Oiling that clutch shaft is not something I'd recommend, David. The oil traps dirt and then acts like valve grinding paste, wearing the shaft and the clutch drive disks. There are other treatments for sticking clutches that are likely to do less long-term harm. Oiling it is very easy and inexpensive to do, however, which is probably why some dealers seem to like to do it.
Several Outdoorking members have had worn clutch facings (worn to the stage where they needed to have the shim stack adjusted - most of them did not need new facings), but I do not know the age of their machines. In normal service (in other words, being driven all the time with the clutch fully engaged), they do seem to last a number of years before needing that adjustment. My concern in your case was the much larger engine, and the continual working on steep slopes, neither of which applies to most of the Greenfields we hear about.
Since your problem was a slipping belt, I think your difficulties are over. If it slips again at some time, either adjusting the belt (manually moving that spring-loaded idler near the clutches, much as you did this time) or replacing the belt, should be effective. Working on the clutches is a bit difficult with the Greenfield system, but the belts do not seem to be much more difficult to work on than other mowers.
Since this problem has been solved, I'll close this thread.
