It sounds like you're trying to go cheap. Don't do it. Where maintaining your trains is concerned, you only want to use quality products. Labelle's 106 and 108 are completely different products with different applications, and yes, you should get both. Grease (106) is used for gears, oil (108) is used for other parts of the drive train. And for couplers and axles, most of us would recommend a dry graphite lubricant.So can I get away with only using 106? Or should I use that and 108?