I can tell you I have never been a fan Al Cass. Synthetic oils last longer and do more for noisier valves. If what DrunkIQ says doesn't help, I would try a good synthetic oil. IMO, there is none better than Zaja Blue. It is available at one of the TM sponsors,
www.slidebone.com The prices there include shipping so they seem a little higher, but in reality when you compare them to others after they add shipping they are close. Irvin is a nice guy at slidebone too.
Jim