4 seconds. These are the results.

*DISCLAIMER: This test does not reflect the actual use of these products. We merely wanted to test the adhesion to polyurethane properties of the different lubricants in extreme conditions. Some of this grease is designed to adhere to metal better than polyurethane. No, this is not a sterile, precise laboratory test. Yes, DST’s patent-pending stand is made of wooden pallets and deck screws.

12 Inch Range, 4 Seconds

6 Inch Range, 4 Seconds

Prothane: Super Grease

applied grease

Applied Grease

12 inch grease wash test

12 Inch Power Wash

6 inch grease wash test

6 Inch Power Wash

Energy Suspension: Formula 5

applied grease

Applied Grease

12 inch grease wash test

12 Inch Power Wash

6 inch grease wash test

6 Inch Power Wash

SuperPro: WPGrease

applied grease

Applied Grease

12 inch grease wash test

12 Inch Power Wash

6 inch grease wash test

6 Inch Power Wash

Daystar: Lubrathane

applied grease

Applied Grease

12 inch grease wash test

12 Inch Power Wash

6 inch grease wash test

6 Inch Power Wash

applied grease

Applied Grease

12 inch grease wash test

12 Inch Power Wash

6 inch grease wash test

6 Inch Power Wash

Marine Grade Lithium Grease

applied grease

Applied Grease

12 inch grease wash test

12 Inch Power Wash

6 inch grease wash test

6 Inch Power Wash

HD Polyurea Moly Grease

applied grease

Applied Grease

12 inch grease wash test

12 Inch Power Wash

6 inch grease wash test

6 Inch Power Wash

80W Oil

applied oil

Applied Oil

12 inch grease wash test

12 Inch Power Wash

6 inch grease wash test

6 Inch Power Wash

Results

It’s pretty clear from the pictures that the manufacturer’s silicone based grease held up the best.

All of the lubricants besides the HD Polyurea and 80W oil were still in place after the 12 inch powerwash. Prothane, Energy Suspension, and Daystar weathered the 6 inch powerwashing noticeably better than all the other lubricants. SuperPro started to give a little during the 6 inch wash, but performed better than Whiteline (the only lithium based manufacturer grease) which almost completely blew away. The Marine grease held steady with Whiteline while the HD and Oil were completely gone.


Consequences of Alternate Grease

bushing color change

The Final Reason

We left the grease on the bushings overnight then cleaned them off with bleach wipes in preparation for their next test and noticed that some of the bushings didn’t come off clean. The bushings that were greased with manufacturer grease looked the same as before the test but the bushings that used the Marine lithium and HD polyurea grease were stained which could indicate some sort of chemical reaction.

After calling the manufacturer of these bushings they said that they strongly advise using the manufacturer supplied grease because some lithium based grease could actually cause the bushing to dry out over time and even crack.

If you were looking for a definitive reason to use the manufacturer’s grease it doesn’t get much more plain than that.


In Conclusion

There isn’t much that will degrade or otherwise harm polyurethane bushings, but enough friction on anything without the proper lubrication can damage it. While most lubricants will work for your polyurethane bushings the grease that the manufacturers supply is going to last the longest and allow the part to work correctly. If for some reason you don’t have access to the manufacturer grease then a silicone based lubricant with a PTFE additive is going to be the next best thing. Other than that there are many stop gap measures but for noiseless operation and the well being of the bushing you should apply the manufacturer’s grease upon installation and when you begin to hear squeaking or 5 years after install, whichever comes first.

So, what types of grease or lubricants have you used to successfully lubricate polyurethane bushings? Have you tried some type of lubricant that didn’t work very well? Please let us know in the comments section below.

From all of us at DST: Ride Smooth (and quiet), and Drive Hard.

26 thoughts on “The Best Grease for Polyurethane Bushings

    1. Hey Christian,

      We just tested the grease that we had on hand, but it looks like SuperLube has a silicone grease with a PTFE additive which fits the basic criteria of what we found to be good grease for polyurethane bushings. We can’t vouch for their grease personally but it’s probably better than used motor oil in a pinch. Most brands of poly bushings have their own grease that will come with the part (and we recommend using that) but a silicone PTFE grease is a good substitute.

      Thanks for the input Christian.

    2. I’ve soured a little on Super Lube, which I’ve used for poly bushings on and off for years. I think it’s just too thin and not as tacky as the bushing specific option. It works ok if you happen to have grease fittings and can use it in a grease gun easily. But it just doesn’t have the staying power otherwise.

      1. Yeah, the tackiness is a pretty important factor. Suspension travel puts bushings through a lot and you want that grease to stick around and keep the friction low.

        Thanks for the insight David.

    1. Hey Barrie,

      It looks like krazygrease is petroleum based and meant for more of a metal-on-metal application like ball joints or tie rod ends. A silicone based grease is almost invariably going to stay on the bushing longer through more circumstances. Petroleum based grease might “work” for polyurethane bushings but the grease that the manufacturers supply is specifically made for poly bushings, so we suggest using that for longevity and proper operation of the bushing.

      Thanks for the comment Barrie.

  1. Many years ago I installed Dick Guldstrand poly bushings in the front control arms of my 1970 Camaro. The upper bushings were a softer red and the lower bushings were a very hard dark grey color. At the time, they recommended using moly as a lubricant as it is a good extreme pressure lubricant. That did not work out well and they squeaked miserably. I finally removed the bushings and found that the moly had plated the bushings with a shiny dark silver coating. I agree that using the manufacturers lubricant such as the Energy Suspension lubricant is the way to go. I have a tub of that and it is very sticky. However, I wonder how they perform under extreme pressures?

    1. Hey Mark,

      We totally agree with you about using the manufacturer’s bushing lubricant. I spoke with the folks at Energy Suspension about the extreme pressure factor and they had some insights.

      First of all, the squeaking and other problems generally arise when the grease is simply gone. Some grease types are fine lubricants but do not have the staying power required to keep the bushings quiet and healthy. Energy Suspension’s Formula 5 silicone based grease with a PTFE additive will usually last for 5+ years and can lubricate with the best of ’em.

      Second, the use of the vehicle and style of the driver is going to have a lot of influence over a poly bushing’s grease retention. If you’re clocking in A LOT of time at the track and driving the heck out of your car then you might experience some squeaking (which is a sign that the bushings need grease) before the 5-6 year mark when most poly bushings typically could use some re-greasing. Likewise for offroading, extended submersion in water, or high frequency of extreme suspension travel.

      Lastly, the bushing style can have a significant impact on grease retention. Some manufacturers use grooves, knurling, cross-hatching, etc. to hold pockets of grease so that even when the bushing is really squeezed the grease won’t be pushed out.

      Thanks for the question Mark, hope this was helpful.

    1. Hey Brian,

      I would love to know where you got that information. Because of the proprietary nature of the formulas involved the manufacturers won’t say exactly what is in their grease. We have spoken with both Energy Suspension and Prothane about their grease and beyond saying that it is a silicone based grease with a PTFE additive, it’s proprietary. Here is some more details about Formula 5 Prelube if you’re so inclined.

      All of that to say, yeah, they’re very similar. Whether or not they are exactly the same…

      The point here is that you’re better off with the manufacturer’s grease (which most manufacturers include in their bushing kits) than with a different lubricating option.

      Thanks for the input, Brian.

  2. Hey – Good work and thanks… I have been told, and found that, using some “grease” harms the bushings. Now, over my time at university, I spent a bit of effort creating moulds and pouring my own bushings to suit my own applications. After all that work no way would I put pure molybdenum disulfide (moly) “moly” on them. No freakin way, full stop. EVER. Surprised me that one of your test greases had “moly” added to the lithium formula to be honest. PTFE for the win here. Hell, even stick a pure nylon washer on the end if you are experiencing metal on metal problems. But that is truly getting off topic.

    Like you say, chemical reactions can (and do) occur. The very fact you noticed them within 24 hours shows what could (and does) happen over months or years.

    Also, just for reference, chemical nature of the resins means that when spraying a vehicle near the bushings you should be very careful to hide the bushings behind a plastic bag wrapped around the areas. The solvents in the acrylic paint can (and will) make a nice mess of the chemical structure of the bush.

    Anyways, thanks for the write up. I hope it puts some people “right” on what to use. And may stop people thinking a certain bush manufacturer is producing garbage product and shooting their mouths off all over net stupid land about how their bushes fell apart.

    1. Hey Tony,

      We appreciate the compliment! It’s always cool to see a poly DIYer. Our intent with the write up was to try and show people that polyurethane bushings don’t have to be noisy and will last a long time if properly lubricated at install.

      It’s hard to say for sure what the long term effects of different grease on polyurethane would be, but the color change in such a short amount of time seemed pretty significant. We don’t have the exact formula of the grease that contained the Moly additive, and we don’t have first-hand knowledge of how it performs (anyone?), but bottom line: silicone with PTFE is the standard for polyurethane grease.

      Thanks for the tip about painting around poly bushings. They stand up really well against wear and the elements, but they aren’t impervious. Using the “right” lubricant goes a long way toward making them go a long way.

      Have a good one Tony.

  3. PS – Out of idle curiosity, in a sealed unit (eg – stuff the pressure wash test) has anyone looked into a graphite powder. In theory, could be okay. In reality, most likely complicated waste of time.

    🙂

    1. Well Tony, when we say sealed unit in the post we’re referring to other suspension components like ball joints or tie-rod ends that have a sealed bearing where different types of grease can be used since they don’t have to worry about adhesion in the face of the elements like poly bushings do.

      We talked with techs at Energy Suspension and Prothane about graphite powder on poly bushings and they gave similar answers: It might work, but you’re better off with the manufacturer supplied grease. The same thing has been said of Teflon tape, spray lube, and several other options. All that said, it might work great. Prothane’s black poly bushings do have a slight graphite impregnation so it doesn’t appear that it would harm the bushings, but whether or not it’s better than the grease… the manufacturers say go with the grease.

      If anyone has first-hand experience with graphite powder on poly bushings please share!

      Thanks for the curiosity Tony.

    1. Hey Rahul,

      The small 3oz tubes that come with most kits should be enough to handle several bushings. You just want to cover the surface that will be in contact with the sleeve with a thin layer and while you’re at it, give the sleeve a good coating too. You can put as much as you want, just be sure to wipe away any excess to prevent debris from getting caught in the grease.

      Hope this helps!

  4. Hello, first of all, it’s a very good post.

    I would like to know if i use some silicone grease spray,if is good or not?

    Thank to you,

    1. Hey Denis,

      It might depend on the spray, but as a general rule spray lubricant is not going to stick to your bushings very long. Especially if a lot of water or mud is being thrown around under your vehicle. If you’re coming up on your 5 year bushing maintenance mark and just trying to quiet your ride down until you have the time to tackle that job then a spray will last you a while, but it’s really just a band-aid.

      Hope this helps.

  5. I’m contemplating new Daystar polyurethane bushings for my 1987 Jeep leaf springs. They obviously recommend their own proprietary lube. I have settled on an NLG1 GC-LB (wheel bearing & chassis) lithium red grease as my go-to chassis lube as it was recommended by my drive shaft manufacturer and it works great for all the front end steering parts too. I would prefer to only have to keep one grease gun and one type of grease. If I shoot NLG1 red into my grease-zerk polyurethane spring bushings are they going to disintegrate with time or otherwise fail? I’m assuming that if I grease these bushings whenever I grease the rest of the chassis I don’t need to worry about running them dry. The previous rubber bushings have been run dry for close to 30 years and are in surprisingly good shape considering.

    Thanks for all your work on this post. Great info.

    1. Hey Jason,

      The short answer to your question is maybe.

      We can’t say for certain that disintegration or failure would take place based on the type of grease you use. That said, In our talks with several poly bushing manufacturers, they’ve all touted their own grease as best, and all (but one) had one thing in common; they’re silicone based. This has a lot to do with the adhesion of the grease to the polyurethane surface, though some of the manufacturers have warned that lithium-based lubes might cause the bushings to dry out over time.

      Another concern is that some of the additives in grease that is designed for machine application (chassis and bearing grease) could have, as yet unknown, effects on poly bushings. During our tests, we did witness color change in the bushings that were coated with multi-purpose grease that could be a symptom of a chemical reaction of some kind. Testing this would require some long-term observation and the sources we spoke with were not able to provide any hard facts regarding this.

      I would imagine with frequent maintenance you would be ok using the grease you mentioned, but I can’t make any guarantees. With a Jeep I would probably ask, “what are you planning on doing with it?” If you’ve got a snorkel on your exhaust, and plan on using it regularly, you might reconsider going for another grease gun with a silicone based grease. If you’re staying above sea-level and not climbing rocks or burying the axles in mud you might be ok with a lithium chassis and bearing grease. Either way, your safest option for longevity is the manufacturer’s grease or a silicone based grease with a PTFE additive.

      Does anybody have any long-term experience with lithium grease on poly bushings?

      Hope this was helpful, Jason. And if you do go with the chassis grease please check back with us later and let us know how it’s working out.

      1. Josh, thanks for the detailed reply. I replaced my leaf springs today and was happy to see that decades ago someone had installed Daystar polyurethane bushings for me, however, without grease zerks. These bushings have been totally dry for probably 20+ years and have not squeaked a bit. I had to shift them over to my new springs as I hadn’t planned ahead for new bushings, but these were in surprisingly good shape. I don’t have a website but if you want pics of 20+ year old unlubed poly bushings I have them. Since no one stocks silicone grease locally I had to put on a thin film of red lithium grease to re-install them, but I will get some silicone grease once I get some new shackles with zerks.

        20 year old daystar leaf spring bushings

        1. Thanks again Jason,

          Daystar makes an awesome product so I’m not surprised to hear that your leaf spring bushings are still in good shape. I am a little surprised that they’ve been in there for two decades with no additional lube and haven’t made a peep! It stands as a testament to the excellent quality of the product since most manufacturers will tell you to regrease those bushings every 5 years. Shameless plug: We do sell the several manufacturers’ poly bushing grease including Daystar and Prothane which comes in a 14oz grease gun sized tube.

          We would love to see those pictures! You can email them to [email protected] and we’ll add them to the bottom of your comment. Thanks again, Jason, and good luck with the new leaf springs.

    1. Hey Steve,

      Both dieletic and some suspension grease use silicone oil but the thickeners and other additives could be different.

      The term “silicone grease” can be kind of deceptive. Grease is oil mixed with thickening additives and a common base is silicone oil or petroleum. Since the exact formulas for these greases are proprietary it’s hard to say how they might be different. Dielectic grease is not supposed to contain elements that would promote arcing in electrical applications, but I can’t speak for poly bushing grease having the same property.

      In any case, it’s probably best to use the individual greases for their intended purposes. In a pinch, if you have dielectic grease that’s silicone based with a PTFE additive then you would probably be ok putting it on polyurethane bushings, but there could be unintended effects because of other additives. I wouldn’t try using a poly bushing grease for electrical purposes though.

      Hope this helps, Steve.

  6. Well appears that it is more about composition than brand.. I would guess almost any full synthetic with PTFE is going to rate just fine..

    I am also drilling and fitting grease zirks.. Just seems a nice little flush every now and then might save a bunch of work later…

    1. Hey RandyO,

      Yes, you’re right. Grease with a silicone base and a PTFE additive should do the trick. The only potential problems could be the effects of other additives in grease not designed for poly bushings. As for Zerk fittings, we’re also partial to them. It is good to refresh your old grease from time to time to keep everything working properly, especially if you are in mud, slush, or water on a regular basis.

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