1950s 1959 cadillac propeller shaft ange

[Roman_cadillac]

I have a traditional vibration of 50-60 mph

The driveshaft is balanced, the universal joins have been replaced. The support and the bearing are original, but they are in excellent condition. New engine and transmission mounts. New tail transmission bushings.

I think the problem is in the angles of the driveshaft.I want to measure the angles and correct them.

But I do not understand the following. Is there an angle between the transmission and the first shaft or is it a straight line?

1 or 2?

[Big Fins]

I don't know of the exact angle, but I'm leaning toward illustration #1. Reason being, they put shims under the carrier bearing support to bring up the angle, The rear shaft pivots with the movement of the rear axle.

Now, do they shim the front shaft section to be in a direct line with the transmission output shaft, or is it raised a few degrees? And those shims are a bear to put in too. Taping them to the carrier support and reinstalling the shaft then driving it is about the only way to find out

[Roger Zimmermann]

If there is no angle between the transmission and firt shaft, the universal joint will be soon dead because it must have an angle to stay fit.. For cars for which the output shaft is amost at zero degree, a rubber with fabric disk is used.
Some years ago, I saw an interesting article explaining how drive shaft angles are managed. Maybe if you try in Google you will find it.
In short, the correct way for your car is the illustration 2.
Now you have two people who responded and two different answers...Who is right?

[Big Fins]

Is it possible that the shims raise the rear above the transmission output? That way you can create an angle in which to circulate the needles and give the rear shaft more travel.

[The Tassie Devil(le)]

To get the correct angles in these cars, one has to look really hard at the condition of all areas that have a relationship to the positioning of the Engine, Trans, intermediate drive shaft bearing and Rear End.

When these cars were brand new, they ran perfectly, and as they age, problems arise.

Engine Mounts sag, Trans mounts sag, Centre Bearing mount sags, and all the links at the Diff sag.   BUT, many people forget about the upper control arm and ball joint that controls the angle of the diff.

In my '60 CDV, I was chasing the same vibrations, and it turned out that the main culprit was that ball joint.  It was totally shot.   Notice that the steel hole was out of shape.   This joint was that loose.

Bruce.

[Moody]

If memory serves right, I believe, on here, someone resolved this issue by slotting the carrier bearing mounting holes so the bearing would slide sideways a bit to achieve an angular difference.

[Cadillac Jack 82]

Wish I took photos of various stuff when I gave Shelley a lucas oil change plus basic maintenance.  The biggest thing with any vibrations is the shaft bearing...and it appears that this one was done sometime in the recent past.  The rear end ball joint definitely needs replacing but thats a whole animal within itself.  Greasing the fittings massively helped with sound quality and ride. 

[Dr.59Caddy]

Did you try to put it in neutral when it starts to vibrate?...If so, did it stop vibrating?..Could be the center support bearing?...Unbalanced wheels too?...