I was doing a service on my H2 and decided to check my wheel bearing they were both fine but my idler arm had a lot of play in it so I put on of them on at the same time. 46000 miles on my truck. The rest of the front end parts were fine. It might be a good idea to check your idler arm if you have 40000 miles or so. I also put amsoil in the front and rear diffs.