I have synthetic oils (all Amsoil) coming during the next week for the engine, front and rear axles, transfer case and the NV5600. I also have a single by-pass system coming. My truck has almost 43,000 and I have no idea what's been used in it before I bought it. I've had the valve cover off to change the injectors and it was very clean. I intend on using oil analysis and extended drain. Actually I never intend on changing the oil unless the analysis says to. I will change the filters regularly.
My question is do I just need to drain everything real good and put in the new oils or do I have to flush out the old oils? I'm thinking that because the truck doesn't have many miles on it and because it is clean inside the engine that there is no need to flush it. I'd actually prefer not to flush it but I will if it is necessary.
My question is do I just need to drain everything real good and put in the new oils or do I have to flush out the old oils? I'm thinking that because the truck doesn't have many miles on it and because it is clean inside the engine that there is no need to flush it. I'd actually prefer not to flush it but I will if it is necessary.