I learned me something today about torque-to-yield bolts.

[themechanic]

This might save a life.

 

[WileE]

These have been coming more common in recent years. Good info.

 

[#41]

Why build in what will be a failure point for DYI'rs and untrained/unknowing mechanics? Most cars are built without torque-to-yield bolts on the calipers and they function just fine. What benefit of using these bolts outweighs the risk of bolt failure when they fail to get replaced? It's a failure of basic engineering practice.

Thanks for posting. I didn't realize the world had reached this level of stoopid yet. It's getting hard to keep up with.

 

[themechanic]

I just replaced my upper control arms on the Coronet and, in the process, found both bolts had come loose on the driver's side caliper bracket.

 

[DeltaV]

I just replaced my upper control arms on the Coronet and, in the process, found both bolts had come loose on the driver's side caliper bracket.

You're supposed to cross-thread them and run'em down with the impact driver on old cars.


Don't forget to glob on the antiseize compound.

 

[dodgeboy440]

Why build in what will be a failure point for DYI'rs and untrained/unknowing mechanics? Most cars are built without torque-to-yield bolts on the calipers and they function just fine. What benefit of using these bolts outweighs the risk of bolt failure when they fail to get replaced? It's a failure of basic engineering practice.

Thanks for posting. I didn't realize the world had reached this level of stoopid yet. It's getting hard to keep up with.

Torque to yield bolts have a built in malleability by design . They STRETCH ….
Gee let’s put TTY Bolts On A Diesel ?!
What happens when they Stretch ?
Hmmmm 18-1 Compression Ratio . How About 30psi of boost ?
Do you want fasteners on critical components that are designed to stretch ?
It’s up to you .
if a fastener stretches too much doesn’t it
Lose its clamping force & come loose ?
Again it’s your choice to use or not .
Grade 8 / NAS / Aircraft Spec . / ARP are your friends. Especially IF performance is the goal .
PS
Kudos To The Shop & Technician For Telling It
Like It Is ….
&
Do you ever wonder if profit is the motive ?

“ choose wisely grasshopper “…

 

[j-c-c-62]

That is a new awareness on my part, being my new car repairs are rather limited

As much as I detest more regulations, and as long as NHRA requires new seat belts every 2 years, how about this law:
FMVSS? requires any part sold that requires removal of one time/torque to yield fasteners include all needed new replacement fasteners to make the repair.

I'm open to any other suggestions/compromises, but it took twenty years to finally stop removing my shoes to ride an airplane after one failed incident.

BTW, ALL bolts tightened any amount stretch, when they "yield", they don't return to original dimension.

 

[khryslerkid]

I deliver parts to a lot of shops and I only know of a couple that will order TTY replacement bolts when doing rotor replacements. The one shop works mainly on school bus Chrysler vans and he is religious about ordering them with rotors. We carry quite a few TTY bolts and they are mostly Dorman brand because the dealers don't have them.

 

[Kern Dog]

The dude lost me when I saw he had a man bun.
No thanks.

 

[68-500]

I really don’t understand TTY bolts anyway. If you tighten a bolt to a point where it yields you have already made it weaker. Just put regular f’n bolts in stuff and be done with it.

 

[junior340]

Nice reminder thank you

 

[Cop car wagon]

TTY bolts do stretch. They also spring back.
Swapping studs in for TTY head bolts on all alumium engines with MLS gaskets can lead to gasket failure as the stud over compresses gasket, and clamping is lost.

 

[Don Frelier]

 

[j-c-c-62]

I really don’t understand TTY bolts anyway. If you tighten a bolt to a point where it yields you have already made it weaker. Just put regular f’n bolts in stuff and be done with it.

That is not necessarily true, the issue here is when it starts to first "yield", which I already defined for this discussion, and when it fails can be rather far apart, meaning when it starts to "neck" down it is becoming thinner in cross-section and ultimately weaker.

 

[gtxdana]

It's highly unlikely the bolt that the man-bun wearing, internet sensation was waving around would even be used to secure a caliper torque member to an upright.

Just because a bolt torquing procedure lists an angle value doesn't necessarily mean the bolt is a one-time use torque to yield bolt.

An angle torquing procedure is used to ensure the proper clamping load (stretch) of a fastener taking out the effects of friction from dirt, rust, oil, thread locking compound, etc. on the final torque value.

A threaded fastener moves a certain amount per degree of rotation. In the angle torque procedure, the fastener is tightened to a lower torque value before excessive friction comes into play, then the fastener is turned a set number of degrees which results in a more consistent stretch of the bolt.

If the fastener is a one-time use item, the service manual will spell that out in the repair procedure.

 

[Tony Tee]

How many of these type of bolts do our old muscle cars have that i don't know about ? ?

 

[c body convert]

nothing made by butt pucker more than giving tty head bolts that extra half turn and hoping they didn't strip out

 

[padam]

It's highly unlikely the bolt that the man-bun wearing, internet sensation was waving around would even be used to secure a caliper torque member to an upright.

Just because a bolt torquing procedure lists an angle value doesn't necessarily mean the bolt is a one-time use torque to yield bolt.

An angle torquing procedure is used to ensure the proper clamping load (stretch) of a fastener taking out the effects of friction from dirt, rust, oil, thread locking compound, etc. on the final torque value.

A threaded fastener moves a certain amount per degree of rotation. In the angle torque procedure, the fastener is tightened to a lower torque value before excessive friction comes into play, then the fastener is turned a set number of degrees which results in a more consistent stretch of the bolt.

If the fastener is a one-time use item, the service manual will spell that out in the repair procedure.

I agree with gtxdana on this.

The guy in the video is usually pretty good. But mechanics are sometimes out of thier depth when it comes to strength of materials. That is generally the province of engineering.

 

[j-c-c-62]

It's highly unlikely the bolt that the man-bun wearing, internet sensation was waving around would even be used to secure a caliper torque member to an upright.

Just because a bolt torquing procedure lists an angle value doesn't necessarily mean the bolt is a one-time use torque to yield bolt.

An angle torquing procedure is used to ensure the proper clamping load (stretch) of a fastener taking out the effects of friction from dirt, rust, oil, thread locking compound, etc. on the final torque value.

A threaded fastener moves a certain amount per degree of rotation. In the angle torque procedure, the fastener is tightened to a lower torque value before excessive friction comes into play, then the fastener is turned a set number of degrees which results in a more consistent stretch of the bolt.

If the fastener is a one-time use item, the service manual will spell that out in the repair procedure.

I agree with everything except the last sentence. There should be required a marking on the bolt (a big star?) that indicates it's a one-use bolt, end of story.