Everyone has an opinion about what type of grease should get used for their polyurethane bushings.
That means you can search online for this information and get five different results from five websites. How do you know which author to trust?
It is true that several lubricant options are available for today’s polyurethane bushings. All of them work in the traditional sense that the grease reduces the friction that can develop.
Some products are not created equally. Since the grease isn’t in a sealed system, it can get washed, melted, or squeezed away under the right conditions. That’s why choosing the best product is essential for the long-term health of the polyurethane bushings.
The Best Grease for Polyurethane Bushings
A silicone-based lubricant is the best grease for polyurethane bushings on today’s vehicles. This product delivers what is needed for longevity and performance, although the maintenance is usually infrequent. Most people can do their work in their shop or garage once they have the grease.
Why is a silicone-based lubricant the best option for polyurethane bushings?
It has a tacky feeling to its surface, allowing the grease to stick to almost anything. That includes the poly bushings, the sleeves, and even your hands.
Most manufacturers with a silicone-based product add polytetrafluoroethylene (PTFE) to their grease to lower the friction point. The additive also creates a waterproof effect that is less likely to work its way out after performing this maintenance task.
PTFE creates a secondary benefit for the grease because it doesn’t mix well with oils or liquids. It does hold with the silicone-based lubricant so that the polyurethane bushings and their sleeves receive support, making it a robust combination that stays put under most conditions.
◼️ What Alternatives Are There for My Polyurethane Bushings?
If you don’t want to use a silicone-based lubricant for your polyurethane bushings (or the manufacturer recommends against it), the next most popular choice is a lithium-based grease.
Since the lithium makes the grease have a higher heat tolerance, it can consistently adhere to the metal while delivering a water-resistant coating.
This product is essentially a mixture of oil and lithium soap that serves as the lubricant for your polyurethane bushings. Several additives are also part of the ingredient profile, with the most common being molybdenum disulfide, or “Moly.”
You can find Moly in most PTFE compounds because of the benefits it offers. When you apply lithium-based grease to your polyurethane bushings, you’ll notice that it tends to be thinner and less sticky than silicone.
It doesn’t typically last for as long, but it can still be a reliable choice for anyone who gets behind the wheel of their vehicle daily.
What About Manufacturer Blends for My Polyurethane Bushings?
If you need to add some grease to your polyurethane bushings, you’ll discover that most aftermarket manufacturers create a special lubricant blend for their products.
When you purchase the poly bushings, you’ll probably get the grease for them in the same box if the manufacturer offers it.
It’s almost always the best practice to use the lubricant sent by the manufacturer instead of a third-party product to ensure you get the intended result. The goal of that product is to help the polyurethane bushings perform correctly and quietly, and you can always purchase more of it when it is time to complete your next maintenance check.
Here are the products you’ll receive when you purchase poly bushings from some of today’s best brands.
| Prothane Bushings: | You’ll receive a silicon-based lubricant with a PTFE additive in the box. |
| Energy Suspension Bushings: | You’ll receive a silicon-based lubricant with a PTFE additive in the box. |
| SuperPro Bushings: | You’ll receive a silicon-based lubricant with a PTFE additive in the box. |
| Daystar Bushings: | You’ll receive a silicon-based lubricant with a PTFE additive in the box. |
| WhiteLine Bushings: | You’ll receive a lithium-based lubricant with a Moly additive in the box. |
Suppose you don’t receive a manufacturer’s product with your new polyurethane bushings and don’t have access to a silicone- or a lithium-based product. In that case, a few alternatives are suitable to use when you need to get the maintenance work finished.
Marine grease is usually a lithium-based product that delivers a similar result to what you’d get from most manufacturers. There’s enough tackiness and water-repellant qualities to the lubricant that it’ll serve its purpose well.
It is usually thinner than other products, so you’ll need to check on everything periodically to ensure it continues functioning as intended.
Heavy-duty grease is another alternative to consider for your polyurethane bushings. It is usually meant for heavy equipment, which means it resists temperature changes exceptionally well.
It can also handle the elements you’ll encounter outside. The additives to this lithium-based product help it get tackier under pressure, ensuring that the results you need can develop.
What Lubricant Options Should I Avoid with My Polyurethane Bushings?
If you don’t have any grease or lubricant stored in your garage or shop that meets the specifications noted above, it might be tempting to use an alternative product that provides a similar result in other situations.
When the item isn’t intended for use with polyurethane bushings, you should avoid applying it under any circumstance.
Here are the lubricant options you’ll want to avoid when you don’t have silicone or lithium grease to use for your poly bushings.
1. Spray Lubricants
When you have squeaky bushings, a spray lubricant provides a quick fix. The problem with this option is that the effective lifespan is relatively short. It won’t create a long-term maintenance benefit. You’d be buying cases of the stuff to keep in your vehicle so that you can spray it on almost every day.
The two most popular brands that people use as a grease substitute for their polyurethane bushings are Liquid Wrench and WD-40. Although these sprays have usefulness in their own right, they’re not appropriate for this particular job.
2. Motor Oil
Although this product delivers a lubricating factor to your polyurethane bushings, it doesn’t have the tackiness needs to offer a long-term maintenance benefit. Motor oil works better when there’s a closed environment where metal-on-metal parts create heat and friction.
Since poly bushings aren’t sealed, the motor oil will drip out and force you to address the lubrication issues again relatively quickly.
Some people might say that a heavy-weight motor oil has some sticky qualities to it, but not even an 80W product can come close to the benefits of a lithium-based grease, much less one made with silicone.
3. Food-Grade Oil
You can find stickier oils when shopping at the grocery store if you’re looking for a grease alternative for your polyurethane bushings. The problem with food-grade items is that they have a lower heat point. There can be enough friction in this environment that the liquid could start smoking or catch on fire.
Even cooking oil meant for biodiesel needs to get processed appropriately before it becomes a usable product.
Food-grade products also contain an ingredient profile that can corrode or degrade the polyurethane bushings. You can find preservatives, sugar, salt, and other chemicals in there that can clog things up or hamper performance.
Since it is an oil, this option would also leak out of the unsealed area quickly, forcing you to reapply materials constantly.
4. Used Oil or Grease
If you have leftover oil or grease from another project, it might be tempting to use it for your polyurethane bushings. Anything that isn’t fresh creates a higher risk of contamination that could interfere with how everything operates.
Even if you have leftover silicone-based grease from another maintenance need, it should not get used for your poly bushings unless it has never come out of its tube or packaging.
Consequences of Using an Alternative Grease
The reason you want to avoid an alternative grease or lubricant for your polyurethane bushings is that residues get left behind.
Your bushings exist in a harsh environment. They need support to function correctly, and that isn’t always possible when using products meant for other purposes.
That’s why using the manufacturer’s grease for the polyurethane bushings is always the first and best choice. Even if you need to wipe them clean to start over, you’ll get a positive result. If you’re using something like a marine lithium lubricant or HD polyurea, materials can get left behind on the product.
Although you want some stickiness, the lubricant shouldn’t act like a cholesterol deposit in an artery. You want it to be a free-flowing environment that offers friction elimination.
When you look at the warning labels on most of today’s polyurethane bushings, you’ll see that many of them strongly advise against using lithium-based products. It can cause the materials to become overly dry and crack, resulting in a more complicated and costly repair.
If you need a reason to invest in or use manufacturer’s grease for your polyurethane bushings, that’s it.
How to Grease Polyurethane Bushings
Although every process is slightly different, you can follow these steps after securing the lubricant or grease you need to support how your polyurethane bushings function.
If they aren’t maintained properly, they can make noises that become problematic in some settings. It can also make things harder to control if they create issues within the suspension.
Here are the general steps to follow if you need to grease your polyurethane bushings today. Please remember that any manufacturer’s instructions should supersede what you find below.
- Install the dry polyurethane bushings into the control arm pivots from your vehicle.
- Once the bushings are installed in the control arm, apply a generous amount of silicone-based grease to the inner diameter of the product. The goal is to fill all the grooves entirely with this product.
- You’ll now add more grease to the outer diameter of the metal inner sleeves.
- Use the mallet to install the metal inner sleeve into the polyurethane bushing. If it doesn’t fit as expected, a smooth-jaw vise or an arbor press can also help you accomplish this step.
- Once the two items are together, use the excess grease and a small brush to lubricate the bushing hats where they make contact with the control arm pocket or the plated end washers.
- If you need to install zerk fittings, it might become necessary to clean out the top of the threaded hole with a sharp object to catch the NTP threads. Don’t try to tighten it to the bottom, as it only needs to be snug.
- Rotate the zerk until you create a fitting accessible for a grease gun.
Many of today’s greasing maintenance tasks are designed to let you work with the control arm remaining on the vehicle. If you decide to use that method instead of taking it off, you’ll need to loosen the bolt holding the polyurethane bushings together first.
That will open an area for the grease to expand when pumping it through the zerk. If you don’t loosen it, the lubricant won’t have anywhere to go. That will cause it to hydraulic and destroy the bushing.
If you see the polyurethane bushing begin to deform, stop what you are doing immediately. You’ll need to grab a small pick, push in the ball to the fitting, and release the pressure that exists within the environment.
With the bold still loose, keep pumping grease into the fitting until you see some excess product bleed out from between the plated end washing and the hat.
You’ll need to refer to the applicable torque specs from the factory settings to complete the job. After you’ve driven 500 miles, you’ll want to rec-check the hardware to ensure that nothing has loosened inappropriately.
Polyurethane vs. Rubber Bushings: Which Is Better?
You have two choices for your suspension when it is time to update your bushings. Although poly does an excellent job, some drivers might prefer rubber. The latter is what comes standard on most vehicles.
If you were happy with how your vehicle drove before it started shaking, rubber might be the way to go.
With polyurethane bushings, you’ll get a few advantages that start with the product’s durability. Since they don’t deteriorate or rot, they’ll often outlive the car.
Here are some of the other qualities to consider with polyurethane bushings.
| Ride Quality: | • Since polyurethane bushings are more rigid, they tend to produce a bumpier ride. • You’re compromising on some noise and vibration to get a more durable product. |
| Squeaking: | • Although some people think poly produces squeaks, they do not. • You just need to be proactive about checking on the lubricant to ensure the suspension functions as intended. |
| Price: | • You’ll find that polyurethane bushings tend to be cheaper than rubber or aluminum alternatives. |
| Feel: | • Poly bushings tend to make the vehicle feel like it is an extension of who you are behind the wheel. • Although some bumps might be more pronounced, it often lets drivers feel like they’re having more fun or building their skills. |
| Maintenance: | • Most poly bushings need to be greased about every three to five years. • Rubber ones don’t have that requirement, but they can also rot within the joint. |
| Installation: | • After you remove the older bushing, installing a new poly one is a straightforward experience. |
| Lifespan: | • Poly is more resistant to rust, heat, oil, and UV exposure. • They’re often covered with a comprehensive warranty so that you have options if a failure occurs. |
Although a switch to poly from rubber bushings changes how a vehicle drives, it’s often for the better.
In Conclusion: What Is the Best Grease for Polyurethane Bushings?
The best grease for polyurethane bushings is whatever the manufacturer sends in the box. If you don’t receive anything or run out and can’t secure more, a silicone-based lubricant is your next best choice. Only use a lithium product if there aren’t warnings against it on the bushings.
The lifespan of your suspension bushings is highly variable. It all depends on your environment, driving style, and the quality of the installed product. That’s why there isn’t a set interval for polyurethane bushing replacement in your maintenance schedule.
Mechanics recommend replacing the bushings when you start noticing some specific symptoms when you’re on the road.
- Excessive vibration or road noise in the vehicle.
- Steering that has an excessive lack of control or is unusually loose for the vehicle.
- Creaking or banging sounds that come from the fender.
- Rattling noises coming from the frame when navigating over rough terrain.
Although you can theoretically use almost any grease or lubricant for your polyurethane bushings, the only long-term solution is to use a silicone-based product. Everything else increases the risk of further damage occurring.
When you shop for a third-party product, you’ll see that “silicone paste” gets included with your search filter. That is not the same thing because it tends to be a synthetic that doesn’t have the same consistency.
You’ll also want to review the temperature rating for grease consistency to ensure that it meets your vehicle’s specs.
Giving your polyurethane bushings some grease can help your suspension work better and quieter, especially if you have an older vehicle. By taking appropriate steps today to manage this issue, you can stay behind the wheel for many more tomorrows.
