Throw away fasteners

[hrdware101]

I was perusing the shop manual for my 2018 F3LTD and I noticed that a lot of fasteners, like the brake caliper bolts, are throw aways. Why is that? I have been doing maintenance on all my vehicles, including brakes, and I never came across any fasteners that needed to be discarded and replaced with new ones (unless they show signs of unusual wear). I understand the need to replace cotter pins, o-rings, gaskets, etc, but I just cannot wrap my head around the throw away bolts.
Maybe someone here can enlighten me?
Thanks

 

[PMK]

Many of the threaded fasteners from BRP have preapplied locking compound. In simple best practices, if you reuse the fastener, apply Loctite 243.

 

[Chupaca]

Safety issue. Threads can stretch with repeated use heat and cold can affect strength of the bolts but mostly in the safety areas they will recommend replacing many parts. :thumbup:

 

[spyder01]

If the torqueing procedure requires the use of a torque angle gauge instead of a regular torque wrench then you have what is called a torque to yield bolt.TTY bolts are commonly used on head bolts and a few other locations although Ive never seen them used on calipers.As the bolt is tightend it stretches and will stay that way,if reused it may break.I think the trend nowadays is for the manufactuer to cover their asses and sell more parts.Use a medium strength Loctite and read the torqueing procedure carefully.

 

[Bfromla]

$ell MORE parts! According to BRP only a dealer tech is supposed to work on those parts anyway $$$they been "certified":read::wrong:

 

[PMK]

You guys are seriously overthinking this. The threadloc is one time use, new bolts have new threadloc on them, ensuring the as designed anti loosening properties are retained.

The body panel bolts, holding the plastic on, the antenna, the brake caliper bolts and more are certainly not torqued until taking a permanent stretch, or torque to yield is found. Simple torque wrenches, tightening to essentially standard torques plus run down.

 

[JerryB]

Hi 101,

Re: I never came across any fasteners that needed to be discarded and replaced with new ones

In years passed, I have owned two 356 Porsches. For both of those cars, the bolts that hold the calipers in place are a 1-time only bolts.

This is because when they are torqued properly, they have stretched ever so slightly; enough that Porsche considers them no longer usable.

IMO it is a small cost to make sure every is OK.

Jerry Baumchen

 

[BLUEKNIGHT911]

If the torqueing procedure requires the use of a torque angle gauge instead of a regular torque wrench then you have what is called a torque to yield bolt.TTY bolts are commonly used on head bolts and a few other locations although Ive never seen them used on calipers.As the bolt is tightend it stretches and will stay that way,if reused it may break.I think the trend nowadays is for the manufactuer to cover their asses and sell more parts.Use a medium strength Loctite and read the torqueing procedure carefully.

:agree::agree: …….. The bean counters at BRP are mostly concerned with WARRANTY problems. I'm surprised BRP doesn't tell you to REPLACE the " AXEL " every time you adjust it !!!! ………….jmho …. Mike :thumbup:

 

[ofdave]

Hi 101,

Re: .

In years passed, I have owned two 356 Porsches. For both of those cars, the bolts that hold the calipers in place are a 1-time only bolts.

Jerry Baumchen

I have also owned 356 Porsches (one 1957 Speedster, one 1961 Karmann bodied coupe, one 1963 1600 S). None of them had disc brakes.

Yours must have been 1964 or newer 356C.

 

[JerryB]

Hi ofdave,

Re: Yours must have been 1964 or newer 356C.

Yup.

Jerry Baumchen

PS) The difference between the '64 & the '65 was that the '64 had a mechanical tach & the '65 had an electrical tach.

 

[hrdware101]

I am still not convinced. All the cars and bikes I owned and serviced (I never owned a Porsche) had reusable caliper bolts. Maybe those are a few cents more expensive to use, and this way BRP can save a chunk of cash but, as usual, us -the owners will have to pay for new bolts every time the brakes are serviced. Since probably nobody else makes bolts that are compatible, BRP can charge whatever they want for them. It's a win-win for BRP!

 

[dondje]

I was perusing the shop manual for my 2018 F3LTD and I noticed that a lot of fasteners, like the brake caliper bolts, are throw aways. Why is that? I have been doing maintenance on all my vehicles, including brakes, and I never came across any fasteners that needed to be discarded and replaced with new ones (unless they show signs of unusual wear). I understand the need to replace cotter pins, o-rings, gaskets, etc, but I just cannot wrap my head around the throw away bolts.
Maybe someone here can enlighten me?
Thanks

My VW and Audi both have lots of single use fasteners. The Ford F350 and Expedition are older and do not. It is my understanding that these fasteners are designed for a single torque. When they are torqued to spec, they stretch a little. This is supposed to help the fastener maintain its torque hold better because it wants to pull back to original length, with or without Loctite. The problem with using this type of fastener a second time is that it was not designed for a second use. The stretch is not supposed to turn out the same a second time. Thus it is not supposed to have the factory holding power that it originally had at the first use required torque. This is not an issue as to whether there are fasteners that can be torqued over and over. They are available and can even be used to replace the factory fasteners. The issue is that the fasteners in question were specially designed to be used only once. To do otherwise should be at ones own peril and with a void of applicable warranties.


Regards,


Don

 

[JerryB]

Hi Don,

Re: My VW and Audi both have lots of single use fasteners. The Ford F350 and Expedition are older and do not. It is my understanding that these fasteners are designed for a single torque. When they are torqued to spec, they stretch a little. This is supposed to help the fastener maintain its torque hold better because it wants to pull back to original length, with or without Loctite. The problem with using this type of fastener a second time is that it was not designed for a second use. The stretch is not supposed to turn out the same a second time. Thus it is not supposed to have the factory holding power that it originally had at the first use required torque. This is not an issue as to whether there are fasteners that can be torqued over and over. They are available and can even be used to replace the factory fasteners. The issue is that the fasteners in question were specially designed to be used only once. To do otherwise should be at ones own peril and with a void of applicable warranties.



^^^^^^ This 100%; and very well written.

Jerry Baumchen