tuning
I still have my manual and there is no description of how to tune the rig. Nonetheless, it is not difficult. Take out the cotter pins on the turnbuckles, grab the screw pin on the shroud with a pair of vise grips and use a screwdriver to turn the turnbuckle. The trick is that you need to tighten the shrouds on both sides to take up the slack in a balanced way--alternate P & S, I begin with the outer too. There are gauges that you can use to measure tension or you can do it by feel and trial and error.
If you have never touched your shrouds that probably means that they are original? If so they are way past their expected lifespan (some people say 10 years is the serviceable lifespan for shrouds). I replaced mine (1981 H33) about 6 years ago after noticing hairline cracks in the screw pins. If a shroud loosened up suddenly, I would be concerned about its integrity.
