98 f150 v8 4.6L. Well anyways i was on the highway and all of a sudden i heard a loud bang under my truck right between my front seats. So i get off the highway and look under my truck, and found an metal o-ring band hanging from my drive shaft. It was hanging right behind my tranny, and infron of the universial joint. Well i think this metel band was either compressed or welded onto the universial joint on the transmission. There is a little gap in the band, and when i put it over the joint, there is a little play, so i think it was compressed on. I am trying to figure out what this is for. I was thinking a weight, but if it was a weight, why would it be a solid metal band. Any ideas? Its hard to explain, but hopefully you can follow.

 

I think i know what you are talkin' about. That metal band i belive is pressed on the end of the slip yoke with a rubber insulator between that ring and the yoke. My guess would be that it is there to dampen any kind of slight vibrations that may occur in the driveshaft.
As far as getting it back on there, don't know about that. You more than likely will have to shell out some money to get a new one. It may be safe to unbolt the driveshaft at the companion flange on your pinion, slide the driveshaft out of the rear of the tranny and pull off that ring, then install the driveshaft to get you to where you can get it repaired.
Hope this helps. Maybee someone else that this has happened to can chime in.

 

YES!!!!! thats whats i'm talking about, and i was thinking about it, and i think it was just to absorb the vibration. But i wonder if it's worth putting a new one on or whatever?

 

The "band" you are referring to is a vibration dampener. Sounds like you need a new one.
I remember my 1977 Mercury had one of these on it. It never was a problem.

 

but i need to figure out if i should get a new one, and if i do how much does it run?

 

could it possbly be the bushing from your tailhousing? is there any movement of the driveshaft at the tailhousing?

 

nope.... no movement

 

Does anyone know where I can order one of those bushings/vibration dampeners online. I can't find them anywhere and don't have time to go to the dealer. Thanks