I've seen these non-contact laser RPM gauges - basically, you put a shiny sticker (sometimes you don't need the sticker) on something you want to measure, point the RPM gauge at it (decent ones have a builtin laser pointer), and you get an RPM reading. The spec I've seen for the clutch is 1/2 engine RPM to about 3K on the engine. If you have a lot less than that, you have a problem. Note that this doesn't test the "lockup" capability of the clutch - but it's a nearly labor-free, quick, fairly safe test. Harbor Freight occasionally has these on sale, and they are all over eBay. I've been very happy with the non-contact IR temperature gauge I picked up there - for $10. It seems very accurate from 10-80 F and I have no reason to think that it doesn't do as well throughout it's rated range. Any thoughts?