Eric Greenwell wrote:
The struts in my Cobra are 12 years old and just as strong as when I got
it; the ones in my mini-van generally go 8-10 years. I think the metal
pieces around Bob's struts need cleaning and grease, as bumper
mentioned. My trailer needs it every 5 years or so, or it gets a bit
balky regardless of the temperature.

I'm with Eric. MY Cobra trailer is nearly 15 years old and the struts
are still incredibly strong. My ASW 24, on the other hand [it was an
extra-cost accessory that came with the trailer ], has a gas spring
that holds up the canopy that has needed replacing for some time (I
haven't been brave enough to dive into the assembly yet). The gas
spring in my LS-3 landing gear seemed to go 3-4 years before it got
soft. And, worst case, I had a spare LS-3 gas spring in my tool box for
some years that was marginal by the time it was needed to install it.

I've never opened my Cobra's square tube linkages where the gas springs
live but I suspect one reason for the longevity is that the springs are
mounted so that the lubricating oil is always around the piston rod and
seal rather than up at the higher end of the cylinder where it doesn't
do any good. IIRC, one problem with my LS-3 gas spring was that it was
mounted so that it was in the "correct" position when the gear was
extended but upside down when retracted (or vice versa). On my Cobra
trailer, it's easy: just mount them in the correct position and they're
always oriented that way.

Dust and grit that settle on the piston rod and abrade the seal also
shorten the life. My Cobra springs are inside the trailer but the ones
on my 1978 Komet trailer were mounted unprotected from the weather
outside the trailer. I believe they also changed orientation as they
extended meaning that the oil was at the wrong end of the cylinder part
of the time no matter what.

It also could be that gas spring technology is simply better now than
it used to be.

Chip Bearden
ASW 24 "JB"