I have a customer who swears by these products, especially the synthetic tube grease. They run it in logging equipment and have almost no pin and bushing wear. Running the synthetic gear lube in truck rear-ends has almost stopped major repairs.
Just an FYI. There is a Schaeffer's dealer in Sherwood also. He stocks a full line of products with better prices than those listed previously. Lots of people swear by it, but my 6.0 hates the 5-40 for whatever reason. I'll stick with Motorcraft (it's just something about that damn blue Ford blood).