I Broke it!

[haywire 440]

Don’t discount an issue with a tire. A slipped belt or a sudden bulge could be responsible. I know, it happened to me on the highway. Everything thing was fine, cruising along, suddenly a terrible vibration. The rear passenger side tire blew shortly after I had slowed down. Luckily not a lot of damage to the quarter panel. Tires were in great shape, no signs of cracks but they were 15 or so years old.
Experts say to be concerned after only 10 years.
I’m glad to hear you and the Charger returned safely.

 

[Ironbuilt]

I sure hope that you didn't blow a tranny!!

 

[Cncguy1]

Looking like the U joint as one of the caps was protruding about 1/4 of an inch past the strap..

 

[wvmarv]

6oz wasn't that unusual back in the days of bias ply or retreads.

Yes it was except for the retreads you mention. I worked mounting and balancing tires back then.

 

[Cncguy1]

Problem solved! It was a u joint. But I went ahead and had a new driveshaft made. The drive shaft that was in it was a 7260 and had 7260 7290 u joints to make it work. Now I have a 7290 driveshaft.

 

[Potts]

That's good.
Can't go wrong w a fresh drive shaft either.