went through p1217 5-6 times in the first 4 years - 2015 HC M6 - 2 complete replacements, one software update, 3 springs only, and lastly a complete replacement, all driver's side. Lots of corrosion found in every case. Last one in early '19 [complete replacement] seems to have solved the problem [also replaced pass side at that time due to severe corrosion]. still looked healthy when I eventually got around to the CAT recall in early '22, and looking good at last oil change, though not as thorough an examination lying on the ground vs up on a lift [coming up on 60000 miles]