It seems like a crystal set I have failed while I was driving.. The set has been used quite a bit, but I was wondering if it's normal for them to fail after a lot of use?

I just want to make sure there's no other reason that they failed!

So it's happened again...
I use a KO Vantage Esprit 2 Type R radio with a KR301F receiver (40mhz) and
the receiver crystal that I mentioned before was a few years old, so I assumed that that was the reason for the failure.

But after using a new 40.865mhz crystal only twice, the (receiver) crystal failed during a race. At the time, the radio gear was unresponsive to all inputs from the radio, and although the servos stopped making any "buzzing"
noises (as normal), they still felt heavy to move. I'm not sure what the
significance of this is, but power was definitely reaching them. Now
with this particular crystal, whenever the receiver module is tapped
the radio gear varies between acting normally, glitching
uncontrollably, or simply being unresponsive to all transmitter
inputs.

I have tried different KO crystals and also a spare KR302f receiver
and all work normally, so the problem seems to be with the 40.865mhz
receiver crystal.

One other thing I did notice was that, with the KR301f reciever (which
I have been using, and both crystals have failed in), when I put a
brand new crystal (or any other crystal) in it and "tapped" the receiver lightly, it would cause an instantaneous, but very brief, glitch in both servos.

Would anyone know why the 40.865mhz crystal would fail so soon? I don't think there#s any excessive vibration of the receiver.. And maybe someone would know about the 301f receiver "twitch"??

Thanks!

You might want to switch to a DSM system. You wouldn't have to deal with crystals.