727 output shaft bearing worn? VIDEO

Tracing down a high speed vibration 80+ mph, 1st order driveshaft vibration on EVA tool.

Spicer 1350 slip yoke https://www.actionmachineinc.com/products/3-3-3931x?variant=37912097733

Driveshaft is a Dynotech. built to 69 Plymouth B-body length.

With the driveshaft installed in the transmission, the slip yoke can be pushed up and down .025 https://www.youtube.com/watch?v=va73VUAmGes

With the driveshaft removed, the output shaft can be moved .025-.030. https://www.youtube.com/watch?v=GKS-x6wtOkU

Does the output shaft bearing require replacement?

My opinion is that the bushing is shot, but what about the bearing?

Thanks

Timely post Nitro, I kinda have the same issue, ?? Hence my post on yoke length

Have your driveshaft checked.

Several years ago I mini tubbed my Dart, installed a new S-60 and a built to spec Dynotech driveshaft. I chased a vibration for five or six years and nothing I tried helped. I had the transmission out of the car a couple years ago and on a whim decided to take my driveshaft to a local shop to have it checked out. It was way out of balance and required a large weight on each end. My vibration is gone.

I'll never use or recommend Dynotech again, that shaft was over $450 and there is no excuse for it being out that bad.

Replace your tailstock bushing. That ball bearing forward of that is not meant to control that output shaft "wiggle".

And, with a vibration, check that output housing for cracks, 'cause that is what they do.

That bushing isn't expensive and as said, have the driveshaft checked
I had a new driveshaft built early this year and the run out was so bad that the vibration broke the output shaft housing.

I've never seen or heard of a 727 output shaft moving like yours does
Me thinks you have several problems now, not just one
Sorry
You need to get it fixed before it gets worst and hurts you or the car or both

Output shaft bearing is a ball bearing, not really meant to control "wiggle". Just a support between the rear support and the tailshaft bushing. You can try a bushing, but I lean towards the shaft not being 100% right for a high frequency vehicle speed related "buzz".

Have it checked. BUT at 1:1 in high gear the shaft is spinning at engine speed (or near with an auto) At 80MPH, the shaft is spinning ~4000RPM, maybe, depending on the rear gear. Most shops can't spin them nearly that fast or hold a tight enough tolerance. I would do what I had to do to get it to someone who can do a high speed check and/or balance before tearing the whole car apart.

I've had a shaft that was built with one (or both) end slightly off center, .010-.015 maybe. It would balance up and be OK for awhile, but the buzz would slowly reappear over half a season at 7000+ RPM. Got tired of it, threw it in the scrap, got a new aluminum unit, problem solved. Smooth for years after that. A bad shaft is a time bomb.

Also, in my experience, if the rear bushing gets too loose (high mileage, etc.) it will allow the yoke to move around enough to create an oil leak at that seal. If there is no evidence of the yoke moving beyond what the seal can control (leak), I would look at the shaft. Also, had a shaft out of balance/off center far enough that the yoke was "whipping" or "wallowing" around in the bushing. Evidence of that was a bushing that looked like crap and a smear of bushing material on one side of the yoke surface.