Been driving my 1981 242 B21F -Non-turbo (m46 manual tranny) around town lately, and every now and then, if I stomp on the gas in 1st or 2nd, the clutch will slip, the engine will rev up and the car will not go any faster. There is a pretty noticable clunk both when it slips and when it re-engages. I can't really tell where the clunk is coming from, either the transmission or driveline. However, the car has no problem climbing hills in 4th and 5th, and only seems to slip when I step on it in 1st or 2nd.

Now that this is happening, I suspect the clutch, could it be oil getting on the clutch plates, or possibly a rear end/differential/driveline problem? Is there a good way to tell before I drop $400-500 on a new clutch?


Side Note: When I bought the car, the clutch pedal was riding low to the floor on it's own, and when I looked underneath, I noticed that the spring had been hooked on BACKWARDS, essentially pulling the clutch down 1/4 of the way to the floor, and thus permenantly riding the clutch. I fixed the spring a long time ago, but I figured that it probably shortened the life of the clutch.

Thanks!