Guys! im new to this site so still getting my head around it all. ive got a question that im sure all of you YD25 D40 owners have pondered!!!! my D40 navara 2007 with the YD25 fitted now has 160,000 kms on it and i have never touched it!!! literally have only just put a clutch in it 3months ago. the thing runs like a clock no foreign noises or rattles, just typical diesel rattles. ive been told that i should consider doing a double row chain conversion kit to it?????? are they really that bad????? there are thousand on the road surely there not all needing them?? the point is why spend 2.5K on an engine that isnt broke??? yes i understand that if you run the gauntlet an dodge it, it may cost you more. but ****!! they cant be that bad if it was gonna fail wouldnt it already have??? i change oil and filter every 5000 religously an i flog the piss out of the car and drive it the way it should! ps i use penrite oil. guys help with some knowladge!!!!!!