Driveline vibration

[Steves LX]

So I changed out my clutch and flywheel last night and fixed my tranny. I drove the car to work today and noticed under certain RPM's or putting the car under a heavy load I get a lot of vibration up thru the shifter handle. It even chatters if I take my hand off of it under a decent load. If you put it in neutral while rolling down the hywy its gone. I also noticed it doesn't really vibrate at all in 5th gear. Its really only in 1-4 gears. I double checked everything last night to make sure everything was tight. I thought maybe it was my aluminum driveshaft but when I put it back in last night I put it back exactly where it was when I took it out. Any ideas as to what this may be?

[Timido]

Did you mark your driveshaft to the pinnion when you removed it? Try Takeing the bolts out of the driveshaft. Turn the driveshaft 1/4 turn then put the bolts back in.

[MFIELD]

I was thinking the same thing but turning it 180 degrees