Lycoming dipstick tool

thingiverse

I tighten my Lycoming 0-320 oil cap pretty snug for reassurance, but occasionally it's a real struggle to unscrew later down inside the cowling with limited access. To get more leverage, I fashioned this tool to attach to the end of my 3/8" square drive T-handle. It fits perfectly onto the dipstick cap and grips it firmly enough to withdraw without touching it directly. I'm not certain if it will fit all Lycoming oil dipsticks, but it looks very similar to the one on my old IO-540 engine, so I believe it should work for your engine as well.