Stiffening plate removal / reinstallation

[X5only]

FCPEuro's life-time replacement warranty policy made replacing the stiffening plate bolts a no-brainer for me - just replace them if you purchased them from FCPEuro! Why? You get your money back when you send in the old bolts and buy new ones from them, as per their life-time replacement terms. Note - your money back in the form of payment you purchased the new ones, as opposed to a store credit . So essentially the only cost to you for replacing the bolts is the shipping costs for sending the old ones in. Shipping is free when purchasing. Does that now settle this debate for good?

[crystalworks]

Originally Posted by X5only

FCPEuro's life-time replacement warranty policy made replacing the stiffening plate bolts a no-brainer for me - just replace them if you purchased them from FCPEuro! Why? You get your money back when you send in the old bolts and buy new ones from them, as per their life-time replacement terms. Note - your money back in the form of payment you purchased the new ones, as opposed to a store credit . So essentially the only cost to you for replacing the bolts is the shipping costs for sending the old ones in. Shipping is free when purchasing. Does that now settle this debate for good?

Good idea! But no... lol, no it doesn't.

There is no debate really. It's BMW's recommendation to replace vs. the years of experience from owners, indys, and even BMW's own mechanics who reuse the bolts. But then again BMW recommends replacing all suspension fasteners anytime their are touched too... nobody does that either (unless a new part is being put in that came with fasteners). Each owner will have to choose to reuse them... or not. With as often as my plate is removed (3 to 5 times a year) I wouldn't even go for the FCP Euro swap out due to the hassle involved. Cost is only one factor.

[Fifty150hs]

Originally Posted by crystalworks

Good idea! But no... lol, no it doesn't.

There is no debate really. It's BMW's recommendation to replace vs. the years of experience from owners, indys, and even BMW's own mechanics who reuse the bolts. But then again BMW recommends replacing all suspension fasteners anytime their are touched too... nobody does that either (unless a new part is being put in that came with fasteners). Each owner will have to choose to reuse them... or not. With as often as my plate is removed (3 to 5 times a year) I wouldn't even go for the FCP Euro swap out due to the hassle involved. Cost is only one factor.

The only reason that has any substance to it that supports replacing these particular bolts is that they are torqued to a level and THEN torqued to an additional percentage (90 degrees or what ever). That means they are being stretched. None of the other bolts on the car that I've run in to that BMW says should be replaced have this requirement. That tells me the bolts are fine to be reused. I always put blue Loctite on them, but I don't replace them. I haven't had to pull my skid plate yet, but given the torque requirements involve "stretching" already torqued bolts, I'll probably replace them when I have to drop the plate. Just my 2 cents.

[bcredliner]

The justification for reusing the bolts is always interesting and fun reading. Lots of personal experience, it's a scam, accumulation of what others do or shade tree engineering guessing.

Here are some sources that provide information about Torque to yield bolts such as those used to secure the reinforcement plate. Most of it is about cylinder head bolts. My guess is after digesting this input, even if the cost of the bolts was the same as those used to secure the reinforcement plate, the common sense folks would not reuse the head bolts. The only difference is we know why the bolts should not be reused and what can happen if we do. https://www.youtube.com/watch?v=xFzTZG4eU70 https://www.freeasestudyguides.com/a1_4.html https://video.search.yahoo.com/searc...bf&action=view. I'm not trying to change minds. I am pointing out that until you know for sure why TTY bolts are used to secure the reinforcement plate and what happens if you don't, the risk of reuse is not quantifiable. The risk could be low or could be high, none of us know where it falls. Are you having fun yet?

[crystalworks]

Originally Posted by bcredliner

The risk could be low or could be high, none of us know where it falls.

Agreed. But at some point collective information becomes accepted practice. Some will never change their mind, and that's fine. If it gives someone the warm and fuzzies to reuse these bolts... have at it. If it makes you feel safer or otherwise in a better place, it makes sense.

Head bolts are an apples/oranges analogy though. No one should ever reuse head bolts. There are TONS of documented cases/information of what can happen reusing them. And they are cheaper than the stiffening plate bolts/nuts anyway and not a regularly removed service item. There are no cases of any negative affects of reusing the stiffening plate fasteners except for one user here I believe who reported a squeak or noise from the plate. I am not trying to convince anyone of anything. Just counterpointing your last post.

[X5only]

If these bolts were a dime a dozen, we certainly wouldn't be talking about whether to replace or not. They are expensive and FCPEuro has an answer for us. My strategy in replacing them with new ones is to wait until I've completed the final-final-done-done task requiring dropping the reinforcement plate. Otherwise I just re-use those bolts in the interim.

[bcredliner]

Originally Posted by crystalworks

Agreed. But at some point collective information becomes accepted practice. Some will never change their mind, and that's fine. If it gives someone the warm and fuzzies to reuse these bolts... have at it. If it makes you feel safer or otherwise in a better place, it makes sense.
Collective information can become the practice. The amount of input here is insufficient to be extrapolated to an accepted practice. Even if the input were sufficient it is still conjecture so a decision to reuse the bolts is flawed.
Head bolts are an apples/oranges analogy though. No one should ever reuse head bolts. There are TONS of documented cases/information of what can happen reusing them. And they are cheaper than the stiffening plate bolts/nuts anyway and not a regularly removed service item. There are no cases of any negative affects of reusing the stiffening plate fasteners except for one user here I believe who reported a squeak or noise from the plate. I am not trying to convince anyone of anything. Just counterpointing your last post.

Using head bolt data was intentional. The way it is apples to apples is both use torque to yield bolts and once they are torqued they can't be properly torqued again. The number of instances of failure has nothing to do with it. There are no cases that you know of where the plate bolts failed, that is different than no cases. I contend that it is so hard to justify the cost of the bolts that we jump to accept any input that even remotely supports not making the purchase. Cost should not be considered in the decision. Same input--until we know why BMW uses TTY bolts and the associated level of risk the only think we know is we saved money. I'm not trying to convince anyone of anything either.

[crystalworks]

Originally Posted by X5only

If these bolts were a dime a dozen, we certainly wouldn't be talking about whether to replace or not.

Possibly, but I don't think it's the only reason. I think, more often than not, they get reused because it's easier to and individuals don't have access to the parts dept or WorldPac. Simple. Couple that with the real possibility of having to drop that plate 5-10 times a year and the motivations are easy to see, including cost of course.

Originally Posted by bcredliner

Even if the input were sufficient it is still conjecture so a decision to reuse the bolts is flawed.

Disagree. At what point something deserves to become standard practice is subjective and will vary widely.

[bcredliner]

Originally Posted by crystalworks

Possibly, but I don't think it's the only reason. I think, more often than not, they get reused because it's easier to and individuals don't have access to the parts dept or WorldPac. Simple. Couple that with the real possibility of having to drop that plate 5-10 times a year and the motivations are easy to see, including cost of course.

Disagree. At what point something deserves to become standard practice is subjective and will vary widely.

A standard practice is not subjective. It is based on a particular set of parameters that prove it is the fact based process.

The number of times the plate is dropped a year should not have anything to do with it. Why would anyone need to drop the plate 5-6 time a year?
This is the best debate of this issue we have had since there seems to be some consensus that high cost drives the decision to reuse the bolts when it clearly should not.

[Purplefade]

I guess it all comes down to - data, consensus, collective information, sufficiency or insufficiency aside, if you want to replace your bolts, replace them, if you don’t want to replace your bolts, don’t.

Kind of like how many licks does it take to get to the center of a tootsie pop, short of finding the engineers that designed the plate and the bolts and asking them their logic behind it..., the world may never know


Though it has been an enjoyable debate to follow.