70 duster rear brake drum/vibration question

Shadowfirexz said

wouldnt it wobble at any speed and vibe in and speed in 4th then? Mine runs smooth as can be in 4th until you hit 80mph then nothing stops the vibe just lowering speed .... My bellhousing has dowls and I believe it to be aligned right. Never touched any crank bushings ever hmm.
I can’t say your wrong and I can’t say you’re right uhg, what a nightmare. Thanks I’ll keep digging

Click to expand...

I'm just saying what happened to me and what fixed it. In 1st 2nd and 3rd the input shaft is spinning at a different speed than the output shaft, so if the input wobbles the output shaft is turning slower then the vib seems to cancel it self out and you might not feel it but in 4th gear the two shafts are turning the same speed and it is like a straight shaft that gets bent in the middle, now if you put a bearing on both ends and spin it the middle swings out of round and both ends wobble. if it's not out much you might not feel it till it gets going fast enough to set up a oscillation then its hard to stop.
If you put everything in new and didn't change or check the pilot it could just be worn out. Is it a bushing or a ball bearing ?