Clutch chattering

[UPJOHN]

Since the temperature has been above freezing my clutch has a slight chatter in low gear when I first take off. After driving a few miles it doesn't chatter.
I'm thinking I have a rear main leak and a small amount of oil is leaking onto my flywheel. I don't see any oil on my bell housing yet.

 

[Chris]

That could be the case. This has happened on vehicles I've owned in the past, but I always just ignored it as it never seemed to be too persistent.