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Not sure about the heated mirrors but it would not explain the trim doing the same thing.
The mirror is literally warping and pulling away from the truck, but it's also the trim piece at the top between the doors. Same thing, warping and pulling away.
It's probably a combination of things causing this. (I have been in injection molding plastics since 1983.) All molded plastic parts have varying degrees of residual stress in them. Plastic molecules are very long compared to other materials and they "stretch" when they are pushed into a mold. Those molecules want to relax to their "neutral" state but can't completely because the cooler mold freezes the molecules in place. (This is what holds the shape of the mold and results in the shape of the plastic part.)
If the stress is high in the molded part, it increases the likelihood it will warp. This warpage can happen immediately or shortly after the part is removed from the mold. If it's bad enough, the part will not even fit in the assembly. If that's the case, the molder can hold the part in the mold longer to minimize the warp. However, that doesn't mean the stress causing the warp is eliminated, it's just "locked" in place increasing the possibility it could warp later.
If you inject the plastic quickly into a hot mold you generally get less stress in the part, but that's not always possible given all the interactions of flow rates, temperatures, pressures, etc. that play into the process. Also coming into play is the surface finished required on the molded part. Fast filling usually results in "blush" on the molded part which makes it look like poo.
I'm fairly confident that this part is polypropylene which is prone to warpage. A slow injection speed to keep the surface finish good increases the stress and the potential for warp. Without seeing the inside of the part, I'd suspect there are some thick sections which take a long time to cool. If so, the molder would likely run the mold colder to speed up the process. Cold molds tend to "freeze" the stress in place, also increasing the possibility of warpage.
The warp could occur over a long period, but is very rare. If a heat source is raising the temperature of the part, that can accelerate the warpage.
I'm not saying this is a design flaw, nor a processing flaw. The sheer numbers of these components that have been produced confirm this is an anomaly. If it were design or processing you'd been seeing thousands of these turning up.
If the vehicle is new I feel it should be covered under warranty. If there is an odd heat source at play it should be identified and eliminated, otherwise you risk the same thing happening again.
Also keep in mind that this is close to the mirror. There may be a reflection of sunlight coming from somewhere that is being redirected onto the shroud covering the mirror mount. It may not be obvious and it may be only occurring during a certain time of the day. Repeated exposures could cause this to gradually begin and get worse over time.
[MENTION=195154]chickenwire[/MENTION]
Thanks for the explanation and info - makes a lot of sense. I have seen other posts on the internet of others with the similar situation, but certainly not thousands. So, I guess proving there was a certain production group that the molding was incorrectly handled would be difficult.
Just seems right to me that a truck which was purchased just a few months earlier would be a situation that Ford and/or Galpin would be willing to correct. It has super low miles and way within warranty.
Would you agree that double-stick tape to hold the trim molding in place might be a design flaw?
@chickenwire
Thanks for the explanation and info - makes a lot of sense. I have seen other posts on the internet of others with the similar situation, but certainly not thousands. So, I guess proving there was a certain production group that the molding was incorrectly handled would be difficult.
Just seems right to me that a truck which was purchased just a few months earlier would be a situation that Ford and/or Galpin would be willing to correct. It has super low miles and way within warranty.
Would you agree that double-stick tape to hold the trim molding in place might be a design flaw?
It's always possible that there was something "odd" about your particular part and it's processing, but if it were a problem with inconsistent manufacturing, procedures, etc it generally wouldn't be "here or there" as we discussed.
If it was purchased new, it's warranty all the way in my eyes. If it was purchased used, you'll have to check what is covered in the "warranty".
As for 2-sided tape being a design flaw - no way. 3M has some products in their VHB (very high bond) tape series that are some seriously sticky SHtuff. It's held on body side molding for 30+ years. That is not a "fix" - it is used all the time on more things than you can imagine.
12-10-2014, 11:06 AM
Built FORD tough, but melts in the heat!
