Nearly every moving part in your car has a bearing of some sort. When most people think of bearings, they think of big ball bearing assemblies like what you find on the front wheel hubs, but there are many different types of bearings, and how you maintain them varies by the style. Some bearings need no real maintenance at all, while others are much more sensitive to changes and have to be serviced regularly.
Low and No-Maintenance Bearings
While it may not seem like, the hinges on your vehicle are full of bearings, except that these are called bushings. All bushings are bearings, they just don’t have any moving parts inside them. Instead, these are sacrificial components designed to give up themselves rather than allow the hard parts to be broken down. When your door or trunk lid gets sloppy and won’t open or close easily, the culprit is typically worn out bushings, because they have done their job. You can read all about replacing this type of bearing here. Bushings are typically made of softer metals than the master component, bronze, brass, and aluminum are the most common.
Some hinge bushings are not replaceable, you have to replace the entire assembly. You can give these bushings some extra life by treating them with some fluid lubrication. There are many types of lubricants sold for these specific uses, such as WD-40 Original, but there are some specialty ones too, like WD-40 Specialist Dirt & Dust Resistant Dry Lube and dry graphite sprays like Slip-Plate. Dry graphite creates a barrier layer of slippery graphite, which does not get sticky or greasy, so the parts stay clean. Grit from dirt and dust accelerate the wear of bushings, so removing that from the equation is always good.
Common Service Bearings
There are a number of bearings on your vehicle that you service regularly without even realizing that you are servicing them. There are quite a few bearings, mostly of the bushing-type, that are serviced every time you change the oil. This is one of the main reasons that you have to constantly change your engine oil and oil filter. The bearings on your engine’s rotating assembly are the most fragile, they are made from a small base of steel which is covered by a thin aluminum layer. It does not take much heat to melt and wipe away the aluminum. These are called bi-metal bearings, and they are more durable than tri-metal bearings, which have a copper\lead layer in addition. Tri-metal bearings do not last as long as bi-metal bearings, though they are more forgiving in terms of garbage in the oil.
The reason that modern engines can last 300k miles is all thanks to the bi-metal bearings. If you don’t change your oil consistently and with good quality oil and filters, then you are simply allowing microscopic particles to eat away at the bearings that keep your engine spinning smoothly.
Adding an oil stabilizer, such as Lucas Oil Stabilizer, reduces friction by coating the bearings with a thick film. This does not add any stress to the oil pump, but provides a layer of protection from dry starts, which occur every time you start your engine after it has sat for an hour or more.
Don’t forget about the transmission either, which is full of bearings. While your transmission fluid is not regularly changed, it can be treated the same way with a conditioning additive.
Now we are getting into the big stuff, the bearings that you think about when you hear that word. Big chunky ball bearings and thin needle-bearings that need specific lubrication. These are found in several places on your vehicle, including each wheel hub/axle, inside the rear axle housing, and on the drive shaft.
Most people forget to service the wheel bearings, but they need to be protected with fresh grease about every 30k miles (12k for trailers). Many newer vehicles use sealed wheel bearings which are not serviceable, but don’t take that for granted. Servicing your wheel bearings is pretty simple, you can simply remove the dust cover and seal, remove the bearings, clean them well with brake cleaner, inspect for wear, and then re-pack the bearings with new grease. We like to use a bearing packer, but you can pack them manually as well. Check out our article on grease for more information on selecting bearing grease. Don’t forget to buy a new seal, you won’t reuse the old one.
Other serviceable bearings include the U-joints on the drive shaft. These are actually 4-way bearings, and the grease inside them is what keeps them spinning. Each cap is filled with tiny cylinders called needle bearings. If you have ever had a U-joint break or drop a cap, you know what a pain in the rear these can be, they go everywhere. Similar to ball bearings, needle bearings roll between the inner and outer halves of the bearing, providing reduced friction for the components. As with all metal-to-metal contact, you have to have lubrication in there, otherwise, things get heated really fast. Spicer, one of the biggest U-joint manufacturers in the world, recommends servicing your U-joints every 5-15k miles, depending on the use. City vehicles every 5-8k miles, while vehicles that spend most of their time on the highway can go 10-15k. Some U-joints are sealed and are not serviceable, so they should be inspected every 25k miles.
The bearings in your vehicle serve an important purpose- to take the abuse so that your hard parts don’t have to. If you ignore the service intervals of your bearings, you will find out the hard way just how much that can cost. Do your pocketbook a favor and treat your bearings to some good old preventative maintenance, they will last longer for it.
Check out all the drivetrain parts available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on vehicle bearing maintenance, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.
Photo courtesy of Pixabay.
A life-long gearhead, Jefferson Bryant spends more time in the shop than anywhere else. His career began in the car audio industry as a shop manager, eventually working his way into a position at Rockford Fosgate as a product designer. In 2003, he began writing tech articles for magazines, and has been working as an automotive journalist ever since. His work has been featured in Car Craft, Hot Rod, Rod & Custom, Truckin’, Mopar Muscle, and many more. Jefferson has also written 4 books and produced countless videos. Jefferson operates Red Dirt Rodz, his personal garage studio, where all of his magazine articles and tech videos are produced.