Hi,

I’m not familiar with the 700’s driveshaft as I have only 240s.

I have to say that it’s unusual to see that many weights stuck onto a driveshaft to begin with.

From that scene I’m visualizing it appears that someone was trying to balance it and that didn’t know what the heck they were doing after it left the factory.

In the factory, each length of tube is made to its required length with a trimmed in bore made to make both outsides or insides too make it run rather true.
All mechanical tubing can have lopsided areas of density. Side to side and from end to end shifting in rotation about an axis. That’s call resonated shifting.
Similar too two planes of balancing in our tires and the rims. The Old Bubble balance is only in one plane technically.

On tubing Some small amount run out is inevitable from end to end and there’s always a density issue.
Between these two it is what makes it out of balance.
A small amount of either gets compounded with radius from center and speed of two forces, centrifugal and centripetal from end to end of each section.
Drivelines change in driving angles of motion, so balancing is a must.
Most tubes are made within a certain wall thickness tolerance so it’s not that much or should be?
Each piece is put pit on spud ends ends by plugs or caps that have a center hole to hold the shafts in a balancer.
It is then spun by a semi rigid drive to locate the shafts in a plane in a relation to the end supports and the driving head.
Sensors in the supports and in the driving head read and oscillation movement from a zero plane of calibration.
Removing metal or a adding weight are the options.
If it’s a lot the metal needed to be removed, do it first.
Within that, It all depends on an items structural integrity and ease of doing an adjustment.

Having whole bunch of weights added is not a good thing, for the most part.
Production facilities runs batches at a time. Most metal stock can have traits develop as numerous variations. Us humans know this so they see trends and adjust for them quite well.
Having an aware and skilled workforce paying extra attention can be expedient in most aspects of production.
Even today, Not everything can or should be, run by num nuts.
Even Artificial Intelligence machinery will be needing some of the “real stuff” to make up for its errors.

All those weights bother me as you can see, as it’s a tell that something must be wrong.
So if that was what was under the car and you lost a significant weight or got it out of phase, this is what happens.
You also do not want a stiff joint in one axis plane as it will affect the balance or even the readings on the machine for sure. How much in a car with an unknown active suspension is a tough call.
Don’t be surprised if they decide to change a universal joint. At least you are aware of that going in!

Was this car wrecked or had things changed or modified?
Maybe it got tweaked in a sudden load change?
Is it really rusty outside or in like ever been submerged or struck from underneath?
If so, the weights are saying, this baby, has been worked on.

Remember what I said, that a dynamic balancer using a semi-ridged drive coupler as they do not want the driving head bearings to impart any fluctuations into the scheme.
If the newly balanced shaft with hardly any weights, This is saying they did a good job and they salvaged it.
If you still have the problem Get suspicious towards the other ends of the car suspension or a transmission mount resonating. Very unique if it’s that from my standpoint.

Keep us in the loop.

Phil