This is what I have found out. I went an oil company here in town and they told me that GL-5 has sulfur added to it and there wasn't any sulfur in GL 2,3,4. The sulfur, according to this company can damage yellow metals.
Mobile Oil has a produce called Tran HD-50 that is used by trucking companies. It has no sulfur and gets about the same thickness as 90 weight.
Its only available in 5 gal. pails.
I went to Bomgaards (fleet farm store) they had 2 gallon jugs CL 4 at $20.00
It was 90 weight.
Then I went to ORielly's and they had 1 gal. at $19.00, CL-4, weight 140.
That's what I bought, I wanted the heavier product even tho I had the new gaskets and seals install to avoid leaks later on. Tractor Supply might have a better deals?? How much was NAPA shipped in to you?
