How much gear lube to add?

[Waterloo]

(07-06-2016 )simon999 Wrote:  It would be interesting too see how the oil sample looks gear oil in the engine

I sample mine at nearly every oil change, mandate is removed and was the same time I started using the Sta-Lube gear oil. The oil samples were very good up until my motor failed due to the head issue. When the motor was disassembled, all of the parts and pieces looked as good as Rawze's, very little if any wear, the cams looked new. The lower end was just starting to show wear. Pistons and liners were very nice. But, the one thing I did find in the History of this particular truck, is that the two previous owners were religious about the oil changes, every 12,000 miles, and it showed internally. They always ran Rotella T 15w-40.

When I switched to using gear oil, the oil analysis started looking better, what little metals I had actually started dropping over time. I did have one spike in copper, but I believe that was a glitch, and was the last oil analysis prior to my in frame. That sample was taken at a different Speedco than the one I have used for years. I attribute the spike in copper to their machine, as the parts were showing little to any wear when we got the motor apart at roughly 900,000 miles. I now swear by the gear oil, and have no plans of discontinuing its use. I should have my first sample in a few weeks when I change the oil again... We shall see.