[TonyM]

Tresrey shafts are good, they use two circlips. I run them in the Tresrey shock body. I believe that they are marginally smaller in diameter than the Durango, so maybe if you were to use them with Durango bodies then you might need to also use the Tresrey inserts to ensure a tight fit. The 'O' rings are standard size. Oh, and of course you would have to use their pistons.

I should also say that this is on just one of my four Durango buggies. I have standard shafts on the other three and never had a probelm with the scew coming loose. Are you threadlocking the screw?