TTY Fasteners: Securing the Future
Torque-To-Yield (TTY) fasteners are becoming a big part of automotive engineering. They can be found on many different parts of the vehicle. TTY fasteners are mounting fasteners that have been torqued beyond the point elasticity causing them to become permanently elongated. Ball joints and tie-rod ends are locked together by a stud with a nut on the end. As they tighten, the stud becomes tensioned and clamps the parts together. The two big advantages of a TTY fastener are weighing less but still applying the same clamping load, and having more consistent and controllable clamping loads. TTY fasteners were first used to clamp together bi-metal components such as aluminum and cast iron engines, and aluminum brake knuckles. TTY fasteners are now found on all kinds of vehicles.
Identifying TTY Ball Joints and Tie Rods
TTY studs can be identified by sight because of the inset hex head at the end of the stud. Always check the service information to get the right amount of torque for a suspension component TTY or otherwise.
If a ball joint or tie-rod is not installed correctly it can cause a crash. Install TTY fasteners dry. Do not oil, grease, or lubricate in any way because it can cause the bolt to become overloaded when tightened and break. DO NOT USE AN IMPACT DRIVER! EVER! Impact drivers can cause the parts the TTY fastener is being installed into to break and be replaced. Never guess when tightening down a TTY component. If a torque-to-yeild component is not installed correctly, it can result in a catastrophic failure.
Reusing TTY Items
Check with the manufacturer to see if the component can be used again after removal. it may be better to remove the control arm with the knuckle or separating tie rods between the inner and outer shaft.