Had been mowing for 45 minutes and my RC2072 just stopped cutting. The “shear” bolt connecting the pto to the gear box had broke without me noticing. I am certain I didn’t hit anything (at least not today), and I am also 70% sure my slip clutch is in working order. The mower is 4 yrs old. Has anyone else ever had this bolt break? I found the broken bolt on the mower, there are 6 diagonal lines on the hex head. As mentioned, I do have a slip clutch. I spun the drive shaft on the gear box with a screw driver and it spun freely.