Best Grease for U Joints – 10 Options Reviewed

I’ve spent countless hours wrenching on trucks and ATVs, and let me tell you, keeping your U-joints properly greased is crucial. A neglected U-joint can lead to expensive repairs, and trust me, that’s a headache you want to avoid. This guide dives into ten different greases, offering a detailed comparison to help you choose the best grease for your U-joints based on your needs and budget. We’ll cover everything from high-performance synthetic options to more affordable choices, highlighting the pros and cons of each.

IMAGE	PRODUCT NAME	AMAZON LINK
	Polaris Genuine OEM 14 oz. U-Joint Grease All Terrain for…	View on Amazon
	Moly-Fortified Synthetic Grease – 2 Pack (14.1 OZ Each) |…	View on Amazon
	Royal Purple Ultra-Performance Synthetic Grease, 14.5 oz…	View on Amazon
	OKYOUK Grease Gun Accessory Set,Grease Injector Needle…	View on Amazon
	Polaris U-Joint Grease, for Specific RZR, Ranger and…	View on Amazon
	Sta-Lube Constant Velocity (CV) Joint Grease SL3174-4 Wt….	View on Amazon
	Rockwell 2.5 Ton Axle Shaft U-Joint with Grease Fitting	View on Amazon
	Innovative Products of America Grease Joint Rejuvenator®…	View on Amazon
	The ROP Shop (Pack of 2) Cross & Bearing U-Joint…	View on Amazon
	Grease Buster® – The Original, Made in The USA by…	View on Amazon

1. Polaris Genuine OEM 14 oz. U-Joint Grease All Terrain for…

This is the grease Polaris recommends for their own machines, so you know it’s designed to withstand some serious abuse. It’s specifically formulated for high-shock applications, and the molybdenum additive helps cushion those impacts. I found it to be exceptionally water-resistant, a big plus for those of us who regularly tackle muddy trails.

• Extremely water-resistant
• Molybdenum additive for shock absorption
• High shear stability
• Superior adhesion
• Recommended for Polaris vehicles

Pros:
– Excellent water resistance
– Designed for high-impact situations
– Performs well in extreme conditions

Cons:
– Can be more expensive than other options
– May not be necessary for less demanding applications

User Feedback Summary: Generally positive reviews, with users praising its durability and performance in harsh environments.

2. Moly-Fortified Synthetic Grease – 2 Pack (14.1 OZ Each) |…

This moly-fortified synthetic grease is a solid all-around performer. The synthetic base offers excellent high-temperature stability, and the molybdenum helps prevent wear and tear. I appreciated the two-pack, great value for the money.

• Moly-fortified synthetic formula
• High-temperature performance
• Protects U-joints, bearings, and suspension
• Water and washout resistant
• Multi-pack available

Pros:
– Good value for money (comes in a pack)
– High-temperature stability
– Effective protection against wear

Cons:
– Might not be as water-resistant as some specialized greases

User Feedback Summary: Users report good performance and longevity, with many appreciating the value of the two-pack.

3. Royal Purple Ultra-Performance Synthetic Grease, 14.5 oz…

Royal Purple is a name synonymous with high-performance lubricants, and this grease lives up to the reputation. It’s exceptionally smooth, offering excellent protection and reducing friction. The high operating temperature is a significant advantage.

• Synthetic formulation
• Excellent extreme pressure capabilities
• Outstanding water resistance
• High operating temperature (500°F)
• Versatile applications

Pros:
– Superior performance
– High-temperature stability
– Excellent water resistance

Cons:
– Premium price point

User Feedback Summary: Users consistently praise its performance and smoothness, although the price is often noted as a drawback.

4. OKYOUK Grease Gun Accessory Set,Grease Injector Needle…

This isn’t grease itself, but a crucial tool. A good grease gun is essential for proper U-joint lubrication. This kit offers a range of adapters, making it compatible with various vehicles.

• Comprehensive grease gun kit (8 pieces)
• Durable, rust-resistant construction
• Universal compatibility
• Easy, leak-free connection
• Portable organization

Pros:
– Versatile set for various applications
– Durable and reliable tools

Cons:
– Not a grease itself, but a supporting tool

User Feedback Summary: Users generally find this kit useful and durable, but some might find the need for only few adapters.

5. Polaris U-Joint Grease, for Specific RZR, Ranger and…

Another Polaris OEM option, this one is formulated specifically for their U-joints. Similar to the previous Polaris grease, it provides excellent protection and longevity. However, it’s crucial to verify compatibility with your specific machine.

• Heavy-duty lubricant with molybdenum disulfide
• Designed for Polaris ATVs
• Extreme protection under harsh conditions
• Versatile use
• OEM quality

Pros:
– Designed for specific Polaris models
– Excellent protection and longevity

Cons:
– Limited compatibility – only for certain Polaris models
– Can be pricey

User Feedback Summary: Positive feedback from Polaris owners, but those with other brands should check compatibility first.

6. Sta-Lube Constant Velocity (CV) Joint Grease SL3174-4 Wt….

While designed for CV joints, this grease also works well in some U-joint applications. The molybdenum disulfide and polymer additives provide good protection against wear and tear.

• Lithium-based grease with molybdenum disulfide and polymers
• Designed for CV joints, suitable for some U-joints
• Excellent performance under stress and shock loads
• Suitable for domestic and import CV joints

Pros:
– Good protection against wear
– Relatively affordable

Cons:
– Primarily intended for CV joints, may not be ideal for all U-joint types
– Smaller tube size

User Feedback Summary: Users report it works well for CV joints and some U-joints, but some may prefer a more specialized grease for U-joints.

7. Rockwell 2.5 Ton Axle Shaft U-Joint with Grease Fitting

This isn’t a grease, but a U-joint itself with a pre-installed grease fitting. If you need to replace a U-joint, this is a good heavy-duty option. The grease fitting makes lubrication easy.

• Heavy-duty construction
• Grease fitting for easy lubrication
• Reliable performance

Pros:
– Durable and reliable U-joint
– Convenient grease fitting

Cons:
– Not a grease, but a U-joint replacement part

User Feedback Summary: Positive reviews for its durability and easy lubrication, but remember, it’s a replacement part, not a grease.

8. Innovative Products of America Grease Joint Rejuvenator®…

This product isn’t a grease but a cleaner and rejuvenator. If your U-joint fittings are clogged, this can help clear them out before you apply fresh grease.

• Cleans clogged grease joints
• Replenishes old grease
• Easy to use

Pros:
– Helps to clean and restore old joints
– Useful for maintaining existing grease joints

Cons:
– Not a grease itself; requires a grease to follow up

User Feedback Summary: Users who had clogged fittings found this helpful, but it’s not a replacement for regular greasing.

9. The ROP Shop (Pack of 2) Cross & Bearing U-Joint…

Similar to the Rockwell option, this is a replacement U-joint, not grease. It comes with grease fittings, though, making future lubrication easier. Confirm compatibility with your specific application.

• Pack of 2 U-joint assemblies
• Includes grease zerk fittings
• For specific Volvo Penta applications

Pros:
– Replacement part with grease fittings for easy lubrication

Cons:
– Needs compatibility check before purchase
– Not a grease, but a part replacement

User Feedback Summary: Good for those needing to replace their U-joints, but compatibility is key.

10. Grease Buster® – The Original, Made in The USA by…

Another cleaning tool, this one uses hydraulic pressure to flush out old grease. It’s helpful for really stubborn, clogged fittings.

• Cleans and flushes out old grease
• Uses penetrating oil and hydraulic pressure
• Reduces downtime

Pros:
– Effective for cleaning severely clogged fittings
– Saves time and money compared to bearing replacement

Cons:
– Requires separate purchase of hose extension and pneumatic piston
– Not a grease itself

User Feedback Summary: Helpful for those with extremely clogged fittings but needs added equipment

Practical Buying Advice:

The best grease for your U-joints depends on several factors: your budget, the type of vehicle or equipment you’re using, and the operating conditions. For high-performance vehicles or those used in extreme conditions (off-roading, heavy hauling), a high-quality synthetic grease with molybdenum disulfide is recommended. For less demanding applications, a more affordable lithium-based grease might suffice. Always check your owner’s manual for specific grease recommendations. Don’t forget a good grease gun!

FAQ:

Q: How often should I grease my U-joints?
A: This depends on usage, but generally every 50-100 hours of operation or every 3-6 months is a good guideline. Check your owner’s manual for specific recommendations.

Q: What are the signs of a poorly greased U-joint?
A: Clunking or clicking noises, excessive play or movement in the joint, and difficulty turning the driveshaft are all indicators of insufficient lubrication.

Q: Can I use any grease in my U-joints?
A: No. Using the wrong type of grease can lead to premature wear and failure. Check your owner’s manual for recommendations or choose a grease designed for high-shock applications.

Q: What is molybdenum disulfide (MoS2), and why is it important in U-joint grease?
A: MoS2 is a solid lubricant that provides excellent protection against wear and tear, particularly under high-pressure conditions. It’s a common additive in high-performance U-joint greases.

Q: What’s the difference between synthetic and lithium-based grease?
A: Synthetic greases generally offer better performance at high temperatures, have better water resistance, and last longer than lithium-based greases. However, they often come at a higher price.

Q: How do I properly grease a U-joint?
A: First, locate the grease fitting (zerk fitting). Attach your grease gun to the fitting and pump grease into the joint until fresh grease starts to come out of the seals. Wipe off any excess grease. Refer to your owner’s manual for detailed instructions.

Remember, regular lubrication is key to extending the life of your U-joints and avoiding costly repairs. Choose the grease that best suits your needs and budget, and don’t forget the importance of proper greasing techniques.