When going to change a drive belt on these models they are a nightmare, Usually the little shock absorber tensioner fails and you will need to change the whole tensioner. People go for the cheaper part so the cheapest part is a Gates 39214 Drive belt tesioner, however when you buy this cheap part you need to add the drive belt that they say suits the pulley @ $90.00 as the pulley is larger than the original. Next problem is the design of this engine as all the pulleys the drive belt runs on have what we call belt keepers. Belt keepers are a higher ridge pulley designed to keep the belt true to the belt grooves, but if you use the belt recommended ( 7PK1640) you will find this belt runs short, so you cannot get the belt over the keepers, all pulleys in nissans have keepers unlike everything else that has one pulley that the keeper is left off in order so you can get the new belt onto the pulley, the nissan engineers must have had a day off when designing this set up. This engine was partly designed by English engineers, This explains why there is problems as they really must be mummys boys to get them into engineering school, they create more problems with their designs, not solutions. So if you insist on the cheaper Gates tensioner then the recommended belt 7PK1640 will not fit, you need a 7PK1643 that is not available and the 7PK1645 is too large, it will fit but the tension will be too poor. The remedy using the cheaper tensioner is to remove the original pulley, replace the bearing and install the old pully to the new gates tensioner. This way when the belt breaks or after it's worn you will be able to get the correct belt when you quote your rego number or the other option you have is to buy the more expensive pulley or genuine pulley. The extra time needed to try and make this cheap tensioner fit far outweighs the extra cost of buying the tensioner that does fit. I've contacted Gates about this and they don't want to know about it, blaming this individual Patrol to my problem. But this is what i have experienced on at least 5 other models, so it's not a particular vehicle that causes this problem. It's the chinese lack of quailty that is infecting the automotive industry! My advise is buy a genuine belt tensioner or fork out a few extra for the correct size pulley, unless you want to go crazy rolling around on the grass in someone's driveway with dog shit stuck to your hair, is it really worth the stress?