Pawnee landing gear

On Friday, August 21, 2015 at 9:12:52 PM UTC-4, son_of_flubber wrote:
On Sunday, December 6, 2009 at 2:06:24 PM UTC-5, wrote:

We also change bolts at least once a year.
UH

Is this just 'common sense' or is it recommended in a maintenance manual or AD?

I'm looking for information specifically about the failure of one of these bolts. I've scanned through the Piper PA-25 AD index and did not find an AD that mentions them. Are there known cases of these bolts failing and gear collapsing?

Maybe the information is out there and I just don't know how to find it. Sharing of your expertise is very much appreciated.

It is a practical response to having had failures of the gear mounting brackets as well as bolts.
Ours is a 150 Pawnee converted to 180 so it has a somewhat lighter gear than the later 235. All the bolts on the 235 are one size larger.
Our field is rough and we do about 1000 landing a year with this airplane.
I am not aware of any AD nor any maintenance manual info on this.
UH