WATCH: TTY Bolts For Suspension And Brake Components (Torque + Angle)

WATCH: TTY Bolts For Suspension And Brake Components (Torque + Angle)

In this Tech Minute, Andrew Markel covers everything about TTY bolts and how their build could affect your next suspension repair. Brought to you by MEYLE.

In this Tech Minute, Andrew Markel covers everything about TTY bolts and how their build could affect your next suspension repair.

Brought to you by MEYLE.

 

Additional information from Andrew Markel:

What do some ball joints, tie rods and suspension components have in common with engines? The answer is torque-to-yield (TTY) fasteners. These bolts and studs that stretch are becoming more common on vehicles — not just under the hood, but under the car. TTY fasteners are mounting fasteners which are torqued beyond the state of elasticity, and therefore, undergo plastic transformation that causes them to become permanently elongated.

Some ball joints, and almost all tie-rod ends, use a tapered stud and hole with a nut on top to secure the stud to the knuckle. The 7-10º angled taper, along with a threaded stud and nut, lock the components together by tensioning the nut and stud. TTY ball joint and tie-rod studs have two advantages. First, they can weigh less and still apply the same clamping loads. Second, the clamping loads are more consistent and controllable.

Installation

TTY ball joints and tie rods are usually installed dry. Do not apply any oil, grease, assembly lube or sealer on the stud or tapered bore. The reason why is that lubricants reduce friction when a bolt is tightened. This actually increases the torque load on the bolt or stud, which may overload and stretch a TTY bolt too far, causing it to break.

The increased torque can also cause the female part of the taper to crack as too much clamping force is applied.

Aluminum knuckles, upper control arms and ball joints can be damaged if not tightened using the correct procedure. Knuckles and upper control arms are aluminum and can be damaged if a torque wrench and torque angle gauge are not used. No matter if you go too tight or too loose, if you fail to use correct tools and procedures, you could be buying the customer a knuckle.

Many ball joints may have an initial torque spec as low as 15-30 ft/lbs, and torque angles are between 140º and 225º.

Reusing TTY Items

Make sure you check the service information to see if a TTY ball joint or tie-rod end is reusable after it has been removed. Some manufacturers recommend that a joint be replaced, while others do not indicate if it should.

For the technician trying to avoid dealing with this conundrum, it may be better to remove the control arm with the knuckle or separating tie rods between the inner and outer shaft. It is easier and less expensive to sell an alignment rather than face the possibility of a ball joint replacement in some cases.

Identifying TTY Ball Joints and Tie Rods

The metallurgy and heat treatment of TTY bolts and regular bolts is different, and you can sometimes tell one from the other by their appearance. Always make sure to check the service information to get the right torque for a suspension component regardless of the type of fastener. If you see an initial torque spec along with an angle in degrees, it is a TTY fastener.

You May Also Like

EV Safety Basics on the Shop Floor – Part II

As long as you follow the EV guidelines, you are going to have to use the proper PPE and insulated tools.

Staying safe while working on an electric vehicle requires the correct shop equipment as well as the correct personal protective equipment (PPE) and shortcuts are simply not an option. Let’s take a look at everything you are going to need.

We’ll start with PPE and electrical safety gloves. Class zero electrical insulating gloves rated for 1000 volts are required for EV service. Simply put, these gloves prevent high voltage from traveling through your hands, and they must be tested every time you use them by checking for a pinhole or any damage that could allow voltage to pass through a glove. A glove inflator is the most efficient way to do this. Insulating gloves must also be clean and dry so there are no conductive substances that can allow high voltage to travel outside the glove to your arm. Treat these safety gloves with extreme care. They can be damaged easily and they’re sensitive to UV rays, so they should be stored in a dark, dry environment. A ventilated UV-resistant bag is the best option. Safety gloves must also be re-certified every six months. You’ll also wear them with a leather outer glove to protect them, most prefer to wear an inner cotton glove as a liner to allow your hands to breathe.

EV Safety Basics on the Shop Floor – Part I

It’s critical to utilize OEM service information and procedures for each and every hybrid or EV.

Autel MaxiSYS Ultra Enhances Efficiency At Mighty Auto Pro

Time is money in vehicle repair, and the Autel MaxiSYS Ultra is all about enhancing technicians’ diagnostic prowess.

Empowering the Automotive Aftermarket Through Collaboration

Distributors, manufacturers, training institutions, associations and service providers all help automotive professionals stay ahead in a market that is constantly evolving with new technologies, trends and customer demands.

Understanding LSPI & Engine Oil

Using the correct manufacturer-recommended oil is crucial for peak performance and long-lasting engine health.

Other Posts
Randy Breaux, Group President, GPC North America, Talks to AMN Drivetime

At NAPA, “Breaux Knows” business relationships, ABCs to avoid, and serving the automotive professional.

Serpentine Belt and Drive System Maintenance

Properly maintaining the entire drive system prevents premature belt wear and system failure, ensuring customer satisfaction and vehicle reliability.

How Modern Car Sensors Optimize Performance and Emissions

Learn how Standard ensures accuracy, speed, and durability in their sensors to maximize engine performance and efficiency.

Chassis Parts and Alignment Angles

Knowing why the adjustment is required is critical to performing the total alignment.