Can you reuse a stretch bolt?
Can you reuse a stretch bolt?
stretch to ensure proper securing when tightened down. (Bolts with Specification: Torque plus Angle). Some of these bolts can be reused, if you torque them to the same torque that you would use for a normal bolt of the same size, pitch, lubrication factor, and strength rating.
Do I need to replace stretch bolts?
All fasteners that indicate a torque value, then additional rotation are “stretch to yield” bolts. These bolts do need to be replaced. They cannot be re-used because they are now smaller in diameter after stretching, this changed the effective clamping load to torque relationship making them useless.
Can you use stretch bolts twice?
However, because the tightening procedure does permanently stretch the bolt, there is some risk of breakage if the bolt is reused. And since there is no way to tell how many times a bolt has been reused, it doesn’t make any sense to reused TTY bolts – the risk far outweighs the replacement cost of used bolts.
Can You reuse stretch bolts on a subframe?
NOTE on Subframe: Be warned that if you reuse the stretch bolts it is VERY likely your cars front end will develop a creak when cornering, accelerating briskly and braking moderate-heavily. Either replace the bolts or get a the Tyrol bushing kit to center the bolts.
What happens when a head bolt is stretched too far?
This is the point where the bolt can stretch no further without being permanently deformed. Like a rubber band, a head bolt under load will stretch and spring back to its original length when the load is released. But if stretched too far, the bolt will either become permanently elongated or break.
Is it possible to tighten front pinch bolts?
It can absolutely be done though. Front pinch bolts: 70Nm +180 degree additional turn (tighten the nut while holding the M14 triple square in place. Updated from 90 degree turn) If your car has a light leveling sensor on the driver’s side lower control arm, remove it before you do anything else so you don’t forget.
What should head bolts be lubricated with before installation?
As a rule, the threads and underside of the head on most standard automotive head bolts should be lubricated with motor oil before the bolts are installed. The torque values specified by the engine manufacturer are typically based on oiled threads and fasteners – not dry fasteners.
What is the deal with all ” stretch ” bolts?
Man, what a pain to work on your car on the weekend and then never be able to put anything back together because you do not have brand new “always replace” bolts. They are also known as “stretch bolts”, or “torque to yield”. Since the A4s VW uses them everywhere it seems :
This is the point where the bolt can stretch no further without being permanently deformed. Like a rubber band, a head bolt under load will stretch and spring back to its original length when the load is released. But if stretched too far, the bolt will either become permanently elongated or break.
As a rule, the threads and underside of the head on most standard automotive head bolts should be lubricated with motor oil before the bolts are installed. The torque values specified by the engine manufacturer are typically based on oiled threads and fasteners – not dry fasteners.
Why do you have to stretch a head gasket wrench?
Engineers discovered they can get much more even clamping on the head gasket if all the bolts are evenly loaded. Since variations in friction between bolts always causes some uneven loading, stretching the bolts guarantees all the bolts will exert the same clamping force regardless of the torque reading on the wrench.
