It could deffinately be the rear main because if your rear main goes out it WILL get oil all over your clutch and flywheel, causing it to slip pretty badly. That could describe the jerkiness. as far as pulling the oil pan to replace the rear main seal, that is not necessary. just take the transmission off and you can access the rear main seal just fine. But the rear main seal might not be your only leak. the oil pan gasket can also leak into the bellhousing causing your clutch to slip. while you have the transmission off you might as well replace the oil pan gasket too. And you also dont need a pilot bearing puller to replace either one of those seals, but if you have your transmission removed you might as well check your pilot bearing and throwout bearing while you are in there!
