Jump to content

  • Welcome to Auto Parts Forum

    Whether you are a veteran automotive parts guru or just someone looking for some quick auto parts advice, register today and start a new topic in our forum. Registration is free and you can even sign up with social network platforms such as Facebook, X, and LinkedIn. 

     

Understanding Steering Knuckles


Recommended Posts

The wheel bearings are the backbone of the vehicle suspension. They support the weight of the vehicle, help to keep the wheels in alignment and allow the wheels to rotate with as little friction as possible. But wheel bearings can’t do their job without a strong mounting point, and that’s the knuckle.

What Is the Knuckle?

The knuckle, also known as the spindle, is the suspension component that houses the wheel bearing, and the connection between the wheel and the suspension system. In the past, knuckles typically were made of steel, but today they’re more commonly made of aluminum or another lightweight alloy to save weight.

On the front of the vehicle, the knuckle will pivot on upper and lower pivot points as the driver turns the steering wheel, changing the direction the vehicle is traveling in. In the rear suspension, the knuckle won’t pivot, but instead will travel up and down. Any time you’re removing or replacing a wheel bearing, ball joint, tie-rod end or control arm, you’ll be working on a knuckle.

Since the wheel bearings and the knuckles work together, sometimes it will make more sense to replace them together. This type of assembly is referred to as a “loaded knuckle.” Why would a customer decide to install a loaded knuckle? In most cases, it comes down to one of two reasons: damage or time.

What Can Damage a Knuckle?

They can be damaged during a crash or a collision, or from violently striking a curb or a deep pothole. This type of damage can change the geometry of the suspension, causing a crooked steering wheel, wandering steering feel while travelling straight, or steering bind. If left alone long enough, it even can result in abnormal tire wear down the road.

A knuckle also can be damaged due to a failed CV axle or wheel bearing. In this case, I’m talking about a scenario in which a driver ignores the grinding, metal-on-metal noises from a failing wheel bearing, and continues to drive for a long, long time. I’ve seen this exact scenario in the shop before, and it usually isn’t pretty. Eventually, the wheel-bearing bore becomes deformed thanks to the added stress, and the entire knuckle is only good for scrap.

There’s one more thing that could damage a knuckle: overtightening a ball joint or tie-rod end. Ball joints and tie-rod ends usually feature a tapered seat, which becomes tighter as the fastener is tightened. In older knuckles that were made of steel, that tapered bore would hold up pretty well, even if the fastener was a bit overtightened. But the modern aluminum or alloy knuckles are much softer, and they’re susceptible to damage from over-tightening. If the joint is tightened down but it’s still loose inside the tapered bore, the bore is damaged and the entire knuckle will need to be replaced.

What About Time?

So, we know why a customer might replace a damaged knuckle, but what does time have to do with it? That’s easy: Time is money. This applies to both DIY and DIFM customers. DIY customers are trying to get their vehicle fixed and back on the road as quickly as possible, especially if it’s their one and only vehicle. DIFM customers are trying to maximize their efficiency, and keep the shop running smoothly. In either case, if the customer runs into trouble, the results can be costly.

This is especially prevalent with press-in wheel bearings. This type of bearing is quite labor-intensive to remove and replace. After years of exposure to road debris, grit and salt, they can become stuck in place inside the knuckle. In extreme cases, it could take more time and labor to remove and replace a press-in bearing versus simply replacing the whole thing with a loaded knuckle.

On vehicles with aluminum knuckles, you may find that corrosion will form around a pinch bolt, axle nut or snap ring. This corrosion can make it extremely difficult, if not impossible, to remove that fastener. At some point, it makes more sense from a time and money standpoint to simply replace the entire knuckle, rather than get bogged down trying to remove a stubborn fastener.

Advantages of Loaded Knuckles

First and foremost, the nicest thing about a loaded knuckle is that it comes to you pre-pressed, so there’s no need to press out the old bearing, clean everything up and press in the new bearing. There’s no second-guessing if you set the bearing or the hub to the correct depth, or if you inadvertently damaged something by applying too much force with the shop press. That is a huge advantage to the DIY customer who might not have the necessary tools for this type of repair. It’s also helpful to the DIFM customer as it allows them to manage their time much more efficiently.

Customers might think that they can save a little bit of money by only replacing a wheel bearing and reusing the steering knuckle. But those savings can go right out the window if they run into unforeseen troubles during the repair. If they end up damaging other components, or they spend more time than expected simply trying to remove the old bearing, it can spell disaster. DIY customers can end up being without their vehicle for longer than anticipated, and DIFM customers can lose out on other business if the vehicle is stuck on a lift for longer than anticipated.

Replacing the entire knuckle and bearing assembly at the same time reduces the likelihood of a customer comeback, and increases the chances of the repair being completed correctly the first time. Installing a loaded knuckle can reduce installation time by up to 75% depending on the application. Just like a loaded strut, a loaded knuckle can help to take the hassle and guesswork out of a potentially troublesome repair.

The post

link hidden, please login to view
appeared first on
link hidden, please login to view
.

link hidden, please login to view

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Topics

    • By Counterman
      Customers are the core of our business, and communicating with them effectively is critical to our success.
      While each customer (and transaction) presents a unique set of opportunities and challenges, individual customers often can be classified into one of several broad types. Obviously, “profiling” or “stereotyping” an individual customer when you first meet them shortchanges everyone involved, but understanding the kinds of customers that make up your clientele gives us an idea of how to deal with each customer type once we actually get to know them.
      Depending on which marketing firm or consulting group you choose to believe, there are between four and 10 basic customer types. No matter how many categories you prefer to use, it’s the psychology behind these differences that holds the key to connecting with as many of them as possible. You only get one chance to make a first impression, so a “new” customer is the one with the greatest potential. Even if a new customer has familiarity with your business, they may not have experienced it directly. Your advertising, reputation or a personal referral (presumably all positive) have encouraged them to visit your location for their needs. Now is the time to show them what they’ve been missing!
      Consultative selling is a technique that focuses on building a relationship and determining what your products can do for your customer. By concentrating on the customer’s needs, you can further qualify them as one of the many customer types, and then offer the most appropriate solution for their individual situation. The immediate need might be for a battery or brake pads, but discovering the reason behind the intended purchase can open up the conversation in ways that make it easier for you to sell the most appropriate product for your customer. It also can minimize disappointment and build trust, by ensuring that the products and services are truly useful and meet the customer’s expectations.
      Once the new customer becomes an “active” customer, you haven’t entirely sealed the deal. There’s a huge difference between gaining a customer and keeping a customer. An active customer isn’t necessarily a loyal customer, so using what you’ve already learned about their needs makes it a little easier to meet those needs each time. Neglecting or disappointing your new and active customers leaves the door open for them to become someone else’s new and active customers. Building upon each successful transaction (and learning from any less-than-successful ones) helps you turn these types of customers into the most desirable customer type: the loyal customer.
      Loyal customers are at the heart of the 80/20 rule, which states that 80% of your business comes from roughly 20% of your customer base. New and active customers may come and go (sometimes through no fault of your own), but that solid core of loyal customers is what really keeps your lights turned on and your employees paid every week. As 80% of your business, these are the customers you really need to know and understand. Delivering best-in-class service and focusing on being an integral part of their success will help ensure that these customers remain loyal and even advocate for your business!
      With proper care and feeding, we can reap the benefits of that natural progression from “new” to “active” to “loyal,” but along the way we may discover that we have some lapsed or unhappy customers. Timing is critical when addressing these “at-risk” customer types. An unhappy customer (even a loyal one) is likely to become a lapsed customer if we continue to fail them, especially if our competition surpasses us in service, pricing or any other metric. We need to identify and correct the core issues behind their dissatisfaction before that customer has the chance to cozy up to another vendor.
      The at-risk customer tends to taper off slowly, so if you aren’t paying attention, you may not even realize it until it’s too late! If a valued customer does become lapsed, you should still attempt to salvage that relationship by determining what caused the lapse in the first place. The feedback also may prove to be useful in the future when dealing with other customers, who might have similar needs and objections.
      No matter if it’s a retail or a commercial account, knowing the most effective ways to connect with each customer type helps create repeat business and build your brand.
      The post
      link hidden, please login to view appeared first on link hidden, please login to view.
      link hidden, please login to view
    • By Dorman Products
      Steering and Suspension Knuckles | Counterperson Training from Dorman Training Center
    • By Dorman Products
      Steering Components | Counterperson Training from Dorman Training Center
    • By Counterman
      Bryan Miller, vice president of product and category management at Arnold Motor Supply, has been elected chairman of the Alliance Commercial Vehicle and Heavy Duty (CVHD) steering committee for 2024.
      The CVHD steering committee is a collection of Alliance CVHD membership with the purpose of providing guidance on vendor relationships, exclusive national branding and the developing national truck service program.
      The Alliance CVHD program prides itself on industry-leading IT solutions to facilitate ease of business; expansive interchange and product lookups; B2B and B2C solutions; and ensuring truck-part suppliers and repair facilities are found online. The Alliance CVHD steering committee will offer guidance and new ideas that will steer the future of the program.
      Miller will begin serving as chairman of the Alliance CVHD steering committee effective Jan. 1.
      “This is a great opportunity for myself and the Alliance as a whole,” Miller said. “To be a part of something from the beginning is a privilege. The Alliance CVHD team has done a great job of starting this program and we at Arnold Motor Supply look forward to being a part of its growth and future success. We are just getting started, our goal is to make this the strongest CVHD program in the industry.”
      Miller will work directly with other members of the steering committee, as well as the Alliance CVHD headquarters personnel led by Justin Hebert and Mario Gonzalez.
      “We are delighted to have Bryan Miller taking the helm as chairman of the CVHD steering committee,” said Mario Gonzalez, Alliance CVHD program manager. “Bryan’s incredible success in growing the heavy-duty business at Arnold Motor Supply speaks volumes about his expertise. What sets Bryan apart is not just his professional achievements, but his genuine commitment to the Alliance’s CVHD program. His eagerness to share ideas, showcases a leader who not only believes in growth but actively nurtures it. With Bryan steering our committee, we are confident in the continued success of our CVHD program.”
      Those interested in more information or specific program details and membership should contact Mario Gonzalez at [email protected] or visit
      link hidden, please login to view. The post
      link hidden, please login to view appeared first on link hidden, please login to view.
      link hidden, please login to view
    • A-premium Auto Parts:5% OFF with Code GM5.
    • By Counterman
      Fuel injection is as old as the internal combustion engine itself. However, many of the early systems proved to be somewhat troublesome and quirky. The carburetor, by comparison, was simple and dependable, and therefore the fuel system of choice for the majority of mass-produced vehicles through most of the 20th century.
      For those who entered the automotive industry during the reign of the carburetor, fuel injection was so uncommon that as it began to make a comeback during the 1980s, it was largely misunderstood and tagged with the less-than-endearing term of “fuel infection.”
      With the help of electronics and computer control, fuel-injection systems began to improve quickly and followed a course of evolution that introduced many different system designs. Suddenly, we were bombarded with unusual terms and acronyms like Jetronic, Motronic, TBI, MFI, GDI, TDI and many more. While it might have seemed confusing at first with so many different coined terms from so many different manufacturers, ultimately there are only two basic types of fuel injection.
      Why Fuel Injection?
      For efficient combustion to occur, fuel must be atomized first (broken up into the smallest particles possible) so it can mix with the air and vaporize. Only then will it properly burn inside the cylinder.
      The job of a carburetor was simply to allow the air flowing through it to atomize the fuel as it draws it out of the various circuits. Carburetors work very well at doing this, but they also are inefficient in many ways, preventing them from remotely coming close to the efficiency required for the tightening emission regulations of the time.
      This is where fuel injection proved itself a superior method of fuel metering. Fuel injection atomizes the fuel as it exits the tip of the injector. But even more importantly, with the combined advance in electronics and computer controls, it also provides precise control of the amount of fuel – a critical aspect for fuel economy and emission control.
      Indirect Fuel Injection
      Indirect means the fuel is injected and atomized before it enters the combustion chamber. Throttle-body injection (TBI), sometimes referred to as single-point injection, is a type of indirect injection in which the injector is located in a throttle body before the intake manifold. The throttle body looks similar to a carburetor and uses many similar components such as the intake manifold and air cleaner.
      This was done by design, as it was the most efficient and quickest way for auto manufacturers to make the change to fuel injection, while utilizing many of the same components. Port, or multi-point, injection injects fuel into the intake runner just before the intake valve for each cylinder. Still a form of indirect injection because it occurs before it enters the combustion chamber, the advantage is the ability to precisely control the fuel delivery and balance the air flow into each cylinder, leading to increased power output and improved fuel economy.
      Whether an engine is carbureted or fuel-injected, atomization of the fuel is critical for combustion. Many variables affect atomization, and even though a fuel injector initiates the process, the airflow and other objects around it will affect how well the atomized fuel mixes with the air and vaporizes. The location of the injector as well as the design of surrounding components are critical aspects of engine design.
      TBI is at a disadvantage because the airflow is interrupted by the injector – another reason that port injection has the advantage and has made TBI obsolete on newer vehicles.
      Diesel engines are fuel-injected because diesel fuel doesn’t atomize and evaporate like gasoline. It must be injected into an air stream at high pressure to atomize, and the turbulence of the air is an important factor in causing the air and fuel to mix.
      Early on, due to the difficulties of creating an efficient direct-injection system, many diesel engines utilized a pre-combustion chamber that created the necessary turbulence for proper fuel atomization. The fuel was injected into this pre-combustion chamber, making these indirect fuel-injection systems as well.
      Direct Fuel Injection
      Direct means the fuel is injected directly into the combustion chamber. The challenge with this type of injection is the pressure inside the combustion chamber is much higher than that of the pressure in the intake manifold of an indirect-injection system.
      For the fuel to be pushed out of the injector and atomized, it must overcome the high pressure in the cylinder. Indirect systems have a single fuel pump in the tank that provides adequate pressure for the system to operate, usually 40 to 65 pounds per square inch (psi). Direct systems utilize a similar pump to supply fuel to the rail but require an extra mechanically driven high-pressure pump that allows them to overcome cylinder pressure. These systems usually operate at 2,000 psi or higher.
      Direct-injection systems can be identified easily by the location of the injectors going directly into the cylinder head as well as the additional lines and mechanical pump, usually visible above the valve cover.
      The primary advantage of direct injection is that there is less time for the air/fuel mixture to heat up since the fuel isn’t injected in the cylinder until immediately before combustion. This reduces the chance of detonation, or the fuel igniting from the heat and pressure in the cylinder. This allows a direct-injected engine to have higher compression, which itself lends to higher performance.
      Another advantage is reduced emissions and fuel consumption. With indirect injection, fuel can accumulate on the intake manifold or intake ports, whereas with direct injection, the entire amount of fuel sprayed from the injector is the exact amount that will be burned, ultimately leading to more accurate control over the combustion process.
      The overall performance and efficiency of direct injection can’t be matched. However, there are still some disadvantages to it when compared with indirect injection. One of the most well-publicized is carbon buildup on the back of the intake valves. Fuel is a great cleaner, and the fuel spray from a port-injected engine keeps the back of the valves clean. Without it, excessive carbon buildup occurs, leading to interrupted airflow into the engine, reduced performance and an expensive repair.
      While not an issue for typical everyday driving, indirect injection is limited at high engine rpm because there simply isn’t enough time for the injector to release the fuel and for it to properly atomize. Since port-injected engines spray fuel before or as the intake valve is opening and complete vaporization occurs and the air is pulled into the cylinder, there’s no rpm limit with indirect injection.
      Low-speed pre-ignition (LSPI) is a common term you may have heard, and it’s a problem that exposes another chink in the armor of direct injection. The piston and combustion-chamber design of a direct-injected engine is very specific to create the proper air turbulence to completely vaporize the fuel for combustion. At low rpm, the piston is not able to create the proper turbulence, leaving unvaporized fuel pockets that combine with contaminants from oil vapor and carbon buildup, leading to pre-ignition.
      While this problem specifically occurs on direct-injected engines, it can worsen with some engine oils depending on the additives they contain. This is why new oils are advertised to prevent LSPI.
      As engine technology advanced, diesel engines saw changes in piston and combustion-chamber design that allowed them to make the switch to direct injection and realize the same performance benefits.
      So, your two basic types of fuel injection are indirect and direct. There are advantages and disadvantages to both. What’s next? The simplest solution in the book: dual injection. Now manufacturers are building cars with both. Computer control utilizes both systems to eliminate the weaknesses and exploit the strong points of each type of system. It’s the best of both worlds. Wasn’t that easy?
      The post
      link hidden, please login to view appeared first on link hidden, please login to view.
      link hidden, please login to view

×
  • Create New...